10-Day versus 14-day bismuth quadruple therapy for first-line eradication of Helicobacter pylori infection: a randomised, open-label, non-inferiority trial

Background

Bismuth quadruple therapy is currently consensus recommendation for first-line Helicobacter pylori (H. pylori) treatment; however, the optimal duration is unknown. We compared the efficacy of 10-day bismuth quadruple therapy with that of 14-day bismuth quadruple therapy for first-line eradication.

Methods

For our multicentre, parallel randomised, open-label, and non-inferiority study, we recruited H. pylori treatment-naïve patients from one medical centre and one teaching hospital in Taiwan. Patients were randomly assigned (1:1) to receive 10-day (PBMT-10) or 14-day (PBMT-14) bismuth quadruple therapy. The primary outcome was the eradication rate as determined by intention-to-treat (ITT) and per-protocol (PP) analyses. The eradication rates between the two groups were compared using a one-sided α value of 0.025 and a non-inferiority margin of 7%. The secondary outcomes were the rate of adverse effects. The trial is registered with ClincialTrials.gov (NCT04527055).

Findings

From August 3, 2020 to April 28, 2023, 313 H. pylori treatment-naïve patients (PBMT-10 = 157; PBMT-14 = 156) were enrolled. 35 patients were excluded from PP analyses. The eradication rates (95% CI) for PBMT-10 and PBMT-14 were respectively 92.4% (88.2%-96.5%) and 92.9% (88.9%-97.0%) by ITT analyses, and 97.9% (95.5%-100.0%) and 99.3% (97.8%-100.0%) by PP analyses. The eradication rates for PBMT-10 were non-inferior to those for PBMT-14 (absolute difference [lower boundary of the one-sided 97.5% CI] -0.6% [-6.7%], PNI = 0.020 in ITT analyses, -1.4% [-5.8%], PNI = 0.007 in PP analyses). The rates of overall adverse effects (54.1% versus 57.1%, P = 0.604) were similar between the two groups; nevertheless, the rates of dizziness (18.5% versus 34.0%, P = 0.003) and vomiting (4.5% versus 12.8%, P = 0.008) were lower in PBMT-10 than in PBMT-14.

Interpretation

The 10-day bismuth quadruple therapy was non-inferior to the 14-day therapy as a first-line treatment for eradicating H. pylori infection and had no different rates of overall adverse effects, but less serious adverse events in terms of dizziness and vomiting.

Funding

The National Science and Technology Council and Ministry of Health and Welfare, Taiwan.

Wearable Integrated Volitional Control Electrical Stimulation Device as Treatment for Paresis of the Upper Extremity in Early Subacute Stroke Patients: A Randomized Controlled Non-inferiority Trial

OBJECTIVE

To investigate the effect of a wearable integrated volitional control electrical stimulation (WIVES) device that has been developed as more compact and simpler to use in daily life compared with conventional integrated volitional control electrical stimulation (IVES) devices.

DESIGN

Randomized controlled non-inferiority trial.

SETTING

Convalescent rehabilitation ward.

PARTICIPANTS

Patients with paresis of the upper extremity (UE) after early subacute stroke (N=20).

INTERVENTIONS

Eligible patients were randomized to receive IVES treatment or WIVES treatment for 8 hours per day for 28 days in daily living, in addition to standard rehabilitation treatment. In both groups, the extensor digitorum communis on the affected side was the target muscle for stimulation.

MAIN OUTCOME MEASURE

Primary outcomes were assessed with Fugl-Meyer Assessment of the UE (FMA-UE) before and after treatment. Non-inferiority was determined with a specified margin of non-inferiority.

RESULTS

Twenty patients completed the trial (IVES group: n=10, WIVES group: n=10). FMA-UE improved in both groups. The mean change in FMA-UE was 4.7 for the IVES group and 6.0 for the WIVES group (P>.05, 95% confidence interval: -6.73 to 4.13). The mean difference between the groups was 1.3, and the upper 95% confidence interval did not exceed the non-inferiority margin.

CONCLUSION

The effectiveness of WIVES treatment is non-inferior to that of IVES treatment. As a portable device, IVES may facilitate the use of affected upper extremities in daily living and may help improve paresis of the UE.

Non-inferiority of intermittent theta burst stimulation over the left V1 vs. classical target for depression: A randomized, double-blind trial

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) targeting the visual cortex (VC) has shown antidepressant effects for major depressive disorder (MDD) in sham-controlled trials, but comparisons with rTMS targeting the left dorsolateral prefrontal cortex (DLPFC) are lacking. We aimed to determine the non-inferiority of intermittent theta-burst stimulation (iTBS) over VC vs DLPFC for MDD.

METHODS

Participants randomly received navigated iTBS over the left V1 or the left DLPFC twice daily for 14 days with a 3-month follow-up. The primary outcome was change in Hamilton Depression Rating Scale (HAMD-17) score from baseline to treatment end, with 2.5 points as the non-inferiority margin. Secondary outcomes included: improvement in Montgomery-Asberg Depression Rating Scale (MADRS), Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA); response and remission rates; suicidal ideation and adverse events.

RESULTS

Of 75 randomized patients, 67 completed full treatment, including 52 first-episode patients and 15 relapsers. The primary outcome indicated the non-inferiority of VC (adjusted difference 1.14, lower 97.5 % CI -1.24; p = .002), confirmed by improvements in objective cognitive task and protein levels, as did most secondary outcomes. Reduced suicidal ideation after treatment, incidence of eye discomfort and pain score were lower in the VC group.

CONCLUSIONS

Left VC iTBS has the potential to be non-inferior to DLPFC iTBS in most first-episode MDD in improving depressive symptoms and cognitive function, with less suicidal ideation and adverse events.

LIMITATIONS

Given the limited sample size, the lack of a sham control and the use of antidepressants, the findings should be interpreted with caution.

The efficacy of intra-articular triamcinolone acetonide 10 mg vs. 40 mg in patients with knee osteoarthritis: a non-inferiority, randomized, controlled, double-blind, multicenter study

BACKGROUND

Intra-articular (IA) corticosteroid injection is recommended in refractory knee osteoarthritis patients. However, 40-mg of triamcinolone IA every 3 months for 2 years reduces cartilage volume as compared to saline IA.

OBJECTIVE

To determine the non-inferiority of 10-mg versus 40-mg of triamcinolone acetonide (TA) for treatment of pain in symptomatic knee osteoarthritis at week 12.

METHODS

This was a double-blind, randomized, controlled trial conducted in 84 symptomatic knee osteoarthritis patients. The 10-mg or 40-mg of TA were 1:1 randomized and injected to the affected knees. The primary outcome was the 12-week difference from baseline in pain VAS, with a pre-specified lower margin for non-inferiority of 10 mm. The measuring instruments used were: Visual analog scale (VAS: 0-10), modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), EuroQol Group 5 Dimensions (EQ5D), Knee Injuries and Osteoarthritis Outcome Score (KOOS) questionnaire, chair standing test and 20-m walking time at baseline, at week 4, and week 12 after randomization. Adverse events were recorded.

RESULTS

Baseline characteristics were similar between two groups. The mean differences of pain VAS (95% confidence interval: CI) between the two groups at baseline and week 12 were 0.8 (-0.8, 2.4) with p of 0.002 for non-inferiority. There were no differences in pain reduction and quality of life improvement between 10-mg and 40-mg groups. The mean differences (95%CI) of WOMAC, KOOS pain, EQ5D and KOOS quality of life between baseline and week 12 were 0.4 (-1.1, 1.9). -8.7 (-21.3, 3.9), 1.3(-7.1, 9.6) and 1.8 (-11.5, 15.0), respectively. There were significant improvements in pain and quality of life between baseline and week 12 in both groups.

CONCLUSION

The 10 mg of TA is non-inferior to 40 mg TA in improving pain in patients with symptomatic knee OA. Both 10 mg and 40 mg of TA significantly improved pain and quality of life in patients with symptomatic knee OA.

TRIAL REGISTRATION

TCTR, I TCTR20210224002. Retrospectively registered 24 February 2021, http://www.thaiclinicaltrials.org/show/TCTR20210224002.

[The correct way to read and understand published clinical trial results]

Correct interpretation of clinical trial results is important. Overall survival was once considered the primary endpoint for neoplastic disease, but surrogate endpoints are increasingly being used for diseases whose prognosis has improved. This is due to the longer trial duration required to obtain conclusions and to poor statistical power. Clinical decision-making in practice is also shifting to using these surrogate endpoints. In clinical trials, eligibility criteria are set to obtain differences between arms. However, this does not mean that results should only be applied to eligible populations, as it is not realistic to conduct a clinical trial in patients with all possible characteristics. Rather, results should be applied to patients who do not meet the eligibility criteria, with careful consideration. A single clinical trial often presents the results of many subgroup analyses, but the main conclusion should not be judged differently by subgroup. The purpose of subgroup analysis is to find potential confounders that interact with the conclusion, and results of subgroup analysis should not be overestimated. Non-inferiority trials have become increasingly common in recent years, and their importance is not limited to demonstrating the non-inferiority of the primary endpoint. Specifically, they are also important for understanding the benefits in the experimental arm outside those in primary analysis. Some secondary endpoints are very important for making conclusions about these benefits.

Safety and efficacy of a cardiovascular polypill in people at high and very high risk without a previous cardiovascular event: the international VULCANO randomised clinical trial

BACKGROUND

Cardiovascular (CV) polypills are a useful baseline treatment to prevent CV diseases by combining different drug classes in a single pill to simultaneously target more than one risk factor. The aim of the present trial was to determine whether the treatment with the CNIC-polypill was at least non-inferior to usual care in terms of low-density lipoprotein cholesterol (LDL-c) and systolic BP (SBP) values in subjects at high or very high risk without a previous CV event.

METHODS

The VULCANO was an international, multicentre open-label trial involving 492 participants recruited from hospital clinics or primary care centres. Patients were randomised to the CNIC-polypill -containing aspirin, atorvastatin, and ramipril- or usual care. The primary outcome was the comparison of the mean change in LDL-c and SBP values after 16 weeks of treatment between treatment groups.

RESULTS

The upper confidence limit of the mean change in LDL-c between treatments was below the prespecified margin (10 mg/dL) and above zero, and non-inferiority and superiority of the CNIC-polypill (p = 0.0001) was reached. There were no significant differences in SBP between groups. However, the upper confidence limit crossed the prespecified non-inferiority margin of 3 mm Hg. Significant differences favoured the CNIC-polypill in reducing total cholesterol (p = 0.0004) and non-high-density lipoprotein cholesterol levels (p = 0.0017). There were no reports of major bleeding episodes. The frequency of non-serious gastrointestinal disorders was more frequent in the CNIC-polypill arm.

CONCLUSION

The switch from conventional treatment to the CNIC-polypill approach was safe and appears a reasonable strategy to control risk factors and prevent CVD. Trial registration This trial was registered in the EU Clinical Trials Register (EudraCT) the 20th February 2017 (register number 2016-004015-13; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2016-004015-13 ).

