Watchman outcomes comparing post-implantation anticoagulation with warfarin versus direct oral anticoagulants

PURPOSE

As left atrial appendage occlusion devices (LAAO) implantation rates grow, continued evaluation on best patient practices is important. We report pooled Watchman outcomes at a multicenter Texas healthcare system with an emphasis on clinical outcomes and post-implantation anticoagulation with direct oral anticoagulants (DOACs) versus warfarin.

METHODS

Data for 163 patients with atrial fibrillation (AF) undergoing Watchman implantation was collected via retrospective chart review between June 2016 and June 2018. A Fisher's exact test was utilized to evaluate associations in bivariate comparisons of categorical data. Tests of non-inferiority, applied between DOACs and warfarin, utilized a ratio of 2.

RESULTS

Outcomes were significant for similar rates of stroke, disabling stroke, major bleeds, and all-cause mortality when compared to published clinical trials. Most patients with cerebrovascular events were found to have >5 mm peri-device leaks (PDLs), were on warfarin at the time of the event (75%), and all occurred within the first 6 months post implant. A significant number of patients were discharged on DOACs (42%). DOACs were shown to be non-inferior to warfarin with respect to stroke (p = 0.0048), disabling stroke (p = 0.0383), gastrointestinal bleeding (p = 0.0287), mortality (p = 0.0165), and combined adverse outcomes (p = 0.0040). DOACs were associated with less combined adverse outcomes (p = 0.021).

CONCLUSION

Our findings suggest that additional imaging or aggressive management of PDLs in Watchman recipients within the initial 6-month follow-up may aid in reducing stroke rates. Additionally, anticoagulation with DOACs' post Watchman implantation was found non-inferior to warfarin, with some evidence of lower risk for adverse outcomes favoring DOACs.

Fixed-dose combination of indacaterol/glycopyrronium/mometasone furoate once-daily versus salmeterol/fluticasone twice-daily plus tiotropium once-daily in patients with uncontrolled asthma: A randomised, Phase IIIb, non-inferiority study (ARGON)

BACKGROUND

The efficacy and safety of once-daily (o.d.) fixed-dose combination of indacaterol (IND), glycopyrronium (GLY) and mometasone furoate (MF) via Breezhaler® versus concurrent administration of salmeterol/fluticasone (SAL/FLU) twice-daily (b.i.d.) via Accuhaler®+Tiotropium (TIO) o.d. via Respimat® was evaluated in patients with uncontrolled asthma.

METHODS

Patients (aged ≥18 years), symptomatic (Asthma Control Questionnaire [ACQ]-7 ≥1.5) despite treatment with long-acting β₂-agonist/inhaled corticosteroid medium- or high-dose, received IND/GLY/MF high- (150/50/160 μg) or medium-dose (150/50/80 μg) o.d. or SAL/FLU high-dose (50/500 μg) b.i.d.+Tio 5 μg o.d. for 24 weeks. The primary objective was to confirm the non-inferiority of either dose of IND/GLY/MF to SAL/FLU high dose + TIO in terms of Asthma Quality of Life Questionnaire (AQLQ). Additional endpoints: ACQ-7, lung function, health status (St George's Respiratory Questionnaire [SGRQ]), exacerbations, and safety after 24 weeks.

RESULTS

IND/GLY/MF high- and medium-dose met the primary endpoint, confirming non-inferiority to SAL/FLU high dose + TIO for AQLQ (least square mean treatment difference [Δ]: 0.073 and -0.038, respectively; both p < 0.001). IND/GLY/MF high-dose improved ACQ-7 (Δ: -0.124; p = 0.004), trough FEV₁ (Δ: 96 mL; p < 0.001), peak expiratory flow (morning [Δ: 9.56 L/min; p = 0.005], evening [Δ: 9.15 L/min; p = 0.006]) and SGRQ (Δ: -2.00; p = 0.04) versus SAL/FLU high dose + TIO. Improvements in these endpoints were comparable for IND/GLY/MF medium-dose and SAL/FLU high dose + TIO. Adverse events were generally comparable across treatments.

CONCLUSIONS

IND/GLY/MF high- and medium-dose o.d. via a single inhaler were non-inferior to SAL/FLU high-dose b.i.d. + TIO o.d. via two inhalers for AQLQ. IND/GLY/MF high-dose o.d. improved lung function, asthma control and health status versus SAL/FLU high dose + TIO, while IND/GLY/MF medium-dose had comparable efficacy but at a corresponding lower steroid dose.

Early switch from intravenous to oral antibiotic therapy in patients with cancer who have low-risk neutropenic sepsis (the EASI-SWITCH trial): study protocol for a randomised controlled trial

BACKGROUND

Neutropenic sepsis remains a common treatment complication for patients receiving systemic anti-cancer treatment. The UK National Institute for Health and Care Excellence have not recommended switching from empirical intravenous antibiotics to oral antibiotics within 48 h for patients assessed as low risk for septic complications because of uncertainty about whether this would achieve comparable outcomes to using intravenous antibiotics for longer. The UK National Institute for Health Research funded the EASI-SWITCH trial to tackle this uncertainty.

METHODS

The trial is a pragmatic, randomised, non-inferiority trial that aims to establish the clinical and cost-effectiveness of early switching from intravenous to oral antibiotics in cancer patients with low-risk neutropenic sepsis. Patients ≥ 16 years, receiving systemic anti-cancer treatment (acute leukaemics/stem cell transplants excluded), with a temperature of > 38 °C, neutrophil count ≤ 1.0 × 109/L, MASCC (Multinational Association of Supportive Care in Cancer) score ≥ 21 and receiving IV piperacillin/tazobactam or meropenem for less than 24 h are eligible to participate. Patients are randomised 1:1 either (i) to switch to oral ciprofloxacin and co-amoxiclav within 12-24 h of commencing intravenous antibiotics, completing at least 5 days total antibiotics (intervention), or (ii) to continue intravenous antibiotics for at least 48 h, with ongoing antibiotics being continued at the physician's discretion (control). Patients are discharged home when their physician deems it appropriate. The primary outcome measure is a composite of treatment failures as assessed at day 14. The criteria for treatment failure include fever persistence or recurrence 72 h after starting intravenous antibiotics, escalation from protocolised antibiotics, hospital readmission related to infection/antibiotics, critical care support or death. Based on a 15% treatment failure rate in the control group and a 15% non-inferiority margin, the recruitment target is 230 patients.

