The use of unequal randomisation ratios in clinical trials: a review

A protocol for a trial of homeopathic treatment for irritable bowel syndrome

Background

Irritable bowel syndrome is a chronic condition with no known cure. Many sufferers seek complementary and alternative medicine including homeopathic treatment. However there is much controversy as to the effectiveness of homeopathic treatment. This three-armed study seeks to explore the effectiveness of individualised homeopathic treatment plus usual care compared to both an attention control plus usual care and usual care alone, for patients with irritable bowel syndrome.

Methods/design

This is a three-armed pragmatic randomised controlled trial using the cohort multiple randomised trial methodology. Patients are recruited to an irritable bowel syndrome cohort from primary and secondary care using GP databases and consultants lists respectively. From this cohort patients are randomly selected to be offered, 5 sessions of homeopathic treatment plus usual care, 5 sessions of supportive listening plus usual care or usual care alone. The primary clinical outcome is the Irritable Bowel Syndrome Symptom Severity at 26 weeks.

From a power calculation, it is estimated that 33 people will be needed for the homeopathic treatment arm and 132 for the usual care arm, to detect a minimal clinical difference at 80 percent power and 5 percent significance allowing for loss to follow up. An unequal group size has been used for reasons of cost. Analysis will be by intention to treat and will compare homeopathic treatment with usual care at 26 weeks as the primary analysis, and homeopathic treatment with supportive listening as an additional analysis.

Discussion

This trial has received NHS approval and results are expected in 2013.

Trial registration

Current Controlled Trials ISRCTN90651143

Effects of motor imagery training on balance and gait abilities in post-stroke patients: a randomized controlled trial

Objectives:

To investigate the effects of motor imagery training on the balance and gait abilities of post-stroke patients.

Design:

Randomized controlled trial.

Setting:

Outpatient rehabilitation centre.

Subjects:

Twenty-eight individuals with chronic stroke.

Interventions:

The experimental group ( n = 15) performed motor imagery training involving imagining normal gait movement for 15 minutes embedded in gait training for 30 minutes (45 minutes/day, 3 times/week); the control group ( n = 13) performed gait training only (30 minutes/day, 3 times/week).

Main measures:

Balance and gait abilities were measured by the Functional Reach Test, Timed Up-and-Go Test, 10-m Walk Test and Fugl-Meyer assessment before and after interventions.

Results:

All measurements improved significantly compared with baseline values in the experimental group. In the control group, there were significant improvements in all parameters except the Fugl-Meyer assessment. All parameters of the experimental group increased significantly compared to those of the control group as follows: Functional Reach Test (control vs. experimental: 28.1 ± 3.1 vs. 37.51 ± 3.0), Timed Up-and-Go Test (20.7 ± 4.0 vs. 13.2 ± 2.2), 10-m Walk Test (17.4 ± 4.6 vs. 16.0 ± 2.7) and Fugl-Meyer assessment (12.0 ± 2.9 vs. 17.6 ± 1.3).

Conclusions:

Gait training with motor imagery training improves the balance and gait abilities of chronic stroke patients significantly better than gait training alone.

In-home preventive comprehensive geriatric assessment (CGA) reduces mortality--a randomized controlled trial

The study should prove the effectiveness of a preventive in-home CGA regarding mortality and time able to stay in the community. We performed a randomized controlled trial with a mean follow-up of 6.2 years. The home visits were performed in Germany. 1620 community-living persons aged 70 years and older (n=630 intervention; 990 controls) from 20 general practitioner surgeries were visited. The intervention was performed by trained medical students it included a CGA using the STEP-tool (standardized assessment of elderly people in primary care in Europe; a combination of a structured questionnaire and a structured physical examination) and additional tests, followed by recommendations for the general practitioner. The controls received usual general practitioner care. Follow-up visit was made at mean 6.2 years after randomization. The main outcome parameters were mortality and time able to stay at home. Follow-up-rate was 75%. In COX-regression-analyses, a 20% reduction of mortality and a 22% lower risk of nursing-home admission were shown in the intervention group at the follow up. Despite the main limitations of the study (general practitioners volunteered to participate, follow-up-rate <80%, possible performance of geriatric assessments also in the control group, intervention group had poorer health status than the control group, adherence to recommendations from the assessment was not verified) we conclude that the implementation of a preventive geriatric assessment into primary care in Germany seems to be reasonable.