Immunogenicity and safety of two novel human papillomavirus 4- and 9-valent vaccines in Chinese women aged 20-45 years: A randomized, blinded, controlled with Gardasil (type 6/11/16/18), phase III non-inferiority clinical trial

BACKGROUND

Human papillomavirus (HPV) infections were the main cause of anogenital cancers and warts. HPV 6/11/16/18 vaccines provide protection against the high-risk types of HPV responsible for 70% of cervical cancers and 90% of genital warts. This randomized, blinded, non-inferiority phase III trial was to determine whether immunogenicity and tolerability would be non-inferior among women after receiving two novel 4- and 9-valent HPV vaccines (4vHPV, HPV 6/11/16/18; 9vHPV, HPV 6/11/16/18/31/33/45/52/58) compared with those receiving Gardasil 4 (4-valent).

METHODS

1680 females between 20 and 45 years were randomized in a 2:1:1 ratio to 20-26, 27-35, or 36-45 y groups. Subjects then equally assigned to receive 4vHPV, 9vHPV or Gardasil 4 (control) vaccine at months 0, 2, and 6. End points included non-inferiority of HPV-6/11/16/18 antibodies for 4vHPV versus control, and 9vHPV versus control and safety. The immunogenicity non-inferiority was pre-defined as the lower bound of 95% confidence interval (CI) of seroconversion rate (SCR) difference > -10% and the lower bound of 95% CI of geometric mean antibody titer (GMT) ratio > 0.5.

RESULTS

Among the three vaccine groups, more than 99% of the participants seroconverted to all 4 HPV types. The pre-specified statistical non-inferiority criterion for the immunogenicity hypothesis was met: all the lower bounds of 95% CIs on SCR differences exceeded -10% for each vaccine HPV type and the corresponding lower bounds of 95% CIs for GMT ratios > 0.5. Across vaccination groups, the most common vaccination reaction were injection-site adverse events (AEs), including pain, swelling, and redness. General and serious AEs were similar in the three groups. There were no deaths.

CONCLUSIONS

This study demonstrated that the novel 4- and 9-valent HPV vaccination was highly immunogenic and generally well tolerated, both of which were non-inferior to Gardasil 4 in immunogenicity and safety.

Transitioning to active-controlled trials to evaluate cardiovascular safety and efficacy of medications for type 2 diabetes

Cardiovascular (CV) outcome trials (CVOTs) of type 2 diabetes mellitus (T2DM) therapies have mostly used randomized comparison with placebo to demonstrate non-inferiority to establish that the investigational drug does not increase CV risk. Recently, several glucagon-like peptide 1 receptor agonists (GLP-1 RA) and sodium glucose cotransporter 2 inhibitors (SGLT-2i) demonstrated reduced CV risk. Consequently, future T2DM therapy trials could face new ethical and clinical challenges if CVOTs continue with the traditional, placebo-controlled design. To address this challenge, here we review the methodologic considerations in transitioning to active-controlled CVOTs and describe the statistical design of a CVOT to assess non-inferiority versus an active comparator and if non-inferiority is proven, using novel methods to assess for superiority versus an imputed placebo. Specifically, as an example of such methodology, we introduce the statistical considerations used for the design of the "Effect of Tirzepatide versus Dulaglutide on Major Adverse Cardiovascular Events (MACE) in Patients with Type 2 Diabetes" trial (SURPASS CVOT). It is the first active-controlled CVOT assessing antihyperglycemic therapy in patients with T2DM designed to demonstrate CV efficacy of the investigational drug, tirzepatide, a dual glucose-dependent insulinotropic polypeptide and GLP-1 RA, by establishing non-inferiority to an active comparator with proven CV efficacy, dulaglutide. To determine the efficacy margin for the hazard ratio, tirzepatide versus dulaglutide, for the composite CV outcome of death, myocardial infarction, or stroke (MACE-3), which is required to claim superiority versus an imputed placebo, the lower bound of efficacy of dulaglutide compared with placebo was estimated using a hierarchical Bayesian meta-analysis of placebo-controlled CVOTs of GLP-1 RAs. SURPASS CVOT was designed so that when the observed upper bound of the 95% confidence interval of the hazard ratio is less than the lower bound of efficacy of dulaglutide, it demonstrates non-inferiority to dulaglutide by preserving at least 50% of the CV benefit of dulaglutide as well as statistical superiority of tirzepatide to a theoretical placebo (imputed placebo analysis). The presented methods adding imputed placebo comparison for efficacy assessment may serve as a model for the statistical design of future active-controlled CVOTs.

SALUS-a non-inferiority trial to compare self-tonometry in glaucoma patients with regular inpatient intraocular pressure controls: study design and set-up

Purpose

The SALUS study aims to improve the healthcare situation for glaucoma patients in Germany. In order to detect diurnal intraocular pressure (IOP) fluctuations, inpatient monitoring of IOP in an eye hospital for a minimum of 24 h is the current standard. SALUS assesses the benefits of a new form of outpatient care, where IOP can be measured by the patients themselves at home using a self-tonometer. This approach should promote the patient’s health competence and empowerment within the healthcare system while reducing treatment costs.

Methods

The SALUS study is a randomized controlled, open non-inferiority trial, alongside an economic analysis, determining whether outpatient monitoring of IOP with self-tonometry is at least as effective as current standard care and would reduce treatment costs. Participants (n = 1980) will be recruited by local ophthalmologists in the area of Westphalia-Lippe, Germany, and randomized to receive 7-day outpatient or 24-h inpatient monitoring. Participants in both study arms will also receive 24-h blood pressure monitoring. Furthermore, patient data from both study groups will be collected in an electronic case file (ECF), accessible to practitioners, hospitals, and the study participants. The primary endpoint is the percentage of patients with IOP peaks, defined as levels 30% above the patient-specific target pressure. Data will also be collected during initial and final examinations, and at 3, 6, and 9 months after the initial examination.

Results

The study implementation and trial management are represented below.

Conclusion

SALUS is a pioneering prospective clinical trial focused on the care of glaucoma patients in Germany. If SALUS is successful, it could improve the healthcare situation and health literacy of the patients through the introduction of various telemedical components. Furthermore, the approach would almost certainly reduce the treatment costs of glaucoma care.

Trial registration

ClinicalTrials.gov ID: NCT04698876, registration date: 11/25/2020.

DRKS-ID: DRKS00023676, registration date: 11/26/2020.

Conversion of non-inferiority margin from hazard ratio to restricted mean survival time difference using data from multiple historical trials

The restricted mean survival time measure has gained a lot of interests for designing and analyzing oncology trials with time-to-event endpoints due to its intuitive clinical interpretation and potentially high statistical power. In the non-inferiority trial literature, restricted mean survival time has been used as an alternative measure for reanalyzing a completed trial, which was originally designed and analyzed based on traditional proportional hazard model. However, the reanalysis procedure requires a conversion from the non-inferiority margin measured in hazard ratio to a non-inferiority margin measured by restricted mean survival time difference. An existing conversion method assumes a Weibull distribution for the population survival time of the historical active control group under the proportional hazard assumption using data from a single trial. In this article, we develop a methodology for non-inferiority margin conversion when data from multiple historical active control studies are available, and introduce a Kaplan-Meier estimator-based method for the non-inferiority margin conversion to relax the parametric assumption. We report extensive simulation studies to examine the performances of proposed methods under the Weibull data generative models and a piecewise-exponential data generative model that mimic the tumor recurrence and survival characteristics of advanced colon cancer. This work is motivated to achieve non-inferiority margin conversion, using historical patient-level data from a large colon cancer clinical database, to reanalyze an internationally collaborated non-inferiority study that evaluates 6-month versus 3-month duration of adjuvant chemotherapy in stage III colon cancer patients.

Mastery versus invention learning: impacts on future learning of simulated procedural skills

BACKGROUND

Invention and mastery learning approaches differ in their foundational educational paradigms, proposed mechanisms of learning, and potential impacts on learning outcomes. They also differ in their resource requirements. We explored the relative effects of 'invent and problem-solve, followed by instruction' (PS-I) learning compared to mastery learning (i.e., standards-based training) on immediate post-test and Preparation for Future Learning (PFL) assessments. PFL assessments measure learners' capacity to use their existing knowledge and strategies to learn about and solve novel problems.

METHODS

In this non-inferiority trial, pre-clerkship medical students were randomized to either PS-I, Mastery Learning (ML), or instruction then practice (CON) during simulation-based training of infant lumbar puncture (LP). After a 2-week delay, participants returned to learn and complete a PFL assessment of simulated Knee Arthrocentesis. Two independent raters assessed performances with a 5-point global rating scale.

RESULTS

Based on our non-inferiority margin, analyses showed that for both the immediate post-test and the PFL assessment, the PS-I condition resulted in non-inferior outcomes relative to the ML condition. Results for the CON condition were mixed with respect to non-inferiority compared to either PS-I or ML.

CONCLUSIONS

We suggest cautiously that the PS-I approach was not inferior to the ML approach, based on skill acquisition and PFL assessment outcomes. With ML anecdotally and empirically requiring more time, greater faculty involvement, and higher costs, our findings question the preference ML has received relative to other instructional designs, especially in the healthcare simulation community. We encourage researchers to study the educational and resource impacts of instructional designs using non-inferiority designs.

Prospective, randomized, controlled, double-blind, multi-center, multinational study on the safety and efficacy of 6% Hydroxyethyl starch (HES) sOlution versus an Electrolyte solutioN In patients undergoing eleCtive abdominal Surgery: study protocol for the PHOENICS study

Background

Hydroxyethyl starch (HES) solutions are used for volume therapy to treat hypovolemia due to acute blood loss and to maintain hemodynamic stability. This study was requested by the European Medicines Agency (EMA) to provide more evidence on the long-term safety and efficacy of HES solutions in the perioperative setting.

Methods

PHOENICS is a randomized, controlled, double-blind, multi-center, multinational phase IV (IIIb) study with two parallel groups to investigate non-inferiority regarding the safety of a 6% HES 130 solution (Volulyte 6%, Fresenius Kabi, Germany) compared with a crystalloid solution (Ionolyte, Fresenius Kabi, Germany) for infusion in patients with acute blood loss during elective abdominal surgery. A total of 2280 eligible patients (male and female patients willing to participate, with expected blood loss ≥ 500 ml, aged > 40 and ≤ 85 years, and ASA Physical status II–III) are randomly assigned to receive either HES or crystalloid solution for the treatment of hypovolemia due to surgery-induced acute blood loss in hospitals in up to 11 European countries. The dosing of investigational products (IP) is individualized to patients’ volume needs and guided by a volume algorithm. Patients are treated with IP for maximally 24 h or until the maximum daily dose of 30 ml/kg body weight is reached.

The primary endpoint is the treatment group mean difference in the change from the pre-operative baseline value in cystatin-C-based estimated glomerular filtration rate (eGFR), to the eGFR value calculated from the highest cystatin-C level measured during post-operative days 1-3. Further safety and efficacy parameters include, e.g., combined mortality/major post-operative complications until day 90, renal function, coagulation, inflammation, hemodynamic variables, hospital length of stay, major post-operative complications, and 28-day, 90-day, and 1-year mortality.