DISCUSSION

If the trial demonstrates non-inferiority of early switching to oral antibiotics, with potential benefits for patient quality of life and resource savings, this finding will have significant implications for the routine clinical management of those with low-risk neutropenic sepsis.

TRIAL REGISTRATION

ISRCTN: 84288963. Registered on the 1 July 2015. https://doi.org/10.1186/ISRCTN84288963. EudraCT: 2015-002830-35.

Trastuzumab, pertuzumab, and eribulin mesylate versus trastuzumab, pertuzumab, and a taxane as a first-line or second-line treatment for HER2-positive, locally advanced or metastatic breast cancer: study protocol for a randomized controlled, non-inferiority, phase III trial in Japan (JBCRG-M06/EMERALD)

Background

Trastuzumab (Tmab), pertuzumab (Pmab), and taxane has been a standard first-line treatment for recurrent or metastatic human epidermal growth factor (HER2)-positive breast cancer (HER2⁺ mBC) but has some safety issues due to taxane-induced toxicities. This has led to ongoing efforts to seek less toxic alternatives to taxanes that are equally effective when used in combination with Tmab plus Pmab. This study aims to show the non-inferiority of eribulin, a non-taxane microtubule inhibitor, against taxane, as a partner for dual HER2 blockade.

Methods/design

This multicenter, randomized, open-label, parallel-group, phase III study will involve a total of 480 Japanese women with HER2⁺ mBC who meet the following requirements: (1) age 20–70 years; (2) no prior cytotoxic chemotherapy (excluding trastuzumab-emtansine) for mBC; (3) ≥ 6 months after prior neoadjuvant or adjuvant cytotoxic chemotherapy; (4) presence of any radiologically evaluable lesion; (5) left ventricular ejection fraction ≥ 50%; (6) Eastern Cooperative Oncology Group performance status score of 0 or 1; (7) adequate organ function; and (8) life expectancy of at least 6 months. They will be randomized 1:1 to receive eribulin (1.4 mg/m² on days 1 and 8) or taxane (docetaxel 75 mg/m² on day 1 or paclitaxel 80 mg/m² on days 1, 8, and 15) in combination with Tmab (8 mg/kg then 6 mg/kg) plus Pmab (840 mg then 420 mg) on day 1 of each 21-day cycle. The treatment will be continued until disease progression or unmanageable toxicity. The primary endpoint is progression-free survival as per investigator according to RECIST v1.1 criteria. Key secondary endpoints include objective response rate, overall survival, quality of life and safety. Non-inferiority will be tested with two margins of 1.33 and 1.25 in a stepwise manner. If non-inferiority is shown with a margin of 1.25, superiority will then be tested.

Discussion

If this study shows the non-inferiority, or even superiority, of Tmab, Pmab, and eribulin against the existing taxane-containing regimen, this new regimen may become a standard first- or second-line treatment option for HER2⁺ mBC in Japan.

Trial registration

ClinicalTrials.gov, ID: NCT03264547. Registered on 28 June 2017.

An optimised dosing regimen versus a standard dosing regimen of vancomycin for the treatment of late onset sepsis due to Gram-positive microorganisms in neonates and infants aged less than 90 days (NeoVanc): study protocol for a randomised controlled trial

BACKGROUND

Vancomycin has been used in clinical practice for over 50 years; however, validated, pharmacokinetic (PK) data relating clinical outcomes to different dosing regimens in neonates are lacking. Coagulase negative staphylococci (CoNS) are the most commonly isolated organisms in neonatal, late-onset sepsis (LOS). Optimised use to maximise efficacy while minimising toxicity and resistance selection is imperative to ensure vancomycin's continued efficacy.

METHODS

NeoVanc is a European, open-label, Phase IIb, randomised, controlled, non-inferiority trial comparing an optimised vancomycin regimen to a standard vancomycin regimen when treating LOS known/suspected to be caused by Gram-positive organisms (excluding Staphylococcus aureus) in infants aged ≤ 90 days. Three hundred infants will be recruited and randomised in a 1:1 ratio. Infants can be recruited if they have culture confirmed (a positive culture from a normally sterile site and at least one clinical/laboratory criterion) or clinical sepsis (presence of any ≥ 3 clinical/laboratory criteria) in the 24 h before randomisation. The optimised regimen consists of a vancomycin loading dose (25 mg/kg) followed by 5 ± 1 days of 15 mg/kg q12h or q8h, dependent on postmenstrual age (PMA). The standard regimen is a 10 ± 2 day vancomycin course at 15 mg/kg q24h, q12h or q8h, dependent on PMA. The primary endpoint is a successful outcome at the test of cure visit (10 ± 1 days after the end of vancomycin therapy). A successful outcome consists of the patient being alive, having successfully completed study vancomycin therapy and having not had a clinical/microbiological relapse/new infection requiring treatment with vancomycin or other anti-staphylococcal antibiotic for > 24 h. Secondary endpoints include clinical/microbiological relapse/new infection at the short-term follow-up visit (30 ± 5 days after the initiation of vancomycin), evaluation of safety (renal/hearing), vancomycin PK and assessment of a host biomarker panel over the course of vancomycin therapy.

DISCUSSION

Based on previous pre-clinical data and a large meta-analysis of neonatal, PK/pharmacodynamic data, NeoVanc was set up to provide evidence on whether a loading dose followed by a short vancomycin course is non-inferior, regarding efficacy, when compared to a standard, longer course. If non-inferiority is demonstrated, this would support adoption of the optimised regimen as a way of safely reducing vancomycin exposure when treating neonatal, Gram-positive LOS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02790996. Registered on 7 April 2016. EudraCT, 2015-000203-89. Entered on 18 July 2016.