Brief cognitive behavioral therapy in primary care: a hybrid type 2 patient-randomized effectiveness-implementation design

BACKGROUND

Despite the availability of evidence-based psychotherapies for depression and anxiety, they are underused in non-mental health specialty settings such as primary care. Hybrid effectiveness-implementation designs have the potential to evaluate clinical and implementation outcomes of evidence-based psychotherapies to improve their translation into routine clinical care practices.

METHODS

This protocol article discusses the study methodology and implementation strategies employed in an ongoing, hybrid, type 2 randomized controlled trial with two primary aims: (1) to determine whether a brief, manualized cognitive behavioral therapy administered by Veterans Affairs Primary Care Mental Health Integration program clinicians is effective in treating depression and anxiety in a sample of medically ill (chronic cardiopulmonary diseases) primary care patients and (2) to examine the acceptability, feasibility, and preliminary outcomes of a focused implementation strategy on improving adoption and fidelity of brief cognitive behavioral therapy at two Primary Care-Mental Health Integration clinics. The study uses a hybrid type 2 effectiveness/implementation design to simultaneously test clinical effectiveness and to collect pilot data on a multifaceted implementation strategy that includes an online training program, audit and feedback of session content, and internal and external facilitation. Additionally, the study engages the participation of an advisory council consisting of stakeholders from Primary Care-Mental Health Integration, as well as regional and national mental health leaders within the Veterans Administration. It targets recruitment of 320 participants randomized to brief cognitive behavioral therapy (n = 200) or usual care (n = 120). Both effectiveness and implementation outcomes are being assessed using mixed methods, including quantitative evaluation (e.g., intent-to-treat analyses across multiple time points) and qualitative methods (e.g., focus interviews and surveys from patients and providers). Patient-effectiveness outcomes include measures of depression, anxiety, and physical health functioning using blinded independent evaluators. Implementation outcomes include patient engagement and adherence and clinician brief cognitive behavioral therapy adoption and fidelity.

CONCLUSIONS

Hybrid designs are needed to advance clinical effectiveness and implementation knowledge to improve healthcare practices. The current article describes the rationale and challenges associated with the use of a hybrid design for the study of brief cognitive behavioral therapy in primary care. Although trade-offs exist between scientific control and external validity, hybrid designs are part of an emerging approach that has the potential to rapidly advance both science and practice.

TRIAL REGISTRATION

NCT01149772 at http://www.clinicaltrials.gov/ct2/show/NCT01149772.

Generalized multidimensional dynamic allocation method

Dynamic allocation has received considerable attention since it was first proposed in the 1970s as an alternative means of allocating treatments in clinical trials which helps to secure the balance of prognostic factors across treatment groups. The purpose of this paper is to present a generalized multidimensional dynamic allocation method that simultaneously balances treatment assignments at three key levels: within the overall study, within each level of each prognostic factor, and within each stratum, that is, combination of levels of different factors Further it offers capabilities for unbalanced and adaptive designs for trials. The treatment balancing performance of the proposed method is investigated through simulations which compare multidimensional dynamic allocation with traditional stratified block randomization and the Pocock-Simon method. On the basis of these results, we conclude that this generalized multidimensional dynamic allocation method is an improvement over conventional dynamic allocation methods and is flexible enough to be applied for most trial settings including Phases I, II and III trials.

NeoCart, an autologous cartilage tissue implant, compared with microfracture for treatment of distal femoral cartilage lesions: an FDA phase-II prospective, randomized clinical trial after two years

BACKGROUND

Despite introduction of autologous chondrocyte therapy for repair of hyaline articular cartilage injury in 1994, microfracture remains a primary standard of care. NeoCart, an autologous cartilage tissue implant, was compared with microfracture in a multisite prospective, randomized trial of a tissue-engineered bioimplant for treating articular cartilage injuries in the knee.