Discussion

The study will provide important information on the long-term safety and efficacy of HES 130/0.4 when administered according to the approved European product information. The results will be relevant for volume therapy of surgical patients.

Trial registration

EudraCT 2016-002162-30. ClinicalTrials.govNCT03278548

Comparative effectiveness of guided internet-based stress management training versus established in-person group training in employees - study protocol for a pragmatic, randomized, non-inferiority trial

BACKGROUND

Occupational stress is a major public health challenge that requires a variety of evidence-based preventative approaches to increase their reach within the working population. Behavioral stress management interventions are considered an established approach for occupational stress prevention. Both in-person group-based stress management training (gSMT) and individual Internet-based training (iSMT) have been shown to be effective at reducing stress in employees. However, there remains a lack of evidence on the comparative efficacy of the newer digital format compared to well-established, in-person, group-based training. This study aims (1) to directly compare an evidence-based iSMT with an established gSMT on stress in employees, (2) to analyze the two conditions from a cost perspective, and (3) to explore moderators of the comparative efficacy.

METHODS

In a randomized, controlled, non-inferiority trial employees from the general working population will be allocated to iSMT or gSMT. The primary outcome will be perceived stress, assessed using the Perceived Stress Scale, three months after randomization. The non-inferiority margin for the primary outcome measure will be set at 2 points (Cohen's d = 0.29). This trial will also compare the two interventions from a health economics perspective, and conduct explorative analyses to identify potential effect moderators.

DISCUSSION

To reach a larger proportion of the working population, well-established gSMT should be complemented with interventions that fit today's society's increasingly digital lifestyle. The current trial will provide evidence supporting the responsible implementation of Internet-based stress management training if the digital format proves to at least be non-inferior to established group-based training. Additional explorative moderator analyses may guide future practices to aid in matching select programs with select users.

TRIAL REGISTRATION

German Register of Clinical Studies (DRKS): DRKS00024892, date of registration: 2021-04-09. Protocol version: 02, 16-10-2021.

Non-inferiority of low-dose compared to standard high-dose calcium supplementation in pregnancy: study protocol for two randomized, parallel group, non-inferiority trials in India and Tanzania

BACKGROUND

Hypertensive disorders of pregnancy are important causes of maternal morbidity and mortality, as well as preterm birth, the leading cause of death for children under 5 years globally. The World Health Organization currently recommends that pregnant women receive high-dose calcium supplementation (1500-2000 mg elemental calcium) for prevention of preeclampsia in populations with low dietary calcium intake. Trials of low-dose calcium supplementation (< 1000 mg elemental calcium/day) during pregnancy have also shown similar reductions in the risk of preeclampsia; however, no trials to date have directly compared low-dose to the standard high-dose calcium supplementation. Our objective is to assess the non-inferiority of low-dose as compared to standard high-dose calcium supplementation in pregnancy.

METHODS/DESIGN

We will conduct two independent trials in Bangalore, India (n = 11,000 pregnancies), and Dar es Salaam, Tanzania (n = 11,000 pregnancies). The trial designs are individually randomized, parallel group, quadruple-blind, non-inferiority trials of low-dose calcium supplementation (500 mg elemental calcium/day) as compared to standard high-dose calcium supplementation (1500 mg elemental calcium/day) among nulliparous pregnant women. Pregnant women will be enrolled in the trial before 20 weeks of gestation and will receive the randomized calcium regimen from randomization until the time of delivery. The co-primary outcomes are (i) preeclampsia and (ii) preterm birth; we will test non-inferiority of the primary outcomes for low-dose as compared to the standard high-dose supplementation regimen in each trial. The trials' secondary outcomes include gestational hypertension, severe features of preeclampsia, pregnancy-related death, third trimester severe anemia, fetal death, stillbirth, low birthweight, small-for-gestational age birth, and infant death.

DISCUSSION

The trials will provide causal evidence on the non-inferiority of low-dose as compared to the standard high-dose supplementation in India and Tanzania. A single tablet, low-dose calcium supplementation regimen may improve individual-level adherence, reduce programmatic costs, and ultimately expand implementation of routine calcium supplementation in pregnancy in populations with low dietary calcium intake.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03350516 ; registered on 22 November 2018. Clinical Trials Registry-India identifier: CTRI/2018/02/012119 ; registered on 23 February 2018. Tanzania Medicines and Medical Devices Authority Trials Registry identifier: TFDA0018/CTR/0010/5 ; registered on 20 December 2018.

Choosing and changing the analysis scale in non-inferiority trials with a binary outcome

Background

The size of the margin strongly influences the required sample size in non-inferiority and equivalence trials. What is sometimes ignored, however, is that for trials with binary outcomes, the scale of the margin – risk difference, risk ratio or odds ratio – also has a large impact on power and thus on sample size requirement. When considering several scales at the design stage of a trial, these sample size consequences should be taken into account. Sometimes, changing the scale may be needed at a later stage of a trial, for example, when the event proportion in the control arm turns out different from expected. Also after completion of a trial, a switch to another scale is sometimes made, for example, when using a regression model in a secondary analysis or when combining study results in a meta-analysis that requires unifying scales. The exact consequences of such switches are currently unknown.

Methods and Results

This article first outlines sample size consequences for different choices of analysis scale at the design stage of a trial. We add a new result on sample size requirement comparing the risk difference scale with the risk ratio scale. Then, we study two different approaches to changing the analysis scale after the trial has commenced: (1) mapping the original non-inferiority margin using the event proportion in the control arm that was anticipated at the design stage or (2) mapping the original non-inferiority margin using the observed event proportion in the control arm. We use simulations to illustrate consequences on type I and type II error rates. Methods are illustrated on the INES trial, a non-inferiority trial that compared single birth rates in subfertile couples after different fertility treatments. Our results demonstrate large differences in required sample size when choosing between risk difference, risk ratio and odds ratio scales at the design stage of non-inferiority trials. In some cases, the sample size requirement is twice as large on one scale compared with another. Changing the scale after commencing the trial using anticipated proportions mainly impacts type II error rate, whereas switching using observed proportions is not advised due to not maintaining type I error rate. Differences were more pronounced with larger margins.

Conclusions

Trialists should be aware that the analysis scale can have large impact on type I and type II error rates in non-inferiority trials.

Engerix-B) for hepatitis B among adults in Dhaka, Bangladesh

Worldwide Hepatitis B is known as one of the imperative causes of mortality and morbidity as well as occupational health hazard among health workers. Bangladesh is intermediate endemic country for Hepatitis B infection for which the government has introduced hepatitis B vaccination into the Expanded Programme on Immunization (EPI) nationwide since 2009 for new born children. However, the people who were born before 2009, was dependent on imported hepatitis B vaccine as there was no locally manufactured hepatitis B vaccine in Bangladesh. Hence, we conducted a randomized observer blinded non-inferiority clinical trial to assess the immunogenicity and safety of the locally manufactured Hepa-B vaccine in comparison with World Health Organization prequalified Engerix-B vaccine. Total 158 eligible adult participants were enrolled in this study with mean age of 30 and 29 years old in Hepa-B and Engerix-B groups, respectively. Both the vaccines were administered intramuscularly at 0, 1 and 6 months schedule. Baseline and post vaccination anti-HBs titers were measure at different time points. Seroconversion rate post three doses of Hepa-B vaccine was 98.67% similar to the comparator Engerix-B vaccine which was 100%. The geometric mean test ratios of both vaccines at all analysis time points were found > 0.5 predefined non-inferiority margin. Soreness at the injection site was the most common symptom for both the vaccines which resolved without any complication. No serious adverse event was reported throughout the study period. These results suggest that locally manufactured hepatitis B vaccine 'Hepa-B' vaccine is non-inferior to the well-known licensed 'Engerix-B' vaccine. ClinicalTrials.gov NCT03627507.

Lifestyle-integrated functional exercise to prevent falls and promote physical activity: Results from the LiFE-is-LiFE randomized non-inferiority trial

BACKGROUND

The 'Lifestyle-integrated Functional Exercise' (LiFE) program successfully reduced risk of falling via improvements in balance and strength, additionally increasing physical activity (PA) in older adults. Generally being delivered in an individual one-to-one format, downsides of LiFE are considerable human resources and costs which hamper large scale implementability. To address this, a group format (gLiFE) was developed and analyzed for its non-inferiority compared to LiFE in reducing activity-adjusted fall incidence and intervention costs. In addition, PA and further secondary outcomes were evaluated.

METHODS

Older adults (70 + years) at risk of falling were included in this multi-center, single-blinded, randomized non-inferiority trial. Balance and strength activities and means to enhance PA were delivered in seven intervention sessions, either in a group (gLiFE) or individually at the participant's home (LiFE), followed by two "booster" phone calls. Negative binomial regression was used to analyze non-inferiority of gLiFE compared to LiFE at 6-month follow-up; interventions costs were compared descriptively; secondary outcomes were analyzed using generalized linear models. Analyses were carried out per protocol and intention-to-treat.

RESULTS

Three hundred nine persons were randomized into gLiFE (n = 153) and LiFE (n = 156). Non-inferiority of the incidence rate ratio of gLiFE was inconclusive after 6 months according to per protocol (mean = 1.27; 95% CI: 0.80; 2.03) and intention-to-treat analysis (mean = 1.18; 95% CI: 0.75; 1.84). Intervention costs were lower for gLiFE compared to LiFE (-€121 under study conditions; -€212€ under "real world" assumption). Falls were reduced between baseline and follow-up in both groups (gLiFE: -37%; LiFE: -55%); increases in PA were significantly higher in gLiFE (+ 880 steps; 95% CI 252; 1,509). Differences in other secondary outcomes were insignificant.

CONCLUSIONS

Although non-inferiority of gLiFE was inconclusive, gLiFE constitutes a less costly alternative to LiFE and it comes with a significantly larger enhancement of daily PA. The fact that no significant differences were found in any secondary outcome underlines that gLiFE addresses functional outcomes to a comparable degree as LiFE. Advantages of both formats should be evaluated in the light of individual needs and preferences before recommending either format.

TRIAL REGISTRATION

The study was preregistered under clinicaltrials.gov (identifier: NCT03462654 ) on March 12th 2018.

Ultrasound-guided internal jugular venipuncture using pocket-sized versus standard ultrasound devices: a prospective non-inferiority trial

PURPOSE

Pocket-sized ultrasound devices (PUDs) are commonly adopted for bedside use despite their inferior performance compared with standard ultrasound devices (SUDs). We investigated the non-inferiority of PUDs versus SUDs for ultrasound-guided internal jugular venipuncture.

METHODS

All patients undergoing scheduled surgery with general anesthesia and internal jugular vein catheter placement were prospectively included in this randomized non-inferiority trial to compare the qualities of the internal jugular venipuncture between the PUD group (Group P) and SUD group (Group S). The primary endpoint was puncture time, and the secondary endpoints included number of punctures, needle and guidewire visibility, and anatomic visibility.