Is moving from targeted culling to BCG-vaccination of badgers (Meles meles) associated with an unacceptable increased incidence of cattle herd tuberculosis in the Republic of Ireland? A practical non-inferiority wildlife intervention study in the Republic of Ireland (2011-2017)

Bovine tuberculosis (BTB) remains as a costly disease of cattle-herds in the Republic of Ireland (ROI). This persistence is partially attributable to the presence of M. bovis infection in a wildlife reservoir, the European badger (Meles meles). Thus, both area-wide and limited-area targeted-badger-culling have been part of the ROI-BTB control/eradication program to help reduce the future incidence of a cattle-herd BTB breakdown (i.e. a "new herd-level occurrence of BTB"). However, neither badger-culling practice can be sustained as a major component in the ongoing BTB eradication program in the ROI. Vaccination of badgers with Bacille Calmette-Guérin (BCG) has been proposed as an alternative to badger culling. Thus, in 2011, a five-year non-inferiority study was implemented in seven counties in the ROI. This study was designed to compare and contrast the cattle-herd-BTB-incidence in areas where intramuscular badger vaccination would be implemented versus the cattle-herd-BTB-incidence in the remaining area of the same county where targeted-badger-culling was maintained as the standard treatment response to probable badger-sourced BTB breakdowns. Our outcome of interest was a new cattle-herd-BTB-episode (breakdown) with a total of >2 standard skin-test (SICTT) reactors detected during the episode. Treatments (badger vaccination or targeted badger culling) were cluster allocated based on where the majority of the herd owner's land was located. To assess the impact of the two treatments, we compared the incidence-risk, of our defined outcome, for cattle herds in the area under vaccination to the outcome incidence-risk for cattle herds in the remainder of the same county after 4 and 5 years of having implemented badger vaccination. A random-effects logit model with adjustment for clustering by treatment, and statistical control of herd-type, herd-size and five-year prior-BTB-episode history was used for our analyses. Although not included in the logistic model, a relative badger density metric based on the annual number of badgers captured-per-sett-night of capturing effort was developed for each treatment area; this metric indicated that relative badger density was approximately 40 % higher in vaccination areas than in the targeted badger-culling areas during our study. Overall, our study results indicated that vaccination was not inferior to targeted badger-culling in four counties and badger vaccination was deemed to produce ambivalent results in one (County Cork North) of the seven study sites in the ROI. A post-study investigation, in County Galway, where vaccination was deemed inferior to target culling, revealed that widespread purchases of cattle from a nearby cattle mart, by herd owners in the vaccination-area, was associated with the increased herd and vaccination-area risk of BTB. No single "biasing hypothesis" was evident for the apparent vaccine inferiority in the second study site (County Monaghan) where vaccination was deemed inferior to targeted culling; hence no further investigations were conducted.

Effectiveness of intramuscular gluteal glucocorticoid injection versus intra-articular glucocorticoid injection in knee osteoarthritis: design of a multicenter randomized, 24 weeks comparative parallel-group trial

Background

The knee is symptomatically the most frequent affected joint in osteoarthritis and, in the Netherlands and other Western countries, is mainly managed by general practitioners (GPs). An intra-articular glucocorticoid injection is recommended in (inter) national guidelines for patients with knee osteoarthritis as an option for a flare of knee pain and/or for those who are not responding well to pain medication. An innovative approach that could replace the intra-articular injection is an intramuscular gluteal glucocorticoid injection. An intramuscular injection is easier to perform than an intra-articular injection with lesser risk of severe local adverse reactions. We hypothesize that intramuscular gluteal glucocorticoid injection is non-inferior in reducing knee pain compared to intra-articular glucocorticoid injection, with potentially a longer lasting effect than intra-articular injection.

Methods/design

The study will be a pragmatic randomized controlled non-inferiority trial with two parallel groups. A total of 140 patients aged 45 years and older with knee osteoarthritis who contacted their general practitioner and have persistent knee pain (score ≥ 3 on 0–10 numerical rating scale; 0 = no knee pain) will be included.

Patients will be randomly allocated (1:1) to an injection of 40 mg triamcinolone acetonide intra-articular in the knee joint or intramuscular in the ipsilateral ventrogluteal area.

The effect of treatment will be evaluated by questionnaires at 2, 4, 8, 12, and 24 weeks after injection. The primary outcome is patients’ reported severity of knee pain measured with the pain subscale of the Knee injury and Osteoarthritis Outcome Score 4 weeks after injection. Statistical analysis will be based on both the per-protocol and the intention-to-treat principle.

Discussion

This study will evaluate non-inferiority of intramuscular glucocorticoid injection compared to intra-articular glucocorticoid injection for knee osteoarthritis symptoms.

Trial registration

This trial is registered in the Dutch Trial Registry (number NTR6968) at 2018-01-22 (https://www.trialregister.nl/trial/6784). Issue date: 1 October 2019.

Trial sponsor

Erasmus MC University Medical Center Rotterdam.

PO-box 2040.

3000 CA Rotterdam.

The Netherlands.

Immunogenicity and safety of the RTS,S/AS01 malaria vaccine co-administered with measles, rubella and yellow fever vaccines in Ghanaian children: A phase IIIb, multi-center, non-inferiority, randomized, open, controlled trial

BACKGROUND

To optimize vaccine implementation visits for young children, it could be efficient to administer the first RTS,S/AS01 malaria vaccine dose during the Expanded Programme on Immunization (EPI) visit at 6 months of age together with Vitamin A supplementation and the third RTS,S/AS01 dose on the same day as yellow fever (YF), measles and rubella vaccines at 9 months of age. We evaluated the safety and immunogenicity of RTS,S/AS01 when co-administered with YF and combined measles-rubella (MR) vaccines.

METHODS

In this phase 3b, open-label, controlled study (NCT02699099), 709 Ghanaian children were randomized (1:1:1) to receive RTS,S/AS01 at 6, 7.5 and 9 months of age, and YF and MR vaccines at 9 or 10.5 months of age (RTS,S coad and RTS,S alone groups, respectively). The third group received YF and MR vaccines at 9 months of age and will receive RTS,S/AS01 at 10.5, 11.5 and 12.5 months of age (Control group). All children received Vitamin A at 6 months of age. Non-inferiority of immune responses to the vaccine antigens was evaluated 1 month following co-administration versus RTS,S/AS01 or EPI vaccines (YF and MR vaccines) alone using pre-defined non-inferiority criteria. Safety was assessed until Study month 4.5.

RESULTS

Non-inferiority of antibody responses to the anti-circumsporozoite and anti-hepatitis B virus surface antigens when RTS,S/AS01 was co-administered with YF and MR vaccines versus RTS,S/AS01 alone was demonstrated. Non-inferiority of antibody responses to the measles, rubella, and YF antigens when RTS,S/AS01 was co-administered with YF and MR vaccines versus YF and MR vaccines alone was demonstrated. The safety profile of all vaccines was clinically acceptable in all groups.

CONCLUSIONS

RTS,S/AS01 can be co-administered with Vitamin A at 6 months and with YF and MR vaccines at 9 months of age during EPI visits, without immune response impairment to any vaccine antigen or negative safety effect.