METHODS

Thirty patients were randomized at a ratio of two to one (two were treated with an autologous cartilage tissue implant [NeoCart] for each patient treated with microfracture) at the time of arthroscopic confirmation of an International Cartilage Repair Society (ICRS) grade-III lesion(s). Microfracture or cartilage biopsy was performed. NeoCart, produced by seeding a type-I collagen matrix scaffold with autogenous chondrocytes and bioreactor treatment, was implanted six weeks following arthroscopic cartilage biopsy. Standard evaluations were performed with validated clinical outcomes measures.

RESULTS

Three, six, twelve, and twenty-four-month data are reported. The mean duration of follow-up (and standard deviation) was 26 ± 2 months. There were twenty-one patients in the NeoCart group and nine in the microfracture group. The mean age (40 ± 9 years), body mass index (BMI) (28 ± 4 kg/m2), duration between the first symptoms and treatment (3 ± 5 years), and lesion size (287 ± 138 mm2 in the NeoCart group and 252 ± 135 mm2 in the microfracture group) were similar between the groups. Adverse event rates per procedure did not differ between the treatment arms. The scores on the Short Form-36 (SF-36), Knee Injury and Osteoarthritis Outcome Score (KOOS) activities of daily living (ADL) scale, and International Knee Documentation Committee (IKDC) form improved from baseline (p < 0.05) to two years postoperatively in both treatment groups. In the NeoCart group, improvement, compared with baseline, was significant (p < 0.05) for all measures at six, twelve, and twenty-four months. Improvement in the NeoCart group was significantly greater (p < 0.05) than that in the microfracture group for the KOOS pain score at six, twelve, and twenty-four months; the KOOS symptom score at six months; the IKDC, KOOS sports, and visual analog scale (VAS) pain scores at twelve and twenty-four months; and the KOOS quality of life (QOL) score at twenty-four months. Analysis of covariance (ANCOVA) at one year indicated that the change in the KOOS pain (p = 0.016) and IKDC (p = 0.028) scores from pretreatment levels favored the NeoCart group. Significantly more NeoCart-treated patients (p = 0.0125) had responded to therapy (were therapeutic responders) at six months (43% versus 25% in the microfracture group) and twelve months (76% versus 22% in the microfracture group). This trend continued, as the proportion of NeoCart-treated patients (fifteen of nineteen) who were therapeutic responders at twenty-four months was greater than the proportion of microfracture-treated participants (four of nine) who were therapeutic responders at that time.

CONCLUSIONS

This randomized study suggests that the safety of autologous cartilage tissue implantation, with use of the NeoCart technique, is similar to that of microfracture surgery and is associated with greater clinical efficacy at two years after treatment.

Sonographically guided intrasheath percutaneous release of the first annular pulley for trigger digits, part 2: randomized comparative study of the economic impact of 3 surgical models

OBJECTIVES

Trigger digit surgery can be performed by an open approach using classic open surgery, by a wide-awake approach, or by sonographically guided first annular pulley release in day surgery and office-based ambulatory settings. Our goal was to perform a turnover and economic analysis of 3 surgical models.

METHODS

Two studies were conducted. The first was a turnover analysis of 57 patients allocated 4:4:1 into the surgical models: sonographically guided-office-based, classic open-day surgery, and wide-awake-office-based. Regression analysis for the turnover time was monitored for assessing stability (R(2) < .26). Second, on the basis of turnover times and hospital tariff revenues, we calculated the total costs, income to cost ratio, opportunity cost, true cost, true net income (primary variable), break-even points for sonographically guided fixed costs, and 1-way analysis for identifying thresholds among alternatives.

RESULTS

Thirteen sonographically guided-office-based patients were withdrawn because of a learning curve influence. The wide-awake (n = 6) and classic (n = 26) models were compared to the last 25% of the sonographically guided group (n = 12), which showed significantly less mean turnover times, income to cost ratios 2.52 and 10.9 times larger, and true costs 75.48 and 20.92 times lower, respectively. A true net income break-even point happened after 19.78 sonographically guided-office-based procedures. Sensitivity analysis showed a threshold between wide-awake and last 25% sonographically guided true costs if the last 25% sonographically guided turnover times reached 65.23 and 27.81 minutes, respectively. However, this trial was underpowered.