RESULTS

Fifty-two patients were randomized to one of the two groups (26 per group). The mean (SEM) puncture time was 56.4 (10.9) s in Group P and 45.5 (4.0) s in Group S. The mean difference of 10.9 s was within the prespecified non-inferiority margin of 100% (two-sided 95% CI: - 12.9-34.6, upper limit of the 95% CI: 45.5) for puncture time. The mean (SEM) number of punctures was 1.15 (0.12) times in Group P and 1.12 (0.06) times in Group S. The difference of 0.04 punctures was within the prespecified non-inferiority margin of 100% (two-sided 95% CI: - 0.24-0.31, upper limit of the 95% CI: 1.12) for number of punctures. Non-inferiority was not shown for needle and guidewire visibility and anatomic visibility.

CONCLUSION

PUDs for internal jugular venipuncture are not inferior to SUDs with regard to puncture time and number of punctures, despite differences in visibility and device performance.

The intranasal dexmedetomidine plus ketamine for procedural sedation in children, adaptive randomized controlled non-inferiority multicenter trial (Ketodex): a statistical analysis plan

Background

Procedural sedation and analgesia (PSA) is frequently required to perform closed reductions for fractures and dislocations in children. Intravenous (IV) ketamine is the most commonly used sedative agent for closed reductions. However, as children find IV insertion a distressing and painful procedure, there is need to identify a feasible alternative route of administration. There is evidence that a combination of dexmedetomidine and ketamine (ketodex), administered intranasally (IN), could provide adequate sedation for closed reductions while avoiding the need for IV insertion. However, there is uncertainty about the optimal combination dose for the two agents and whether it can provide adequate sedation for closed reductions. The Intranasal Dexmedetomidine Plus Ketamine for Procedural Sedation (Ketodex) study is a Bayesian phase II/III, non-inferiority trial in children undergoing PSA for closed reductions that aims to address both these research questions. This article presents in detail the statistical analysis plan for the Ketodex trial and was submitted before the outcomes of the trial were available for analysis.

Methods/design

The Ketodex trial is a multicenter, four-armed, randomized, double-dummy controlled, Bayesian response adaptive dose finding, non-inferiority, phase II/III trial designed to determine (i) whether IN ketodex is non-inferior to IV ketamine for adequate sedation in children undergoing a closed reduction of a fracture or dislocation in a pediatric emergency department and (ii) the combination dose for IN ketodex that provides optimal sedation. Adequate sedation will be primarily measured using the Pediatric Sedation State Scale. As secondary outcomes, the Ketodex trial will compare the length of stay in the emergency department, time to wakening, and adverse events between study arms.

Discussion

The Ketodex trial will provide evidence on the optimal dose for, and effectiveness of, IN ketodex as an alternative to IV ketamine providing sedation for patients undergoing a closed reduction. The data from the Ketodex trial will be analyzed from a Bayesian perspective according to this statistical analysis plan. This will reduce the risk of producing data-driven results introducing bias in our reported outcomes.

Trial registration

ClinicalTrials.gov NCT04195256. Registered on December 11, 2019.

Etifoxine is non-inferior than clonazepam for reduction of anxiety symptoms in the treatment of anxiety disorders: a randomized, double blind, non-inferiority trial

OBJECTIVE

To determine whether etifoxine, a non-benzodiazepine drug of the benzoxazine family, is non-inferior compared with clonazepam in the treatment of anxiety disorders.

METHOD

A randomized controlled double blind trial with parallel groups was conducted. A total of 179 volunteer patients with a diagnosis of anxiety disorder (DSM-IV), between 18 and 64 years of age, participated in this study. The experimental group received 150 mg/day of etifoxine and the control 1 mg/day of clonazepam, both in three daily doses for 12 weeks. This treatment was completed by 87 participants, and 70 were available for follow-up at 24 weeks from start of treatment. The primary objective was a non-inferiority comparison between etifoxine and clonazepam in the decrease of anxiety symptoms (HAM-A) at 12 weeks of treatment. Secondary outcomes included the evaluation of medication side effects (UKU), anxiety symptoms at 24 weeks of treatment, and clinical improvement (CGI). Data analysis included multiple imputation of missing data. The effect of etifoxine on the HAM-A, UKU, and CGI was evaluated with the intention of treatment, and a sensitivity analysis of the results was conducted. Non-inferiority would be declared by a standardized mean difference (SMD) between clonazepam and etifoxine not superior to 0.31 in favour of clonazepam.

RESULTS

Using imputed data, etifoxine shows non-inferiority to clonazepam on the reduction of anxiety symptoms at the 12-week (SMD = 0.407; 95% CI, 0.069, 0.746) and 24-week follow-ups (SMD = 0.484; 95% CI, 0.163, 0.806) and presented fewer side effects (SMD = 0.58; 95% CI, 0.287, 0.889). LOCF analysis shows that etifoxine is non-inferior to clonazepam on reduction of anxiety symptoms and adverse symptoms even when no change was assigned as result to participant whom withdrew. Non-inferiority could be declared for clinical improvement (SMD = 0.326; 95% CI, - 0.20, 0.858).

CONCLUSION

Etifoxine was non-inferior to clonazepam on reduction of anxiety symptoms, adverse effects, and clinical improvement.

Hypofractionated radiation therapy comparing a standard radiotherapy schedule (over 3 weeks) with a novel 1-week schedule in adjuvant breast cancer: an open-label randomized controlled study (HYPORT-Adjuvant)-study protocol for a multicentre, randomized phase III trial

Background

Hypofractionated radiotherapy is the current standard for adjuvant radiotherapy across many centres. Further hypofractionation may be possible but remains to be investigated in non-Caucasian populations with more advanced disease, with a higher proportion of patients requiring mastectomy as well as tumour bed boost. We are reporting the design of randomized controlled trial testing the hypothesis that a 1-week (5 fractions) regimen of radiotherapy will be non-inferior to a standard 3-week (15 fractions) schedule.

Methods

We describe a multicentre, randomized controlled trial recruiting patients at large academic centres across India. Patients without distant metastases who merit adjuvant radiotherapy will be eligible for inclusion in the study. Patients in the control arm will receive adjuvant radiotherapy to the breast or chest wall (with/without regional nodes) to a dose of 40 Gy/15 fractions/3 weeks, while those in the experimental arm will receive a dose of 26 Gy/5 fractions/1 week (to the same volume). The use of a simultaneous integrated boost (dose of 8 Gy and 6 Gy, respectively) is allowed in patients who have undergone breast conservation. A sample size of 2100 patients provides an 80% power to detect a non-inferiority of 3% in the 5-year locoregional recurrence rate with a one-sided type I error of 2.5%, assuming that the locoregional recurrence rate in the control arm is 5% at 5 years (corresponding to a hazard ratio of 1.63). Patients will be recruited over a period of 5 years and followed up for a further 5 years thereafter.

Discussion

If a five-fraction regimen of breast cancer is proven to be non-inferior, this will result in a significant improvement in the access to radiotherapy, as well as reduced costs of treatment. The trial gives an opportunity to standardize and quality-assure radiotherapy practices across the nation at the same time. Along with the results of the FAST-Forward trial, the safety of this intervention in advanced node-positive disease requiring regional nodal radiation will be established.

Trial registration

The trial has been registered at the Clinical Trial Registry of India (CTRI) vide registration number: CTRI/2018/12/016816 (December 31, 2018) as well as the ClinicalTrial.gov website at NCT03788213 (December 28, 2018).

Efficacy and safety of generic exenatide injection in Chinese patients with type 2 diabetes: a multicenter, randomized, controlled, non-inferiority trial

AIMS

This study aimed to compare the efficacy and safety of generic exenatide with branded exenatide Byetta^® in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled on monotherapy or combination therapy of metformin and insulin secretagogues.

METHODS

A multicenter, randomized, controlled, non-inferiority trial was performed. A total of 240 patients with T2DM and glycated hemoglobin (HbA1c) ≥ 7% (53 mmol/mol) to ≤ 9.0% (75 mmol/mol) on monotherapy or combination therapy of metformin and insulin secretagogues for at least 3 months were randomized into generic exenatide or branded exenatide groups with a 1:1 ratio for 16 weeks of treatment. The primary endpoint was the change in HbA1c levels from baseline at week 16, with a non-inferiority margin of - 0.35% (- 3.83 mmol/mol) (lower bound of one-sided 95% confidence interval (CI) > - 0.35% (- 3.83 mmol/mol)). Secondary endpoints included the proportion of participants achieving HbA1c < 7% (53 mmol/mol), the changes in fasting plasma glucose (FPG), 2-h postprandial glucose (2hPG) following a standard meal, 7-point self-monitoring blood glucose (SMBG) profiles, body weight change from baseline at week 16 and the change in HbA1c levels from baseline at week 8. Safety issues were also evaluated.

RESULTS

After 16 weeks of treatment, HbA1c levels decreased significantly from baseline in the two groups, with a reduction of - 1.10% ± 1.31% (- 12.0 mmol/mol ± 14.3 mmol/mol) in the generic exenatide group and - 1.08% ± 1.11% (- 11.8 mmol/mol ± 12.1 mmol/mol) in the branded exenatide group (both P < 0.001). The least-squares mean difference of HbA1c reduction between the two groups was - 0.03% (- 0.33 mmol/mol), with a lower one-sided 95% CI limit of - 0.27% (- 2.95 mmol/mol), which was higher than the prespecified non-inferiority margin of - 0.35% (- 3.83 mmol/mol). Moreover, there were no significant differences in the proportion of participants achieving HbA1c < 7% (53 mmol/mol) and the changes in FPG, 2hPG, 7-point SMBG profiles and body weight at week 16 and the change in HbA1c levels from baseline at week 8 (all P > 0.05) between the two groups. The incidence of adverse events, including the incidence of hypoglycemia (18.3% and 17.5%, respectively), was similar for the generic and branded exenatide groups (P > 0.05).

CONCLUSIONS

In patients with T2DM inadequately controlled on monotherapy or combination therapy of metformin and insulin secretagogues, add-on treatment with generic exenatide demonstrated non-inferiority to branded exenatide in terms of improvements in HbA1c after 16 weeks of treatment. Furthermore, the two drugs were also similar for other efficacy endpoints and safety profile. Trial registration Chinese Clinical Trial Registry: ChiCTR-IPR-15006558, Date registered May 27, 2015.

Internet-based psychodynamic versus cognitive behaviour therapy for adolescents with depression: study protocol for a non-inferiority randomized controlled trial (the ERiCA study)

Background

Adolescent depression is a common mental health problem and there is an urgent need for effective and accessible treatments. Internet-based interventions solve many obstacles for seeking and receiving treatment, thus increasing access to effective treatments. Internet-based cognitive behavioural therapy (ICBT) for adolescent depression has demonstrated efficacy in previous trials. In order to broaden the range of evidence-based treatments for young people, we evaluated a newly developed affect-focused Internet-based psychodynamic treatment (IPDT) in a previous study with promising results. The purpose of the planned study is to evaluate the efficacy of IPDT for adolescent depression in a non-inferiority trial, comparing it to ICBT.