High-dose rifapentine with or without moxifloxacin for shortening treatment of pulmonary tuberculosis: Study protocol for TBTC study 31/ACTG A5349 phase 3 clinical trial

INTRODUCTION

Phase 2 clinical trials of tuberculosis treatment have shown that once-daily regimens in which rifampin is replaced by high dose rifapentine have potent antimicrobial activity that may be sufficient to shorten overall treatment duration. Herein we describe the design of an ongoing phase 3 clinical trial testing the hypothesis that once-daily regimens containing high dose rifapentine in combination with other anti-tuberculosis drugs administered for four months can achieve cure rates not worse than the conventional six-month treatment regimen.

METHODS/DESIGN

S31/A5349 is a multicenter randomized controlled phase 3 non-inferiority trial that compares two four-month regimens with the standard six-month regimen for treating drug-susceptible pulmonary tuberculosis in HIV-negative and HIV-positive patients. Both of the four-month regimens contain high-dose rifapentine instead of rifampin, with ethambutol replaced by moxifloxacin in one regimen. All drugs are administered seven days per week, and under direct observation at least five days per week. The primary outcome is tuberculosis disease-free survival at twelve months after study treatment assignment. A total of 2500 participants will be randomized; this gives 90% power to show non-inferiority with a 6.6% margin of non-inferiority.

DISCUSSION

This phase 3 trial formally tests the hypothesis that augmentation of rifamycin exposures can shorten tuberculosis treatment to four months. Trial design and standardized implementation optimize the likelihood of obtaining valid results. Results of this trial may have important implications for clinical management of tuberculosis at both individual and programmatic levels.

TRIAL REGISTRATION

NCT02410772. Registered 8 April 2015,https://www.clinicaltrials.gov/ct2/show/NCT02410772?term=02410772&rank=1.

Efficacy and safety of adjunctive therapy using esketamine or racemic ketamine for adult treatment-resistant depression: A randomized, double-blind, non-inferiority study

BACKGROUND

Ketamine and its enantiomers have recently been highlighted as one of the most effective therapeutic options in refractory depression. However, racemic ketamine and esketamine have not been directly compared. The aim of this study is to assess the efficacy and safety of esketamine compared to ketamine in patients with treatment-resistant depression (TRD).

METHODS

This is a randomized, double-blind, active-controlled, bicentre, non-inferiority clinical trial, with two parallel groups. Participants were randomly assigned to a 40-min single intravenous infusion of ketamine 0.5 mg/kg or esketamine 0.25 mg/kg. The primary outcome was the difference in remission rates for depression 24 h following intervention using the Montgomery-Åsberg Depression Rating Scale (MADRS), with a non-inferiority margin of 20%.

RESULTS

63 subjects were included and randomly assigned (29 to receive ketamine and 34 to receive esketamine). At 24 h, 24.1% of participants in the ketamine group and 29.4% of participants in the esketamine group showed remission, with a difference of 5.3% (95% CILB -13.6%), confirming non-inferiority. MADRS scores improved from 33 (SD 9.3) to 16.2 (SD 10.7) in the ketamine group and from 33 (SD 5.3) to 17.5 (SD 12.2) in the esketamine one, with a difference of -5.27% (95% CILB, -13.6). Both groups presented similar mild side effects.

CONCLUSIONS

Esketamine was non-inferior to ketamine for TRD 24 h following infusion. Both treatments were effective, safe, and well tolerated.

TRIAL REGISTRATION

Registered in Japan Primary Registries Network: UMIN000032355.

Self-cut titanium-coated polypropylene mesh versus pre-cut mesh-kit for transvaginal treatment of severe pelvic organ prolapse: study protocol for a multicenter non-inferiority trial

BACKGROUND

Pelvic organ prolapse (POP) is a common health problem and has significant negative effects on a woman's quality of life. The transvaginal mesh procedure is a durable reconstructive surgery, but the mesh kits are expensive for underdeveloped countries. Our previous case-series study showed that the use of self-cut mesh had a good success rate (91.8% at 1-year follow-up) and low complication rate. This trial is designed to compare a self-cut titanium-coated polypropylene mesh procedure with a mesh kit for the treatment of symptomatic stage III-IV anterior or apical prolapse in terms of efficacy, safety and cost-effectiveness.

METHODS

The trial is a randomized controlled multicenter non-inferiority trial. The primary outcome measure is the composite success rate at 1-year follow-up. The secondary outcomes are anatomic outcomes of each vaginal segment (anterior, posterior and apical) using the POP-Q score, subjective improvement of quality of life according to questionnaires, intraoperative parameters, complications and costs. Analysis will be performed according to the intention-to-treat principle. Based on a comparable success rate of 90% and 10% as the margin (β = 0.2 and one-sided α = 0.025), about 312 patients in total from 11 centers will be recruited including 10% dropout. The aims of the research are to demonstrate whether the self-cut mesh procedure is non-inferior to the mesh-kit procedure and to investigate the performance of titanium-coated mesh for vaginal prolapse repair.

DISCUSSION

This multicenter non-inferiority trial will evaluate whether the efficacy and safety of self-cut mesh is non-inferior to mesh kits in women with severe symptomatic stage III-IV anterior or apical prolapse. If we are able to show that the self-cut mesh procedure is non-inferior to the mesh-kit procedure in success rates, then the self-cut mesh procedure may be more cost-effective.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03283124. Registered on 17 January 2018.

Handling an uncertain control group event risk in non-inferiority trials: non-inferiority frontiers and the power-stabilising transformation

Background

Non-inferiority trials are increasingly used to evaluate new treatments that are expected to have secondary advantages over standard of care, but similar efficacy on the primary outcome. When designing a non-inferiority trial with a binary primary outcome, the choice of effect measure for the non-inferiority margin (e.g. risk ratio or risk difference) has an important effect on sample size calculations; furthermore, if the control event risk observed is markedly different from that assumed, the trial can quickly lose power or the results become difficult to interpret.

Methods

We propose a new way of designing non-inferiority trials to overcome the issues raised by unexpected control event risks. Our proposal involves using clinical judgement to specify a ‘non-inferiority frontier’, i.e. a curve defining the most appropriate non-inferiority margin for each possible value of control event risk. Existing trials implicitly use frontiers defined by a fixed risk ratio or a fixed risk difference. We discuss their limitations and propose a fixed arcsine difference frontier, using the power-stabilising transformation for binary outcomes, which may better represent clinical judgement. We propose and compare three ways of designing a trial using this frontier: testing and reporting on the arcsine scale; testing on the arcsine scale but reporting on the risk difference or risk ratio scale; and modifying the margin on the risk difference or risk ratio scale after observing the control event risk according to the power-stabilising frontier.