CONCLUSIONS

This trial comparing surgical models was underpowered and is inconclusive on turnover times; however, the sonographically guided-office-based approach showed shorter turnover times and better economic results with a quick recoup of the costs of sonographically assisted surgery.

Betamethasone dosing interval: 12 or 24 hours apart? A randomized, noninferiority open trial

OBJECTIVE

We sought to determine whether the incidence of neonatal respiratory distress syndrome (RDS) is similar with 12- vs 24-hour dosing interval of betamethasone.

STUDY DESIGN

This was a prospective, randomized, open, noninferiority trial. Mothers (n = 228) with a singleton or multiple pregnancies (fetuses = 260), between gestational age of 23-34 weeks, at risk for preterm delivery, received standard 2 doses of betamethasone either 12 or 24 hours apart in 2:1 ratio, respectively.

RESULTS

Incidence of RDS was similar in the 2 cohorts (36.5% vs 37.3%; P = not significant). Women unable to receive the complete course of corticosteroids with the 24-hour interval can be reduced by half with the 12-hour interval. However, increased incidence of necrotizing enterocolitis was seen with 12-hour dosing (6.2% vs 0%; P = .03).

CONCLUSION

The 12-hour dosing interval is equivalent to the 24-hour dosing interval for prevention of RDS in neonates of mothers delivering prematurely. A larger multicenter study is needed to confirm our findings.

Optical coherence tomography compared with colposcopy for assessment of vaginal epithelial damage: a randomized controlled trial

OBJECTIVE

Colposcopy has been used to detect epithelial damage with vaginal microbicides. In animal models, optical coherence tomography provided increased sensitivity over colposcopy in detecting epithelial injury. This randomized, double-blinded, clinical study compared optical coherence tomography to colposcopy for the evaluation of epithelial injury in women using placebo or nonoxynol-9.

METHODS

Thirty women aged 18-45 were randomized to use hydroxyethyl cellulose placebo or nonoxynol-9 vaginal gel twice daily for 5.5 days. Imaging with colposcopy and optical coherence tomography was performed before product use, after the last dose, and 1 week later. Colposcopy was graded using standard criteria. Optical coherence tomography images were scored for epithelial integrity based on a published scoring system and were measured for epithelial thickness.

RESULTS

Colposcopy findings, optical coherence tomography scores, and epithelial thicknesses were similar between treatment groups at baseline. After treatment, there were significant differences between the nonoxynol-9 (1.37) and control group (1.15) optical coherence tomography scores (P<.001), indicating epithelial injury, and there was epithelial thinning in the nonoxynol-9 group (237 micrometers) compared with the control group (292 micrometers; P=.008). There were no significant posttreatment colposcopic differences in epithelial disruption between treatment groups, with only increased erythema noted after nonoxynol-9 use (P=.02).

CONCLUSION

Optical coherence tomography detected epithelial disruption and thinning not identified by colposcopy. Vaginal epithelial thickness, a measure previously available only through biopsy, decreased after nonoxynol-9 use, a finding that may contribute to increased susceptibility to human immunodeficiency virus after frequent use. Optical coherence tomography shows promise for the noninvasive clinical assessment of vaginal epithelial damage.

CLINICAL TRIAL REGISTRATION

UMIN Clinical Trials Registry, www.umin.ac.jp/ctr/index.htm, R000006186.

LEVEL OF EVIDENCE

I.

Telephone-administered motivational interviewing reduces risky sexual behavior in HIV-positive late middle-age and older adults: a pilot randomized controlled trial

By 2014, 50% of all adults living with HIV/AIDS will be 50-plus years of age. This pilot randomized controlled trial assessed the efficacy of two telephone-delivered motivational interviewing (MI) interventions to reduce risky sexual behavior in HIV-infected adults 45-plus years old. Eligible participants reported engaging in at least one occasion of unprotected anal and/or vaginal intercourse in the 3 months prior to study enrollment. Participants were randomly assigned to receive four sessions of telephone-delivered MI, one session of telephone-delivered MI, or no MI. Relative to 4-session MI participants, Controls reported approximately three times as many episodes of unprotected sex at 3- and 6-month follow-up, while 1-session MI participants reported four times as many unprotected sex acts at 3- and 6-month follow-up. No differences in condom use were observed between 1-session MI and Control participants. Additional large-scale studies that evaluate this intervention approach are warranted.