Methods

The study will employ a parallel randomized non-inferiority design (ratio 1:1; n = 270). Eligible participants are adolescents 15–19 years suffering from depression. The primary hypothesis is that IPDT will be non-inferior to ICBT in reducing depressive symptoms from pre-treatment to end of treatment. Secondary research questions include comparing outcomes of IPDT and ICBT regarding anxiety symptoms, emotion regulation and self-compassion. Additional data will be collected to evaluate cost-effectiveness as well as investigating predictors, moderators and mediators of outcome. In addition, we will examine long-term outcome up to 1 year after end of treatment. Diagnostic interviews with MINI 7.0 will be used to establish primary diagnosis of depression as well as ruling out any exclusion criteria. Both treatments consist of eight modules over 10 weeks, complemented with therapist support through text messages and weekly chat sessions. Primary outcome measure is the Quick Inventory of Depressive Symptomatology in Adolescents Self-Rated (QIDS-A17-SR). Primary outcome will be analysed using data from all participants entering the study using a multilevel growth curve strategy based on the weekly measurements of QIDS-A17-SR. The non-inferiority margin is defined as d = 0.30.

Discussion

This trial will demonstrate whether IPDT is non-inferior to ICBT in the treatment of adolescent depression. The study might therefore broaden the range of evidence-based treatment alternatives for young people struggling with depression. Further analyses of data from this trial may increase our knowledge about “what works for whom” and the pathways of change for two distinct types of interventions.

Trial registration

ISRCTN12552584, Registered on 13 August 2019.

Determining a Bayesian predictive power stopping rule for futility in a non-inferiority trial with binary outcomes

Background/Aims

Non-inferiority trials investigate whether a novel intervention, which typically has other benefits (i.e., cheaper or safer), has similar clinical effectiveness to currently available treatments. In situations where interim evidence in a non-inferiority trial suggests that the novel treatment is truly inferior, ethical concerns with continuing randomisation to the “inferior” intervention are raised. Thus, if interim data indicate that concluding non-inferiority at the end of the trial is unlikely, stopping for futility should be considered. To date, limited examples are available to guide the development of stopping rules for non-inferiority trials.

Methods

We used a Bayesian predictive power approach to develop a stopping rule for futility for a trial collecting binary outcomes. We evaluated the frequentist operating characteristics of the stopping rule to ensure control of the Type I and Type II error. Our case study is the Intranasal Ketamine for Procedural Sedation trial (INK trial), a non-inferiority trial designed to assess the sedative properties of ketamine administered using two alternative routes.

Results

We considered implementing our stopping rule after the INK trial enrols 140 patients out of 560. The trial would be stopped if 12 more patients experience a failure on the novel treatment compared to standard care. This trial has a type I error rate of 2.2% and a power of 80%.

Conclusions

Stopping for futility in non-inferiority trials reduces exposure to ineffective treatments and preserves resources for alternative research questions. Futility stopping rules based on Bayesian predictive power are easy to implement and align with trial aims.

Trial registration

ClinicalTrials.gov NCT02828566 July 11, 2016.

•

It is important to consider stopping for futility in non-inferiority trials.

•

We develop a rule to stop a non-inferiority trial using Bayesian predictive power.

•

We provide code and an online application to implement this method.

•

We reduce the complexity of developing stopping rules in non-inferiority trials.

Placebo-To be or not to be? Are there really alternatives to placebo-controlled trials?

Recent success of established treatment has driven concerns about the ethics of using placebo-controlled trials in psychiatry. Active-controlled (superiority or non-inferiority) trials do not include a placebo-arm and thus avoid the associated ethical concerns but show disadvantages in other respects. The aim of this paper is to review the available literature and critically discuss the evidence regarding the use of placebo-controlled- versus active-controlled trials. A MEDLINE/PubMed and Google Scholar search was performed. Studies included focused on the deliberation on placebo-controlled- versus active-controlled trials. Twenty-six studies were included. The most cited benefits of placebo-controlled trials were greater scientific reliability of the results and no average impact on patients' health. Disadvantages were mainly related to withholding effective treatment and limited generalizability. The most frequent argument in favor of active-controlled trials is the lower chance of receiving ineffective medication during the trial. Downsides include larger sample sizes, higher costs and lower scientific reliability of results. Most authors agree that all trial designs are relevant to psychiatric research depending on study goals. Whatsoever, data does not support forgoing placebo-controlled trials. Expert consensus is warranted to permit drawing conclusions on the debate on the relevance of placebo-controlled trials.

Systematic review and meta-analysis to estimate the antibacterial treatment effect of nitrofurantoin for a non-inferiority trial in uncomplicated urinary tract infection

OBJECTIVES

Active-comparator, non-inferiority study designs are used in uncomplicated urinary tract infection (uUTI) to establish the efficacy of a new antibacterial, given the availability of effective antibiotics. Here we estimated the treatment effect of a planned antimicrobial comparator (nitrofurantoin) from historical trial data to properly design an upcoming non-inferiority trial in uUTI.

METHODS

A systematic literature review and meta-analysis was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, which incorporate recommendations for standardised data quality assessment, reporting of results, risk of bias assessment and sensitivity analyses. To account for interstudy variability, a weighted, non-iterative, random-effects model was fit using R software to obtain estimates of the microbiological response rate and corresponding 95% confidence interval (CI) for nitrofurantoin and placebo treatment. Interstudy heterogeneity was assessed with Cochran's χ² test for interstudy heterogeneity; I² statistic and P-values were computed and included in the forest plot of the meta-analysis.

RESULTS

Twelve unique studies met the final eligibility criteria for meta-analysis inclusion; three trials assessed placebo efficacy, eight trials assessed nitrofurantoin efficacy, and one study assessed both nitrofurantoin and placebo efficacy in uUTI. The overall microbiological response (95% CI) was 0.766 (0.665-0.867) for nitrofurantoin and 0.342 (0.288-0.397) for placebo.

CONCLUSION

The corresponding treatment effect estimate for nitrofurantoin was 26.8%, which supports a conservative non-inferiority margin of 12.5% and is consistent with the recently published draft FDA guidance. The findings from this systematic review and meta-analysis may inform future antibacterial trials by providing non-inferiority margin justification.

Testing non-inferiority of blended versus face-to-face cognitive behavioural therapy for severe fatigue in patients with multiple sclerosis and the effectiveness of blended booster sessions aimed at improving long-term outcome following both therapies: study protocol for two observer-blinded randomized clinical trials

BACKGROUND

Cognitive behavioural therapy (CBT) has been found to be effective in reducing fatigue severity in MS patients directly following treatment. However, long-term effects are inconsistent leaving room for improvement. In addition, individual face-to-face CBT draws heavily on limited treatment capacity, and the travel distance to the treatment centre can be burdensome for patients. Therefore, we developed "MS Fit", a blended CBT for MS-related fatigue, based on a face-to-face CBT protocol found effective in a previous study, and "MS Stay Fit", internet-based booster sessions to improve long-term effectiveness of CBT for MS-related fatigue. This article presents the protocol of two randomised clinical trials (RCTs) conducted within one study investigating (1) the non-inferiority of MS Fit compared with evidence-based face-to-face CBT for MS-related fatigue and (2) the effectiveness of MS Stay Fit on the long-term outcome of fatigue compared with no booster sessions.

METHODS/DESIGN

The first part of this study is an observer-blinded non-inferiority multicentre RCT, in which 166 severely fatigued MS patients will be randomly assigned (1:1 ratio, computer-generated sequence) to either face-to-face CBT or blended CBT (MS Fit) for fatigue. The primary endpoint is at 20 weeks after baseline. After this post-treatment assessment, patients will be randomly assigned again (1:1 ratio, computer generated sequence) to either MS Stay Fit consisting of two booster sessions at 2 and 4 months after end of treatment or no booster sessions. The primary endpoint of the second study is 52 weeks after baseline. Primary outcome measure in both studies is fatigue severity assessed with the fatigue severity subscale of the Checklist Individual Strength (CIS20r). Outcomes will be assessed at baseline (T0), at the end of treatment (T20), and after 39 and 52 weeks (T39 and T52).

DISCUSSION

If MS Fit is found to be non-inferior to face-to-face CBT, it will improve the accessibility of this treatment. In addition, the study aims to test whether it is possible to improve long-term effectiveness of CBT for MS-related fatigue with MS Stay Fit.

TRIAL REGISTRATION

Dutch Trial Register (NTR6966), registered 18 January 2018 https://www.trialregister.nl/trial/6782 WORLD HEALTH ORGANIZATION (WHO) TRIAL REGISTRATION DATA SET: All items from the WHO Trial Registration Data Set can be found within the protocol.

Non-inferiority trial comparing cigarette consumption, adoption rates, acceptability, tolerability, and tobacco harm reduction potential in smokers switching to Heated Tobacco Products or electronic cigarettes: Study protocol for a randomized controlled trial

Background

Despite the introduction of tobacco control measures, smoking remains highly prevalent in most EU countries. In Italy, one in four adults were still regular smokers in 2017. Increasing use of combustion-free delivering nicotine technologies for cigarette substitution may accelerate the current downward trends in smoking prevalence. Whether Heated Tobacco Products (HTPs) are more effective tobacco smoking substitutes that may potentially facilitate adoption and full conversion compared to e-cigarettes (ECs) is not known.

We have designed a prospective study to compare changes in cigarette consumption and adoption rates among smokers randomized to either HTPs or ECs. Product acceptability, tolerability, and their tobacco harm reduction potential will be also compared.

Methods

220 healthy smokers, not motivated to quit, will be randomized into a 12-weeks single-center, open label, non-inferiority trial comparing study outcomes from HTPs vs. ECs use. The primary outcome will be biochemically verified self-reported continuous abstinence at 12-weeks from the previous visit. Secondary outcomes will include: smoking reduction from baseline, adoption rates and product acceptability, tolerability, changes in step test values and in the level of selected biomarkers of exposure in exhaled breath (i.e. eCO) and in spot urine samples. A follow-up visit will be also included at 24-weeks to review product usage and smoking behavior under naturalistic condition of use.

Recruitment of participants started in May 2019 and enrolment is expected to be completed in November 2019.

Discussion

This will be the first study directly comparing Heated Tobacco Products with Electronic Cigarettes in term of reduction in cigarette consumption, adoption rates, product acceptability, tolerability, and tobacco harm reduction potential. This knowledge can contribute to a better understanding of the potential role of this new technology in the evolving nicotine consumer market.

Trial registration

ClinicalTrials.gov ID: NCT03569748.

Registered June 25, 2018.

https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=1&cx=-jg9qo4.

Effect of Extensive Ablation on Recurrence in Patients with Persistent Atrial Fibrillation Treated with Pulmonary Vein Isolation (EARNEST-PVI) trial: Design and rationale

BACKGROUND

Although extensive substrate modification in addition to pulmonary vein isolation (PVI) has been recommended in catheter ablation for persistent atrial fibrillation (AF), recent randomized controlled trials have not demonstrated efficacy of such additional ablations.