Results

Testing and reporting on the arcsine scale leads to results which are challenging to interpret clinically. For small values of control event risk, testing on the arcsine scale and reporting results on the risk difference scale produces confidence intervals at a higher level than the nominal one or non-inferiority margins that are slightly smaller than those back-calculated from the power-stabilising frontier alone. However, working on the arcsine scale generally requires a larger sample size compared to the risk difference scale. Therefore, working on the risk difference scale, modifying the margin after observing the control event risk, might be preferable, as it requires a smaller sample size. However, this approach tends to slightly inflate type I error rate; a solution is to use a slightly lower significance level for testing, although this modestly reduces power. When working on the risk ratio scale instead, the same approach based on the modification of the margin leads to power levels above the nominal one, maintaining type I error under control.

Conclusions

Our proposed methods of designing non-inferiority trials using power-stabilising non-inferiority frontiers make trial design more resilient to unexpected values of the control event risk, at the only cost of requiring somewhat larger sample sizes when the goal is to report results on the risk difference scale.

Telehealth Delivery of Memory Rehabilitation Following Stroke

OBJECTIVE

Rehabilitation of memory after stroke remains an unmet need. Telehealth delivery may overcome barriers to accessing rehabilitation services.

METHOD

We conducted a non-randomized intervention trial to investigate feasibility and effectiveness of individual telehealth (internet videoconferencing) and face-to-face delivery methods for a six-week compensatory memory rehabilitation program. Supplementary analyses investigated non-inferiority to an existing group-based intervention, and the role of booster sessions in maintaining functional gains. The primary outcome measure was functional attainment of participants' goals. Secondary measures included subjective reports of lapses in everyday memory and prospective memory, reported use of internal and external memory strategies, and objective measures of memory functioning.

RESULTS

Forty-six stroke survivors were allocated to telehealth and face-to-face intervention delivery conditions. Feasibility of delivery methods was supported, and participants in both conditions demonstrated treatment-related improvements in goal attainment, and key subjective outcomes of everyday memory, and prospective memory. Gains on these measures were maintained at six-week follow-up. Short-term gains in use of internal strategies were also seen. Non-inferiority to group-based delivery was established only on the primary measure for the telehealth delivery condition. Booster sessions were associated with greater maintenance of gains on subjective measures of everyday memory and prospective memory.

CONCLUSIONS

This exploratory study supports the feasibility and potential effectiveness of telehealth options for remote delivery of compensatory memory skills training after a stroke. These results are also encouraging of a role for booster sessions in prolonging functional gains over time.

1g versus 2 g daily intravenous ceftriaxone in the treatment of community onset pneumonia - a propensity score analysis of data from a Japanese multicenter registry

BACKGROUND

Community-onset pneumonia (COP) is a combined concept of community acquired pneumonia and the previous classification of healthcare-associated pneumonia. Although ceftriaxone (CRO) is one of the treatment choices for COP, it is unclear whether 1 or 2 g CRO daily has better efficacy. We compared the effectiveness of 1 g with 2 g of CRO for COP treatment. We hypothesized that 1 g CRO would show non-inferiority over 2 g CRO.

METHODS

This study was an analysis of prospectively registered data of the patients with COP from four Japanese hospitals (the Adult Pneumonia Study Group-Japan: APSG-J). We included subjects who were initially treated solely with 1 or 2 g of CRO. The propensity score was estimated from the 33 pre-treatment variables, including age, sex, weight, pre-existing comorbidities, prescribed drugs, risk factors for aspiration pneumonia, vital signs, laboratory data, and a finding from chest xrays. The primary endpoint was the cure rate, for which a non-inferiority analysis was performed with a margin of 0.05. In addition, we performed three sensitivity analyses; using data limited to the group in which CRO solely was used until the completion of treatment, using data limited to inpatient cases, and performing a generalized linear mixed-effect logistic regression analysis to assess the primary outcome after adjusting for random hospital effects.

RESULTS

Of the 3817 adult subjects with pneumonia who were registered in the APSG-J study, 290 and 216 were initially treated solely with 1 or 2 g of CRO, respectively. Propensity score matching was used to extract 175 subjects in each group. The cure rate was 94.6 and 93.1% in the 1 and 2 g CRO groups, respectively (risk difference 1.5%; 95% confidence interval - 3.1 to 6.0; p = 0.009 for non-inferiority). The results of the sensitivity analyses were consistent with the primary result.

CONCLUSIONS

The propensity score-matched analysis of multicenter cohort data from Japan revealed that the cure rate for COP patients treated with 1 g daily CRO was non-inferior to that of patients treated with 2 g daily CRO.

A randomized noninferiority trial evaluating remotely-delivered stepped care for depression using internet cognitive behavioral therapy (CBT) and telephone CBT

This trial examined whether a stepped care program for depression, which initiated treatment with internet cognitive behavioral therapy, including telephone and messaging support, and stepped up non-responders to telephone-administered cognitive behavioral therapy (tCBT), was noninferior, less costly to deliver, and as acceptable to patients compared to tCBT alone. Adults with a diagnosis of major depressive episode (MDE) were randomized to receive up to 20 weeks of stepped care or tCBT. Stepped care (n = 134) was noninferior to tCBT (n = 136) with an end-of-treatment effect size of d = 0.03 and a 6-month post-treatment effect size of d = -0.07 [90% CI 0.29 to 0.14]. Therapist time in stepped care was 5.26 (SD = 3.08) hours versus 10.16 (SD 4.01) for tCBT (p < 0.0001), with a delivery cost difference of $-364.32 [95% CI $-423.68 to $-304.96]. There was no significant difference in pre-treatment preferences (p = 0.10) or treatment dropout (39 in stepped care; 27 in tCBT; p = 0.14). tCBT patients were significantly more satisfied than stepped care patients with the treatment they received (p < 0.0001). These findings indicate that stepped care was less costly to deliver, but no less effective than tCBT. There was no significant difference in treatment preference or completion, however satisfaction with treatment was higher in tCBT than stepped care. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01906476.

A Bayesian non-inferiority approach using experts' margin elicitation - application to the monitoring of safety events

BACKGROUND

When conducing Phase-III trial, regulatory agencies and investigators might want to get reliable information about rare but serious safety outcomes during the trial. Bayesian non-inferiority approaches have been developed, but commonly utilize historical placebo-controlled data to define the margin, depend on a single final analysis, and no recommendation is provided to define the prespecified decision threshold. In this study, we propose a non-inferiority Bayesian approach for sequential monitoring of rare dichotomous safety events incorporating experts' opinions on margins.