Randomized treatment-belief trials

It is widely recognized that traditional randomized controlled trials (RCTs) have limited generalizability due to the numerous ways in which conditions of RCTs differ from those experienced each day by patients and physicians. As a result, there has been a recent push towards pragmatic trials that better mimic real-world conditions. One way in which RCTs differ from normal everyday experience is that all patients in the trial have uncertainty about what treatment they were assigned. Outside of the RCT setting, if a patient is prescribed a drug then there is no reason for them to wonder if it is a placebo. Uncertainty about treatment assignment could affect both treatment and placebo response. We use a potential outcomes approach to define relevant causal effects based on combinations of treatment assignment and belief about treatment assignment. We show that traditional RCTs are designed to estimate a quantity that is typically not of primary interest. We propose a new study design that has the potential to provide information about a wider range of interesting causal effects.

Cost-effectiveness of a lifestyle intervention in preventing Type 2 diabetes

OBJECTIVES

Previous research has suggested people with impaired fasting glucose (IFG) are less likely to develop Type 2 diabetes (T2DM) if they receive prolonged structured diet and exercise advice. This study examined the within-trial cost-effectiveness of such lifestyle interventions.

METHODS

Screen-detected participants with either newly diagnosed T2DM or IFG were randomized 2:1 to intervention versus control (usual care) between February and December 2009, in Norfolk (UK). The intervention consisted of group based education, physiotherapy and peer support sessions, plus telephone contacts from T2DM volunteers. We monitored healthcare resource use, intervention costs, and quality of life (EQ-5D). The incremental cost per quality-adjusted life-year (QALY) gain (incremental cost effectiveness ratio [ICER]), and cost effectiveness acceptability curves (CEAC) were estimated.

RESULTS

In total, 177 participants were recruited (118 intervention, 59 controls), with a mean follow-up of 7 months. Excluding screening and recruitment costs, the mean cost was estimated to be £551 per participant in the intervention arm, compared with £325 in the control arm. The QALY gains were -0.001 and -0.004, respectively. The intervention was estimated to have an ICER of £67,184 per QALY (16 percent probability of being cost-effective at the £20,000/QALY threshold). Cost-effectiveness estimates were more favorable for IFG participants and those with longer follow-up (≥ 4 months) (ICERs of £20,620 and £17,075 per QALY, respectively).

CONCLUSIONS

Group sessions to prevent T2DM were not estimated to be within current limits of cost-effectiveness. However, there was a large degree of uncertainty surrounding these estimates, suggesting the need for further research.

Meta-analysis of passive immunoprophylaxis in paediatric patients at risk of severe RSV infection

AIM

To review respiratory syncytial virus (RSV), passive immunoprophylaxis (PI) trials and meta-analysis (MA).

METHODS

A literature review.

RESULTS

Two MA of PI were found. Overall 3927 patients were randomized. PI reduces RSV hospitalization in patients with bronchopulmonary dysplasia (RR 0.58; 95% CI 0.41, 0.82) and with acyanotic congenital heart disease (RR 0.29; 95% CI 0.14, 0.62). In patients with cyanotic heart disease or premature infants without bronchopulmonary dysplasia, results are inconclusive. Passive immunoprophylaxis has a null effect in mechanical ventilation and death.

CONCLUSION

Passive immunoprophylaxis reduces RSV hospitalization in a subset of patients. However, it has no effect in harder endpoints of RSV disease severity.

Problems of randomization to open or laparoscopic sigmoidectomy for diverticular disease

PURPOSE

Although complicated sigmoid diverticulitis is the most common reason for laparoscopic sigmoidectomy, the level of evidence for preference of the laparoscopic approach is low.

METHODS

A multicenter, randomized clinical trial comparing laparoscopic and open sigmoidectomy for diverticulitis was conducted to evaluate the short- and mid-term outcome after both techniques. Data were assessed from randomized patients and from patients who refused randomization. Results of the here presented interim analysis describe the difficulties in randomization leading to abortion of recruitment.