METHODS AND STUDY DESIGN

The Osaka Cardiovascular Conference will conduct a multicenter, randomized, open-label trial aiming to examine whether PVI alone is non-inferior to PVI plus additional ablation such as linear ablation and/or complex fractionated atrial electrogram ablation in patients with persistent AF. The primary outcome is recurrence of AF documented by scheduled or symptom-driven electrocardiogram tests during a 1-year follow-up period after the index ablation. The key secondary endpoints include all-cause death, occurrence of symptomatic stroke, complications related to the procedure, and quality of life assessment using the 36-item Short-Form Health Survey. The clinical impact of the presence or absence of AF trigger foci, and their origins in cases with them, on the results of catheter ablation will also be investigated as an exploratory endpoint. A total of 512 patients will be enrolled and followed up to 1 year.

CONCLUSIONS

The EARNEST-PVI trial is a randomized controlled trial designed to assess whether PVI alone is non-inferior to extended substrate ablation for patients with persistent AF undergoing a first catheter ablation.

Tranexamic Acid in Reducing Gross Hemorrhage and Transfusions of Spine Surgeries (TARGETS): study protocol for a prospective, randomized, double-blind, non-inferiority trial

BACKGROUND

Tranexamic acid (TXA) has been routinely delivered in multisegmental spinal decompression and bone graft fusion surgeries with satisfactory outcomes in minimizing gross blood loss and transfusion demands. However, concerns remain that intravenously delivered TXA (ivTXA) may increase risks of postoperative convulsive seizures and systemic thrombogenicity. Topical use of TXA (tTXA), being more targeted to the surgical bleeding site while minimizing patient systemic exposure to ivTXA, has been successfully applied to attenuate blood losses and transfusion requirements in hip and knee arthroplasty. Yet, randomized controlled trials on tTXA efficacy and safety are still lacking in spinal surgeries. With this knowledge gap, we hypothesize that tTXA exhibits non-inferiority to ivTXA in blood conservation and clinical safety in multisegmental spinal decompression and bone graft fusion surgeries.

METHODS

A prospective, randomized, double-blind, non-inferiority study design will be adopted. The target sample size is 176. Eligible patients will be randomly allocated to receive either ivTXA or tTXA treatment. The primary end point is the perioperative total blood loss. Secondary end points consist of visible blood losses (intraoperative, postoperative 0-24 h, postoperative 0-48 h, combined perioperative blood loss, total postoperative blood loss), postoperative hidden blood loss, plasma TXA levels, postoperative conventional coagulation monitoring (prothrombin time, activated partial thromboplastin time, fiber Bragg grating, international normalized ratio), postoperative thromboelastography monitoring (reaction time, clot formation time, clot strength, fibrinolysis), postoperative hemoglobin nadir (within postoperative 48 h), perioperative transfusion amounts and rates, and length of hospital stay. Safety end points will be monitored too.

DISCUSSION

This proposed study will contribute to expanding clinical evidences of tTXA for bleeding management in major spinal surgeries. This will be a high-quality prospective randomized trial with sufficient sample size, strict methodology, and few design deficits. It will investigate the potentiality of tTXA as an alternative to ivTXA in improving the current standard of care in multisegmental spinal surgeries, thereby optimizing the enhanced recovery after surgery scheme in spinal surgeries.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03011866 . Registered on 5 January 2017.

Evidence-based sizing of non-inferiority trials using decision models

Background

There are significant challenges to the successful conduct of non-inferiority trials because they require large numbers to demonstrate that an alternative intervention is “not too much worse” than the standard. In this paper, we present a novel strategy for designing non-inferiority trials using an approach for determining the appropriate non-inferiority margin (δ), which explicitly balances the benefits of interventions in the two arms of the study (e.g. lower recurrence rate or better survival) with the burden of interventions (e.g. toxicity, pain), and early and late-term morbidity.

Methods

We use a decision analytic approach to simulate a trial using a fixed value for the trial outcome of interest (e.g. cancer incidence or recurrence) under the standard intervention (p_S) and systematically varying the incidence of the outcome in the alternative intervention (p_A). The non-inferiority margin, p_A – p_S = δ, is reached when the lower event rate of the standard therapy counterbalances the higher event rate but improved morbidity burden of the alternative. We consider the appropriate non-inferiority margin as the tipping point at which the quality-adjusted life-years saved in the two arms are equal.

Results

Using the European Polyp Surveillance non-inferiority trial as an example, our decision analytic approach suggests an appropriate non-inferiority margin, defined here as the difference between the two study arms in the 10-year risk of being diagnosed with colorectal cancer, of 0.42% rather than the 0.50% used to design the trial. The size of the non-inferiority margin was smaller for higher assumed burden of colonoscopies.

Conclusions

The example demonstrates that applying our proposed method appears feasible in real-world settings and offers the benefits of more explicit and rigorous quantification of the various considerations relevant for determining a non-inferiority margin and associated trial sample size.

Clinical pharmacodynamics and long-term efficacy of Talcom vs. Plavix in patients undergoing coronary stent implantation: a randomized study with 5-year follow-up

PURPOSE

Form II clopidogrel bisulfate (Plavix) has been extensively used in patients with acute coronary syndrome. However, the efficacy of form I clopidogrel bisulfate (Talcom) was less investigated. The aim of this study was to investigate the efficacy and safety of Talcom compared with Plavix.

METHOD

Two hundred and forty-eight patients were recruited after receiving percutaneous coronary intervention (PCI). Participants were randomly assigned to Talcom or Plavix group, and administered with Talcom or Plavix 75 mg od respectively in combination with aspirin 100 mg od for 12 months. Primary endpoints were set as levels of adenosine diphosphate-induced platelet aggregation (PL_ADP) on the 5th day and at 1 month after randomization. Patients were followed-up for 5 years. Bleeding events and major adverse cardiovascular events (MACE) including cardiac death, non-fatal myocardial infarction, ischemic stroke, target lesion revascularization (TLR), and cardiogenic re-admission were recorded.

RESULTS

On the 5th day and at 1 month after randomization, the antiplatelet effect of Talcom was non-inferior to that of Plavix [PL_ADP (5th day): 30% (22%, 43%) vs. 33% (22%, 44%), p = 0.007; PL_ADP (1 month): 29% (19%, 43%) vs. 31% (22%, 43%), p = 0.005]. A total of 208 patients completed the follow-up, the incidences of MACE and bleeding were both comparable, and the MACE-free survival did not differ between the two groups. However, the expenditure was 32% lower for Talcom compared to Plavix during the treatment period.

CONCLUSIONS

The antiplatelet effect of Talcom is non-inferior to Plavix, and the clinical efficacy and safety of Talcom and Plavix at 5 years were not significantly different in this study.

Design and statistical considerations for studies evaluating the efficacy of a single dose of the human papillomavirus (HPV) vaccine

Cervical cancer is a leading cause of cancer mortality in women worldwide. Human papillomavirus (HPV) types 16 and 18 cause about 70% of all cervical cancers. Clinical trials have demonstrated that three doses of either commercially available HPV vaccine, Cervarix ® or Gardasil ®, prevent most new HPV 16/18 infections and associated precancerous lesions. Based on evidence of immunological non-inferiority, 2-dose regimens have been licensed for adolescents in the United States, European Union, and elsewhere. However, if a single dose were effective, vaccine costs would be reduced substantially and the logistics of vaccination would be greatly simplified, enabling vaccination programs in developing countries. The National Cancer Institute (NCI) and the Agencia Costarricense de Investigaciones Biomédicas (ACIB) are conducting, with support from the Bill & Melinda Gates Foundation and the International Agency for Research on Cancer (IARC), a large 24,000 girl study to evaluate the efficacy of a 1-dose regimen. The first component of the study is a four-year non-inferiority trial comparing 1- to 2-dose regimens of the two licensed vaccines. The second component is an observational study that estimates the vaccine efficacy (VE) of each regimen by comparing the HPV infection rates in the trial arms to those in a contemporaneous survey group of unvaccinated girls. In this paper, we describe the design and statistical analysis for this study. We explain the advantage of defining non-inferiority on the absolute risk scale when the expected event rate is near 0 and, given this definition, suggest an approach to account for missing clinic visits. We then describe the problem of estimating VE in the absence of a randomized placebo arm and offer our solution.

The Impact of the Underlying Risk in Control Group and Effect Measures in Non-Inferiority Trials With Time-to-Event Data: A Simulation Study

Background

We designed a simulation study to assess how the conclusions of a non-inferiority trial (NIT) will change if the observed risk is different from the expected risk.

Methods

We simulated Weibull distribution time-to-event data with a true hazard ratio (HR) being equal or close to 1. The empirical margins and sample size of a hypothetical trial were chosen based on a systematic review. Setting the significance level at 5% for the two-sided confidence interval (CI), we examined the statistical power (i.e., the probabilities of the upper limit of the 95% CI falling within the margin) of using two measures at various underlying risk in the control group.

Results

Using the empirical margins, HRs of 1.2, 1.35 or 1.5, the statistical power is lower than 0.22 when the underlying risk in the control group is less than 10%, but the power increases along with the higher underlying risk. The predicted upper limit of the 95% CI of the difference in two Kaplan-Meier estimators (DTKME) is low when risk is low (< 20%) or high (> 80%), but reaches the highest value when risk is around 50%. When the underlying risk in the control group is lower than 10%, measures of DTKME resulted in much higher power than HR.

Conclusions

When HR is the effect measure, the probability of concluding non-inferiority will increase as the underlying risk in the control group increases. When DTKME is the effect measure, the probability of concluding non-inferiority will decrease as the underlying risk in the control increases. In this case, the probability of concluding non-inferiority is at a minimum when the control risk reaches about 50%. When the risk in the control arm is less than 10%, the conclusion of an NIT is sensitive to the choice of effect measure.

Dual Bronchodilation with Indacaterol Maleate/Glycopyrronium Bromide Compared with Umeclidinium Bromide/Vilanterol in Patients with Moderate-to-Severe COPD: Results from Two Randomized, Controlled, Cross-over Studies

PURPOSE

To compare the efficacy and safety of two long-acting dual bronchodilator combinations: indacaterol/glycopyrrolate (IND/GLY) versus umeclidinium/vilanterol (UMEC/VI).

METHODS

Studies A2349 and A2350 were replicate, randomized, double-blind, double-dummy, active-controlled, cross-over studies in patients with moderate-to-severe COPD. Patients were randomized to sequential 12-week treatments of twice-daily IND/GLY 27.5/15.6 μg and once-daily UMEC/VI 62.5/25 μg, each separated by a 3-week washout. The primary objective was to demonstrate non-inferiority of IND/GLY compared with UMEC/VI in terms of the 24-h forced expiratory volume in 1 s profile at week 12 (FEV₁ AUC_0-24). Rescue medication use, symptom control, and safety were assessed throughout.

RESULTS

Both treatments delivered substantial bronchodilation over 12 weeks, with improvements in FEV₁ AUC_0-24h at week 12 of 232 and 185 mL for IND/GLY, and 244 and 203 mL with UMEC/VI in Studies A2349 and A2350, respectively. The primary efficacy objective of non-inferiority of IND/GLY relative to UMEC/VI was not met as the lower bound of the confidence interval for the LS treatment comparison was below the pre-specified non-inferiority margin of -20 mL in both studies: -26.9 and -34.2 mL, respectively (LS mean between-treatment differences: -11.5 and -18.2 mL). Both drugs were well tolerated, with AE profiles consistent with their respective prescribing information.