METHODS

A Bayesian decision criterion was constructed to monitor four safety events during a non-inferiority trial conducted on pregnant women at risk for premature delivery. Based on experts' elicitation, margins were built using mixtures of beta distributions that preserve experts' variability. Non-informative and informative prior distributions and several decision thresholds were evaluated through an extensive sensitivity analysis. The parameters were selected in order to maintain two rates of misclassifications under prespecified rates, that is, trials that wrongly concluded an unacceptable excess in the experimental arm, or otherwise.

RESULTS

The opinions of 44 experts were elicited about each event non-inferiority margins and its relative severity. In the illustrative trial, the maximal misclassification rates were adapted to events' severity. Using those maximal rates, several priors gave good results and one of them was retained for all events. Each event was associated with a specific decision threshold choice, allowing for the consideration of some differences in their prevalence, margins and severity. Our decision rule has been applied to a simulated dataset.

CONCLUSIONS

In settings where evidence is lacking and where some rare but serious safety events have to be monitored during non-inferiority trials, we propose a methodology that avoids an arbitrary margin choice and helps in the decision making at each interim analysis. This decision rule is parametrized to consider the rarity and the relative severity of the events and requires a strong collaboration between physicians and the trial statisticians for the benefit of all. This Bayesian approach could be applied as a complement to the frequentist analysis, so both Data Safety Monitoring Boards and investigators can benefit from such an approach.

Immunogenicity and safety of a liquid Pentavalent (DTwP-Hb-Hib) combination vaccine manufactured by Human Biologicals Institute in 6-8 weeks old healthy infants: A phase III, randomized, single blind, non-inferiority study

BACKGROUND

A liquid Pentavalent (DTwP-Hb-Hib) combination vaccine, developed by Human Biologicals Institute, underwent a Phase III clinical study in India. In this randomized, single blind, non-inferiority study, the immunogenicity and safety of this Investigational vaccine was compared with Pentavac SD® vaccine in 6-8 weeks old healthy infants.

METHODS

A total of 405 healthy infants aged 6-8 weeks old were randomized in 2:1 ratio to receive three doses of either the Investigational liquid Pentavalent (DTwP-Hb-Hib) combination vaccine or Pentavac SD® vaccine at four to six weeks interval. Immunogenicity was compared by estimation of antibody titers before the first dose and 4-6 weeks after the third dose of vaccination. Safety of each vaccine was assessed and compared by collection of data on solicited and unsolicited adverse events throughout the study period.

RESULTS

Out of a total of 405 enrolled subjects, 387 subjects completed the study. The seroconversion rates, seroprotection rates and geometric mean titres of the Investigational liquid Pentavalent (DTwP-Hb-Hib) combination vaccine group were found to be comparable and non-inferior to the Pentavac SD® vaccine group at 4-6 weeks after the third dose of vaccination. Pain, erythema and swelling at the site of injection were found to be the most common local adverse events whereas fever, irritability and unusual crying were found to be the most common systemic adverse events in both the vaccine groups. No vaccine related serious adverse event was reported. In this study, both the Investigational vaccine as well as the Comparator vaccine were found to be immunogenic and well tolerated.

CONCLUSION

After assessment of the results of the study it was concluded that the Investigational liquid Pentavalent (DTwP-Hb-Hib) combination vaccine developed by Human Biologicals Institute was immunogenic and safe when administered to infants aged 6-8 weeks and was non-inferior in immunogenicity and safety to Pentavac SD® vaccine. Clinical Trial Registry of India Identifier: CTRI/2016/01/006541.

A study protocol for an mHealth, multi-centre randomized control trial to promote use of postpartum contraception amongst rural women in Punjab, Pakistan

BACKGROUND

Provision of family planning services during the immediate post-partum phase is considered effective and cost-efficient for promoting healthy timing and spacing of pregnancies. This research aims to test the effectiveness of mobile phone-based interventions in promoting use of postpartum contraception. Moreover, it will also test the non-inferiority of text and voice messages compared to interactive phone-based counselling.

METHODS

A three-arm, 10-month, multicentre, randomized controlled trial will be conducted at 15 social franchise (SF) health facilities in Punjab province of Pakistan. Pregnant women aged 15-44 years who are in their first or second trimester and have a mobile phone for their own use will be eligible to participate in this study. The participants will be randomly allocated to one of three study arms: a) voice and text messages; b) interactive telephone-based counselling; or c) control arm (no additional phone-based support). The intervention counselling module will be developed based on the Integrated Behaviour Model which was recently adapted, and tested for the family planning context in Pakistan. It will broadly cover birth-preparedness, importance of birth spacing, and postnatal care. The phone-based intervention aims to improve women's ability to use contraception by providing them with information about a range of methods, access to family planning methods through outlets such as Suraj SF providers, connecting them with MSS field health educators to help them reach the centres, motivation by re-enforcing the benefits of contraceptive use on women's quality of life, and dispelling myths and misconceptions about modern contraceptive methods. Risk differences will be used as the measure of effect of the intervention on the outcomes.

DISCUSSION

The study findings will highlight effectiveness of mobile phone in raising awareness of maternal health and contraception, which in turn, is expected to be translated into increased proportion of: at least four antenatal visits, skilled birth or institutional delivery, postpartum contraceptive use, postnatal check-up, child immunization, and breastfeeding. Moreover, if the text and voice messages approach is proven to be non-inferior to interactive calls, it will provide evidence to making promotion of healthcare less resource intensive, and thereby contribute in improving the efficiency of the healthcare system.

TRIAL REGISTRATION

This trial was prospectively registered with the Clinical Trials registry ( NCT03612518 ) on August 2nd, 2018.

Self-directed or therapist-led parent training for children with attention deficit hyperactivity disorder? A randomized controlled non-inferiority pilot trial

BACKGROUND AND OBJECTIVES

Therapist-led behavioral parent training is a well-established treatment for behavior problems in children with attention-deficit/hyperactivity disorder (ADHD). However, parental attrition is high; self-directed forms of parent training may be a promising alternative. To date, no studies have compared these two forms of parent training in referred children with ADHD. The objectives of this pilot study were to examine the non-inferiority of a blended parent training (i.e. online program + supportive therapist contact) in comparison to its therapist-led equivalent (i.e. face-to-face parent training) regarding effects on behavioral problems, and to compare attrition rates, parental satisfaction, and therapist-time between both treatments.

METHODS

21 school-aged children with ADHD and behavioral problems, who had been referred to an outpatient mental health clinic, were randomized to blended (n = 11) or face-to-face (n = 10) parent training. Behavior problems were measured with the Child Behavior Checklist. Treatment completers and dropouts were included in the analyses.

RESULTS AND CONCLUSIONS

Blended parent training was not found to be non-inferior to face-to-face parent training in the reduction of behavior problems. Parents in the blended condition dropped out of treatment significantly earlier than parents in the face-to-face condition and were less satisfied. Therapists in the blended condition spent significantly less time on parent training than therapists in the face-to-face condition.

Comparison of SCAphoid fracture osteosynthesis by MAGnesium-based headless Herbert screws with titanium Herbert screws: protocol for the randomized controlled SCAMAG clinical trial

Background

Scaphoid fractures are the most common carpal fractures. They often need to be treated by surgery, where the use of a compression screw is the globally accepted gold standard. Surgeons may choose between different implant materials including titanium alloys, which remain in the body or are removed after healing. An alternative are biodegradable magnesium-based implants. Properties of magnesium alloys include high stability, osteoconductivity, potential reduction of infections and few artifacts in magnetic resonance imaging (MRI). The aim of this trial is to demonstrate non-inferiority of magnesium-based compression screws compared with titanium Herbert screws for scaphoid fractures.

Methods

The trial is designed as a multicenter, blinded observer, randomized controlled parallel two-group post market trial. Approximately 190 patients will be randomized (1:1) with stratification by center either to titanium or magnesium-based compression screws. Follow-up is 1 year per patient. Surgical procedures and aftercare will be performed according to the German treatment guideline for scaphoid fractures. The first primary endpoint is the patient-rated wrist evaluation (PRWE) score after 6 months. The second primary endpoint is a composite safety endpoint including bone union until 6 months, no adverse device effect (ADE) during surgery or wound healing and no serious ADE or reoperation within 1 year. The third primary endpoint is the difference in change MRI artifacts over time. Non-inferiority will be investigated for primary endpoints 1 (t-test confidence interval) and 2 (Wilson’s score interval) using both the full analysis set (FAS) and the per protocol population at the one-sided 2.5% test-level. Superiority of magnesium over titanium screws will be established using the FAS at the two-sided 5% test-level (Welch test) only if non-inferiority has been established for both primary endpoints. Secondary endpoints include quality of life.

Discussion

This study will inform care providers whether biodegradable magnesium-based implants are non-inferior to standard titanium Herbert screws for the treatment of scaphoid fractures in terms of wrist function and safety. Furthermore, superiority of magnesium-based implants may be demonstrated using MRI, which is used as surrogate endpoint for screw degradation.

Trial registration

DRKS, DRKS00013368. Registered Dec 04, 2017.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2723-9) contains supplementary material, which is available to authorized users.

A Non-inferiority Framework for Cost-Effectiveness Analysis

BACKGROUND

Traditional decision rules have limitations when a new technology is less effective and less costly than a comparator. We propose a new probabilistic decision framework to examine non-inferiority in effectiveness and net monetary benefit (NMB) simultaneously. We illustrate this framework using the example of repetitive transcranial magnetic stimulation (rTMS) and electroconvulsive therapy (ECT) for treatment-resistant depression.

METHODS

We modeled the quality-adjusted life-years (QALYs) associated with the new intervention (rTMS), an active control (ECT), and a placebo control, and we estimated the fraction of effectiveness preserved by the new intervention through probabilistic sensitivity analysis (PSA). We then assessed the probability of cost-effectiveness using a traditional cost-effectiveness acceptability curve (CEAC) and our new decision-making framework. In our new framework, we considered the new intervention cost-effective in each simulation of the PSA if it preserved at least 75 percent of the effectiveness of the active control (thus demonstrating non-inferiority) and had a positive NMB at a given willingness-to-pay threshold (WTP).

RESULTS

rTMS was less effective (i.e., associated with fewer QALYs) and less costly than ECT. The traditional CEAC approach showed that the probabilities of rTMS being cost-effective were 100 percent, 39 percent, and 14 percent at WTPs of $0, $50,000, and $100,000 per QALY gained, respectively. In the new decision framework, the probabilities of rTMS being cost-effective were reduced to 23 percent, 21 percent, and 13 percent at WTPs of $0, $50,000, and $100,000 per QALY, respectively.

CONCLUSIONS

This new framework provides a different perspective for decision making with considerations of both non-inferiority and WTP thresholds.

A multi-centre, UK-based, non-inferiority randomised controlled trial of 4 follow-up assessment methods in stroke survivors

BACKGROUND

Recovery following a stroke is a long and ongoing process. Post-stroke follow-up after leaving the hospital is recommended. Methods for follow-up patients include face-to-face, via the telephone, post or online (internet). However, there is a debate which method is preferred by patients. This study aimed to determine whether telephone interview, online questionnaire and postal questionnaire were as acceptable as face-to-face follow-up.

METHODS

In a blinded, UK-wide, multi-centre, Zelen's designed, 4-arm (postal, online, telephone, compared to face-to-face), pragmatic non-inferiority randomised controlled trial of the mode of administration, stroke survivors were randomised to postal, online, telephone and face-to-face assessment, in an equal ratio (1:1:1:1). The primary outcome was the proportion of participants that responded to the three allocation groups, compared to the face-to-face group. Subgroup analyses for age, aphasia and type and severity of stroke were carried out. A non-inferiority margin of 0.025 was used, and Holm-Bonferroni multiplicity adjustment was made.

RESULTS

Of the 2074 eligible patients randomised, 55% were male (1142/2074), with an average age of 73.0 years old (SD = 13.2). Of those randomised, 22% (116/525), 9% (47/515) and 20% (101/513) responded in postal, online and telephone, respectively, compared to 17% (89/521) in the face-to-face group. The reduction in the online response rate compared to face-to-face was found to be both inferior and not non-inferior and estimated as an 8% reduction (95% CI 3.9 to 12.0%; p < 0.001). The association with lower online completion was present regardless of age, stroke type (haemorrhage or infarct) and stroke severity. In haemorrhagic stroke, the reduction in response online, compared to face-to-face, was 21% (95% CI 10 to 32%; p value = 0.002). A secondary analysis found non-aphasic stroke survivors preferred postal completion adjusted odds ratio of 1.43 (95% CI 1.04 to 1.95; p = 0.026).