CONCLUSIONS

IND/GLY and UMEC/VI provided clinically meaningful and comparable bronchodilation. Non-inferiority of IND/GLY to UMEC/VI could not be declared although between-treatment differences were not clinically relevant. The data support the use of IND/GLY as an efficacious and well tolerated treatment option in patients with COPD. (ClinicalTrials.gov NCT02487446 and NCT02487498).

Statistical analysis plan for the Urodynamics for Prostate Surgery Trial; Randomised Evaluation of Assessment Methods (UPSTREAM)

BACKGROUND

Current management for men with lower urinary tract symptoms (LUTS) is a pathway that results in prostate surgery in a significant proportion. While helpful in relieving benign prostatic obstruction (BPO), surgery may be ineffective for men suffering from difficulties not relating to BPO. The UPSTREAM trial started recruitment in October 2014 with the aim of establishing whether a care pathway including urodynamics (a diagnostic tool for BPO and thus an indication of whether surgery is needed) is no worse for men, in terms of symptomatic outcome, than one without (routine care).

METHODS/DESIGN

This analysis plan outlines the main outcomes of the study and specific design choices, such as non-inferiority margins. The trial is currently recruiting in 26 hospitals across the UK, randomising men to either urodynamics or routine care, with recruitment set to end on the 31 December 2016. All outcomes will be measured 18 months after randomisation to allow sufficient time for surgical procedures and recovery. The primary outcome is based on a non-inferiority design with a margin of 1 point on the International Prostate Symptom Score (IPSS) scale. The key secondary outcome for this trial is surgery rate per arm, which is estimated to be at least 18% lower in the urodynamics arm. Surgery rates, adverse events, flow rate, urinary symptoms and sexual symptoms are secondary outcomes to be assessed for superiority. This is an update to the UPSTREAM protocol, which has already been published in this journal.

DISCUSSION

This a priori statistical analysis plan aims to reduce reporting bias by allowing access to the trial's objectives and plans in advance of recruitment end. The results of the trial are expected to be published soon after the trial end date of 30 September 2018.

TRIAL REGISTRATION

ISRCTN registry, ISRCTN56164274 . Registered on 8 April 2014.

Comparative study of the efficacy of transdermal buprenorphine patches and prolonged-release tramadol tablets for postoperative pain control after spinal fusion surgery: a prospective, randomized controlled non-inferiority trial

PURPOSE

To compare the efficacy of a transdermal buprenorphine patch (5, 10, 15, and 20 μg/h) with that of oral tramadol (150, 200, 250, and 300 mg) for postoperative pain control after single level spinal fusion surgery.

METHODS

The present study (ClinicalTrials.gov, number NCT02416804) was a prospective, randomized controlled non-inferiority trial designed to determine the efficacy of buprenorphine TDS for alleviating postoperative pain following patient controlled analgesia (PCA) in persons underwent a single level posterior lumbar interbody fusion surgery through 1:1 allocation. The primary outcome was the Visual Analog Pain Scale (VAS) score for postoperative back pain at 7 days after surgery. The non-inferior margin of the VAS was set at δ = 1.5 points.

RESULTS

The VAS score (primary outcome) for postoperative back pain at 7 days after surgery in the Buprenorphine group was not inferior compared to the Tramadol group. The overall changes in VAS scores for postoperative pain during follow-up assessments over a 2-week period did not differ between both groups. However, the VAS scores for postoperative pain significantly improved with time after surgery in both groups. The patterns of changes in the VAS scores for postoperative pain during the follow-up period were not significantly different between the both groups.

CONCLUSIONS

The efficacy of buprenorphine TDS was not inferior to that of oral tramadol medication for alleviating postoperative pain in the subacute period from 72 h after surgery, following PCA administration. In addition, adverse events were similar between both groups.

Guided Internet-based versus face-to-face clinical care in the management of tinnitus: study protocol for a multi-centre randomised controlled trial

Background

Innovative strategies are required to improve access to evidence-based tinnitus interventions. A guided Internet-based cognitive behavioural therapy (iCBT) intervention for tinnitus was therefore developed for a U.K. population. Initial clinical trials indicated efficacy of iCBT at reducing tinnitus severity and associated comorbidities such as insomnia and depression. The aim of this phase III randomised controlled trial is to compare this new iCBT intervention with an established intervention, namely face-to-face clinical care for tinnitus.

Methods/design

This will be a multi-centre study undertaken across three hospitals in the East of England. The design is a randomised, two-arm, parallel-group, non-inferiority trial with a 2-month follow-up. The experimental group will receive the guided iCBT intervention, whereas the active control group will receive the usual face-to-face clinical care. An independent researcher will randomly assign participants, using a computer-generated randomisation schedule, after stratification for tinnitus severity. There will be 46 participants in each group. The primary assessment measure will be the Tinnitus Functional Index. Data analysis will establish whether non-inferiority is achieved using a pre-defined non-inferiority margin.

Discussion

This protocol outlines phase III of a clinical trial comparing a new iCBT with established face-to-face care for tinnitus. If guided iCBT for tinnitus proves to be as effective as the usual tinnitus care, it may be a viable additional management route for individuals with tinnitus. This could increase access to evidence-based effective tinnitus care and reduce the pressures on existing health care systems.

Trial registration

ClinicalTrials.gov identifier: NCT02665975. Registered on 22 January 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1931-6) contains supplementary material, which is available to authorized users.

A pragmatic randomised controlled trial assessing the non-inferiority of counselling for depression versus cognitive-behaviour therapy for patients in primary care meeting a diagnosis of moderate or severe depression (PRaCTICED): Study protocol for a randomised controlled trial

BACKGROUND

NICE guidelines state cognitive behavioural therapy (CBT) is a front-line psychological treatment for people presenting with depression in primary care. Counselling for Depression (CfD), a form of Person-Centred Experiential therapy, is also offered within Improving Access to Psychological Therapies (IAPT) services for moderate depression but its effectiveness for severe depression has not been investigated. A full-scale randomised controlled trial to determine the efficacy and cost-effectiveness of CfD is required.

METHODS

PRaCTICED is a two-arm, parallel group, non-inferiority randomised controlled trial comparing CfD against CBT. It is embedded within the local IAPT service using a stepped care service delivery model where CBT and CfD are routinely offered at step 3. Trial inclusion criteria comprise patients aged 18 years or over, wishing to work on their depression, judged to require a step 3 intervention, and meeting an ICD-10 diagnosis of moderate or severe depression. Patients are randomised using a centralised, web-based system to CfD or CBT with each treatment being delivered up to a maximum 20 sessions. Both interventions are manualised with treatment fidelity tested via supervision and random sampling of sessions using adherence/competency scales. The primary outcome measure is the Patient Health Questionnaire-9 collected at baseline, 6 and 12 months. Secondary outcome measures tap depression, generic psychological distress, anxiety, functioning and quality of life. Cost-effectiveness is determined by a patient service receipt questionnaire. Exit interviews are conducted with patients by research assessors blind to treatment allocation. The trial requires 500 patients (250 per arm) to test the non-inferiority hypothesis of -2 PHQ-9 points at the one-sided, 2.5% significance level with 90% power, assuming no underlying difference and a standard deviation of 6.9. The primary analysis will be undertaken on all patients randomised (intent to treat) alongside per-protocol and complier-average causal effect analyses as recommended by the extension to the CONSORT statement for non-inferiority trials.

DISCUSSION

This large-scale trial utilises routinely collected outcome data as well as specific trial data to provide evidence of the comparative efficacy and cost-effectiveness of Counselling for Depression compared with Cognitive Behaviour Therapy as delivered within the UK government's Improving Access to Psychological Therapies initiative.

TRIAL REGISTRATION

Controlled Trials ISRCTN Registry, ISRCTN06461651 . Registered on 14 September 2014.

Treatment of complicated urinary tract infection and acute pyelonephritis by short-course intravenous levofloxacin (750 mg/day) or conventional intravenous/oral levofloxacin (500 mg/day): prospective, open-label, randomized, controlled, multicenter, non-inferiority clinical trial

Objective

To compare the efficacy and safety of short-course intravenous levofloxacin (LVFX) 750 mg with a conventional intravenous/oral regimen of LVFX 500 mg in patients from China with complicated urinary tract infections (cUTIs) and acute pyelonephritis (APN).

Methods

This was a prospective, open-label, randomized, controlled, multicenter, non-inferiority clinical trial. Patients with cUTI and APN were randomly assigned to a short-course therapy group (intravenous LVFX at750 mg/day for 5 days) or a conventional therapy group (intravenous/oral regimen of LVFX at 500 mg/day for 7–14 days). The clinical, laboratory, and microbiological results were evaluated for efficacy and safety.

Results

The median dose of LVFX was 3555.4 mg in the short-course therapy group and 4874.2 mg in the conventional therapy group. Intention-to-treat analysis indicated the clinical effectiveness in the short-course therapy group (89.87%, 142/158) was non-inferior to that in the conventional therapy group (89.31%, 142/159). The microbiological effectiveness rates were also similar (short-course therapy: 89.55%, 60/67; conventional therapy: 86.30%, 63/73; p > 0.05). There were no significant differences in other parameters, including clinical and microbiological recurrence rates. The incidence of adverse effects and drug-related adverse effects were also similar for the short-course therapy group (21.95%, 36/164; 18.90%, 31/164) and the conventional therapy group (23.03%, 38/165; 15.76%, 26/165).

Conclusion

Patients with cUTIs and APN who were given short-course LVFX therapy and conventional LVFX therapy had similar outcomes in clinical and microbiological efficacy, tolerance, and safety. The short-course therapy described here is a more convenient alternative to the conventional regimen with potential implication in anti-resistance and cost saving.

Electronic supplementary material

The online version of this article (doi:10.1007/s11255-017-1507-0) contains supplementary material, which is available to authorized users.

Stereotactic radiotherapy of the tumor bed compared to whole brain radiotherapy after surgery of single brain metastasis: Results from a randomized trial

PURPOSE

To evaluate if neurological/cognitive function outcomes in patients with resected single brain metastasis (BM) after stereotactic radiotherapy of the tumor bed (SRT-TB) are not inferior compared to those achieved with whole-brain radiotherapy (WBRT).

METHODS

Patients with total/subtotal resection of single BM were randomly assigned either to SRT-TB (n=29) or WBRT (n=30). SRT-TB arm consisted of 15Gy/1 fraction, or 5×5Gy. WBRT consisted of 30Gy/10 fractions. Neurological/cognitive failure was defined as a decrease of neurological score by one point or more, or a worsening of the MiniMental test by at least 3 points, or neurological death. Cumulative incidence of neurological/cognitive failure (CINCF), neurological death (CIND), and overall survival (OS) were compared.

RESULTS

Median follow-up was 29months (range: 8-45) for 15 patients still alive. The difference in the probability of CINCF at 6months (primary endpoint) was -8% in favor of WBRT (95% confidence interval: +17% -35%; non-inferiority margin: -20%). In the intention-to-treat analysis, two-year CIND rates were 66% vs. 31%, for SRT-TB and WBRT arm, respectively, p=.015. The corresponding figures for OS were 10% vs. 37%, p=.046.

CONCLUSIONS

Non-inferiority of SRT-TB was not demonstrated in our underpowered study. More data from randomized studies are needed for confirmation of the value of this method.

Thermotolerance of an inactivated rabies vaccine for dogs

This study provides the first robust data that the antibody response of dogs vaccinated with Nobivac® Rabies vaccine stored for several months at high temperatures (up to 30°C) is not inferior to that of dogs vaccinated with vaccine stored under recommended cold-chain conditions (2-8°C). A controlled and randomized non-inferiority study was carried out comparing the four-week post vaccination serological responses of Tanzanian village dogs inoculated with vaccine which had been stored at elevated temperatures for different periods of time with those of dogs vaccinated with the same product stored according to label recommendations. Specifically, the neutralizing antibody response following the use of vaccine which had been stored for up to six months at 25°C or for three months at 30°C was not inferior to that following the use of cold-chain stored vaccine. These findings provide reassurance that the vaccine is likely to remain efficacious even if exposed to elevated temperatures for limited periods of time and, under these circumstances, it can safely be used and not necessarily destroyed or discarded. The availability of thermotolerant vaccines has been an important factor in the success of several disease control and elimination programs and could greatly increase the capacity of rabies vaccination campaigns to access hard to reach communities in Africa and Asia. We have not confirmed a 3-year duration of immunity for the high temperature stored vaccine, however because annual re-vaccination is usually practiced for dogs presented for vaccination during campaigns in Africa and Asia this should not be a cause for concern. These findings will provide confidence that, for rabies control and elimination programs using this vaccine in low-income settings, more flexible delivery models could be explored, including those that involve limited periods of transportation and storage at temperatures higher than that currently recommended.

Stability is maintained in adults with Gaucher disease type 1 switched from velaglucerase alfa to eliglustat or imiglucerase: A sub-analysis of the eliglustat ENCORE trial

Gaucher disease type 1 is an autosomal recessive disorder caused by deficient activity of the lysosomal enzyme acid β-glucosidase resulting in accumulation of glucosylceramide and clinical manifestations of anemia, thrombocytopenia, hepatosplenomegaly, and skeletal disease. The historic standard of care is intravenous recombinant enzyme therapy with imiglucerase. Eliglustat, an oral substrate reduction therapy, is a first-line treatment for adults with Gaucher disease type 1 who have a compatible CYP2D6-metabolizer phenotype (≈ 95% of patients). The 12-month ENCORE trial (NCT00943111) found eliglustat non-inferior to imiglucerase in maintaining stability in adult Gaucher patients previously stabilized after ≥ 3 years of enzyme therapy (imiglucerase or velaglucerase alfa). This post-hoc analysis examined safety and efficacy in the 30 ENCORE patients who were receiving velaglucerase alfa at study entry and were randomized to eliglustat (n = 22) or imiglucerase (n = 8). Efficacy and safety in velaglucerase alfa-transitioned patients were consistent with the full ENCORE trial population; 90% of patients switched to eliglustat and 88% of patients switched to imiglucerase met the composite endpoint (stable hemoglobin concentration, platelet count, spleen volume, and liver volume). Clinical stability was maintained for 12 months in Gaucher disease type 1 patients in the ENCORE trial who switched from velaglucerase alfa to either eliglustat or imiglucerase.

Detecting and accounting for violations of the constancy assumption in non-inferiority clinical trials

Randomized, placebo-controlled clinical trials are the gold standard for evaluating a novel therapeutic agent. In some instances, it may not be considered ethical or desirable to complete a placebo-controlled clinical trial and, instead, the placebo is replaced by an active comparator with the objective of showing either superiority or non-inferiority to the active comparator. In a non-inferiority trial, the experimental treatment is considered non-inferior if it retains a pre-specified proportion of the effect of the active comparator as represented by the non-inferiority margin. A key assumption required for valid inference in the non-inferiority setting is the constancy assumption, which requires that the effect of the active comparator in the non-inferiority trial is consistent with the effect that was observed in previous trials. It has been shown that violations of the constancy assumption can result in a dramatic increase in the rate of incorrectly concluding non-inferiority in the presence of ineffective or even harmful treatment. In this paper, we illustrate how Bayesian hierarchical modeling can be used to facilitate multi-source smoothing of the data from the current trial with the data from historical studies, enabling direct probabilistic evaluation of the constancy assumption. We then show how this result can be used to adapt the non-inferiority margin when the constancy assumption is violated and present simulation results illustrating that our method controls the type-I error rate when the constancy assumption is violated, while retaining the power of the standard approach when the constancy assumption holds. We illustrate our adaptive procedure using a non-inferiority trial of raltegravir, an antiretroviral drug for the treatment of HIV.

Room temperature stable carbetocin for the prevention of postpartum haemorrhage during the third stage of labour in women delivering vaginally: study protocol for a randomized controlled trial

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality in low-income countries and contributes to nearly a quarter of maternal deaths globally. The current available interventions for prevention of postpartum haemorrhage, oxytocin and carbetocin, are limited by their need for refrigeration to maintain potency, as the ability to maintain a cold chain across the drug distribution and storage network is inconsistent, thus restricting their use in countries with the highest burden of maternal mortality. We describe a randomized, double-blind non-inferiority trial comparing a newly developed room temperature stable formulation of carbetocin to the standard intervention (oxytocin) for the prevention of PPH after vaginal birth.

METHODS/DESIGN

Approximately 30,000 women delivering vaginally will be recruited across 22 centres in 10 countries. The primary objectives are to evaluate the non-inferiority of room temperature stable carbetocin (100 μg intramuscular) versus oxytocin (10 IU intramuscular) in the prevention of PPH and severe PPH after vaginal birth. The primary endpoints are blood loss ≥500 mL or the use of additional uterotonics (composite endpoint required by drug regulatory authorities) and blood loss ≥1,000 mL (WHO requirement). Non-inferiority will be assessed using a two-sided 95 % confidence interval for the relative risk of the above endpoints for room temperature stable carbetocin versus oxytocin. The upper limit of the two-sided 95 % confidence interval for the relative risk for the composite endpoint of blood loss ≥500 mL or the use of additional uterotonics, and for the endpoint of blood loss ≥1,000 mL, will be compared to a non-inferiority margin of 1.16 and 1.23, respectively. If the upper limit is below the corresponding margin, non-inferiority will have been demonstrated. The safety analysis will include all women receiving treatment. Safety and tolerability will be assessed by a review of adverse events, by conducting inferential testing with significance levels for between-group comparisons.

DISCUSSION

If the results of the study show that room temperature stable carbetocin is a safe and effective alternative to oxytocin, this could have a substantial impact on the prevention of postpartum haemorrhage and maternal survival worldwide.

TRIAL REGISTRATION

ACTRN12614000870651 (14 August 2014).

Comparative effectiveness of cognitive and dynamic therapies for major depressive disorder in a community mental health setting: study protocol for a randomized non-inferiority trial

BACKGROUND

There is substantial evidence that cognitive therapy is an effective intervention for the treatment of major depressive disorder. Although dynamic psychotherapies have been widely studied and are commonly practiced worldwide, there are few randomized comparisons of cognitive therapy and dynamic therapy for major depressive disorder.

METHODS

We are completing data collection on a randomized non-inferiority trial comparing the effectiveness of cognitive therapy and short-term dynamic psychotherapy in the treatment of major depressive disorder in the community mental health setting. Therapists employed in the community setting have been recruited for training in either short-term dynamic psychotherapy or cognitive therapy. Patients seeking services at the community site who meet criteria for major depressive disorder based on a blind independent diagnostic interview are randomized to 16 sessions of treatment. All patients are assessed at baseline and months 1, 2, 4, and 5 utilizing a comprehensive battery.

DISCUSSION

This study adds to the growing literature evaluating the effectiveness of short-term dynamic psychotherapy for specific diagnostic groups. These results will have implications for the dissemination of effective interventions for major depressive disorder in community mental health settings.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov, a service of the United States National Institute of Health. NIH Identifier: NCT01207271. Registered 21 September 2010.

Pentoxifylline vs. corticosteroid to treat severe alcoholic hepatitis: a randomised, non-inferiority, open trial

BACKGROUND & AIMS

Both corticosteroid and pentoxifylline reduce short-term mortality in severe alcoholic hepatitis. However, few studies have directly compared the efficacy of pentoxifylline and corticosteroid in patients with this condition.

METHODS

In this multicentre, open-labelled, randomised non-inferiority trial, we assigned 121 patients with severe alcoholic hepatitis (Maddrey's discriminant function ⩾32) to receive either pentoxifylline (400 mg, 3 times daily, in 62 subjects) or prednisolone (40 mg daily, in 59 subjects). The primary end point was non-inferiority in survival at the 1 month time point for the pentoxifylline treatment compared with prednisolone.

RESULTS

The 1-month survival rate of patients receiving pentoxifylline was 75.8% (15 deaths) compared with 88.1% (7 deaths) in those, taking prednisolone, for a treatment difference of 12.3% (95% confidence interval, -4.2% to 28.7%; p = 0.08). The 95% confidence interval for the observed difference exceeded the predefined margin of non-inferiority (Δ15%) and included zero. The 6-month survival rate was not significantly different between the pentoxifylline and prednisolone groups (64.5% vs. 72.9%; p = 0.23). At 7 days, the response to therapy assessed by the Lille model was significantly lower in the prednisolone group (n = 58) than in the pentoxifylline group (n = 5 9): 0.35 vs. 0.50 (p = 0.012). Hepatitis complications, including hepatorenal syndrome and side effects, such as infection and gastrointestinal bleeding, were similar in the two groups.

CONCLUSIONS

The findings demonstrate that the efficacy of the pentoxifylline is not statistically equivalent to the efficacy of prednisolone, supporting the use of prednisolone as a preferred treatment option in patients with severe alcoholic hepatitis.

Centchroman regresses mastalgia: a randomized comparison with danazol

We conducted a randomized trial to evaluate effectiveness of Centchroman in control of mastalgia and compared it with Danazol. Research Question- Is proportion of pain relief achieved by Centchroman similar to or inferior to that achieved by Danazol? In a randomized controlled trial of Centchroman vs. Danazol in mastalgia, 81 patients with mastalgia were studied. Thirty-nine patients were randomized to Danazol arm and 42 in Centchroman arm. The treatment was given for 12 weeks, followed by observation for 12 weeks. The pain was measured by visual analogue scale (VAS) of 0-10. At 12 weeks 89.7% women achieved reduction in pain score to ≤3 in Centchroman group (pvalue 0.001). In Danazol group 69.44% women achieved reduction in pain score to ≤ 3 (p = 0.001). Three months after stopping therapy, Centchroman was more effective in pain score reduction at 24 weeks as compared to Danazol (p = 0.019). Centchroman is an effective, safe and inexpensive alternative to Danazol for treatment of mastalgia.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s12262-010-0216-z) contains supplementary material, which is available to authorized users.