CONCLUSIONS

The study found that fewer stroke survivors completed follow-up assessment using an online method, compared to face-to-face. This finding was present in all age groups. Caution should be employed when considering online follow-up methods in stroke survivors, particularly in those who have experienced a cerebrovascular haemorrhage.

TRIALS REGISTRATION

ClinicalTrials.gov, NCT03177161 . Registered on 6 June 2017.

Preventing Childhood Anxiety Disorders: Is an Applied Game as Effective as a Cognitive Behavioral Therapy-Based Program?

A large proportion of children experience subclinical levels of anxiety and cognitive-behavioral therapy (CBT) aimed at preventing anxiety disorders is moderately effective. However, most at-risk children do not seek help or drop out of programs prematurely because of stigma, lack of motivation, and accessibility barriers. Applied games have received increased attention as viable alternatives and have shown promising results, but direct comparisons between applied games and the gold-standard CBT are lacking. Our aim was to investigate whether the applied game MindLight is as effective as CBT (i.e., Coping Cat) within an indicated prevention context. We conducted a randomized controlled non-inferiority trial with a sample of 174 children (7- to 12-year olds) with elevated levels of anxiety, comparing MindLight to CBT. Anxiety was assessed with self- and parent-reports at pre- and post-program, and at 3- and 6-month follow-ups. Intention-to-treat and completers-only confidence interval approach and latent growth curve modeling showed an overall significant quadratic decrease in child- and parent-reported anxiety symptoms over time and, as predicted, the magnitude of improvement was the same for MindLight and CBT. The within-group effect sizes were small to medium at post-test (− 0.32 to − 0.63), and medium to large (− 0.60 to − 1.07) at 3- and 6-month follow-ups. Furthermore, MindLight and CBT were rated equally anxiety inducing, difficult, and appealing; CBT was rated as more relevant to daily life than MindLight. The current study adds to the growing research on applied games for mental health and shows that these games hold potential as alternative delivery models for evidence-based therapeutic techniques.

Equal to or better than: The application of statistical non-inferiority to fatigue risk management

In December 2014, the Federal Aviation Administration (FAA) completed a major revision of the rules and regulations governing flight and duty time in commercial aviation (Federal Aviation Regulation (FAR) Part 117). Scientists were included in the revision process and provided insights into sleep, sleep loss, the circadian rhythm, and their effects on performance that were incorporated into the new rule. If a planned flight was non-compliant with the regulation, for example if it exceeded flight and duty time limits, it could only be flown under an FAA-approved Fatigue Risk Management System (FRMS) as meeting an Alternative Method of Compliance (AMOC). One method that a flight could qualify as an AMOC is if it could be demonstrated empirically that it was as safe as or safer than a similar flight, designated the Safety Standard Operation (SSO), that was compliant with the regulation. In the present paper, we demonstrate the FRMS process using a comparison between a non-compliant AMOC flight from the US west coast to Australia and a compliant SSO flight from the US west coast to Taiwan. The AMOC was non-compliant because it exceeded the flight time limits in the prescriptive rule. Once a data collection exemption was granted by the FAA, both the outbound and inbound AMOC and SSO routes were studied on four Safety Performance Indicators (SPIs). The SPIs studied were inflight sleep, cognitive performance, self-reported fatigue, and self-reported sleepiness. These measures were made at top of descent (TOD), a critical phase of flight. The study was designed as a paired comparison. Forty volunteer pilots studied flew both the AMOC and the SSO flights for a total of 80 studied flights. Using statistical non-inferiority applied to the AMOC and SSO SPIs, we demonstrated, as required by the new rule, that the US-Australia AMOC flight was "as safe as, or safer than" the US-Taiwan SSO flight. In the context of FRMS, statistical non-inferiority is a concept and technique of great utility, straightforward in application, producing clear visual representations of the findings, and providing a direct answer to the question posed by the regulation - is the AMOC flight "as safe as, or safer than" the SSO.

Comparing the new Ifakara Ambient Chamber Test with WHO cone and tunnel tests for bioefficacy and non-inferiority testing of insecticide-treated nets

BACKGROUND

Insecticide-treated net (ITN) durability, measured through physical integrity and bioefficacy, must be accurately assessed in order to plan the timely replacement of worn out nets and guide procurement of longer-lasting, cost-effective nets. World Health Organization (WHO) guidance advises that new intervention class ITNs be assessed 3 years after distribution, in experimental huts. In order to obtain information on whole-net efficacy cost-effectively and with adequate replication, a new bioassay, the Ifakara Ambient Chamber Test (I-ACT), a semi-field whole net assay baited with human host, was compared to established WHO durability testing methods.

METHODS

Two experiments were conducted using pyrethroid-susceptible female adult Anopheles gambiae sensu stricto comparing bioefficacy of Olyset®, PermaNet® 2.0 and NetProtect® evaluated by I-ACT and WHO cone and tunnel tests. In total, 432 nets (144/brand) were evaluated using I-ACT and cone test. Olyset® nets (132/144) that did not meet the WHO cone test threshold criteria (≥ 80% mortality or ≥ 95% knockdown) were evaluated using tunnel tests with threshold criteria of ≥ 80% mortality or ≥ 90% feeding inhibition for WHO tunnel and I-ACT. Pass rate of nets tested by WHO combined standard WHO bioassays (cone/tunnel tests) was compared to pass in I-ACT only by net brand and time after distribution.

RESULTS

Overall, more nets passed WHO threshold criteria when tested with I-ACT than with standard WHO bioassays 92% vs 69%, (OR: 4.1, 95% CI 3.5-4.7, p < 0.0001). The proportion of Olyset® nets that passed differed if WHO 2005 or WHO 2013 LN testing guidelines were followed: 77% vs 71%, respectively. Based on I-ACT results, PermaNet® 2.0 and NetProtect® demonstrated superior mortality and non-inferior feeding inhibition to Olyset® over 3 years of field use in Tanzania.

CONCLUSION

Ifakara Ambient Chamber Test may have use for durability studies and non-inferiority testing of new ITN products. It measures composite bioefficacy and physical integrity with both mortality and feeding inhibition endpoints, using fewer mosquitoes than standard WHO bioassays (cone and tunnel tests). The I-ACT is a high-throughput assay to evaluate ITN products that work through either contact toxicity or feeding inhibition. I-ACT allows mosquitoes to interact with a host sleeping underneath a net as encountered in the field, without risk to human participants.