RESULTS

149 patients were enrolled in the randomized trial within 36 months until the interim analysis. A further 294 nonrandomized patients who preferred one of both surgical approaches were assessed. Several differences between these groups were apparent including simple epidemiological characteristics such as age (65 vs. 60 years, p < 0.001), gender (65% vs. 55% female, p = 0.05), BMI (27 vs. 26 kg/m(2), p = 0.01), and ASA class < III (72% vs. 87%, p < 0.001).

CONCLUSION

The majority of eligible patients refused a random allocation. A widespread presumption of the advantages of laparoscopic surgery was probably the main reason for refusal. Patients participating in randomization did not reflect the general population in recruiting hospitals. Future trials comparing minimal invasive procedures should be conducted before presumptions concerning the outcome are widespread in the general population.

Generalized method for adaptive randomization in clinical trials

A flexible, generalized method of treatment allocation is proposed. The method uses a set of controlling parameters that enables the generic algorithm to produce a family of possible outcomes ranging from simple randomization to deterministic allocation. The method controls balance at stratum level, stratification level and overall without detriment to the predictability of the method. The paper lists the desirable characteristics of allocation methods and shows that the proposed method fulfils the majority and is easy to use in the clinical context, once the coding has been established. An explanation of the method for 2, 3 and 4 treatment group allocations is given. Simulations demonstrate the flexibility of the method.

Randomized transcoronary delivery of CD34(+) cells with perfusion versus stop-flow method in patients with recent myocardial infarction: Early cardiac retention of ⁹⁹(m)Tc-labeled cells activity

BACKGROUND

For transcoronary progenitor cells' administration, injections under flow arrest (over-the-wire balloon technique, OTW) are used universally despite lack of evidence for being required for cell delivery or being effective in stimulating myocardial engraftment. Flow-mediated endothelial rolling is mandatory for subsequent cell adhesion and extravasation.

METHODS

To optimize cell directing toward the coronary endothelium under maintained flow, the authors developed a cell-delivery side-holed perfusion catheter (PC). Thirty-four patients (36-69 years, 30 men) with primary stent-assisted angioplasty-treated anterior MI (peak TnI 151 [53-356]ng/dL, mean[range]) were randomly assigned to OTW or PC autologous ⁹⁹Tc-extametazime-labeled bone marrow CD34(+) cells (4.34 [0.92-7.54] × 10⁶) administration at 6-14 days after pPCI (LVEF 37.1 [24-44]%). Myocardial perfusion (⁹⁹(m)Tc-MIBI) and labeled cells' activity were evaluated (SPECT) at, respectively, 36-48 h prior to and 60 min after delivery.

RESULTS

In contrast to OTW coronary occlusions, no intolerance or ventricular arrhythmia occurred with PC cells' administration (P < .001). One hour after delivery, 4.86 [1.7-7.6]% and 5.05 [2.2-9.9]% activity was detected in the myocardium (OTW and PC, respectively, P = .84). Labeled cell activity was clearly limited to the (viable) peri-infarct zone in 88% patients, indicating that the infarct core zone may be largely inaccessible to transcoronary-administered cells.

CONCLUSIONS

Irrespective of the transcoronary delivery method, only ≈ 5% of native (i.e., non-engineered) CD34(+) cells spontaneously home to the injured myocardium, and cell retention occurs preferentially in the viable peri-infarct zone. Although the efficacy of cell delivery is not increased with the perfusion method, by avoiding provoking ischemic episodes PC offers a rational alternative to the OTW delivery.

A behavioural Bayes approach to the determination of sample size for clinical trials considering efficacy and safety: imbalanced sample size in treatment groups

The behavioural Bayes approach to sample size determination for clinical trials assumes that the number of subsequent patients switching to a new drug from the current drug depends on the strength of the evidence for efficacy and safety that was observed in the clinical trials. The optimal sample size is the one which maximises the expected net benefit of the trial. The approach has been developed in a series of papers by Pezeshk and the present authors (Gittins JC, Pezeshk H. A behavioral Bayes method for determining the size of a clinical trial. Drug Information Journal 2000; 34: 355-63; Gittins JC, Pezeshk H. How Large should a clinical trial be? The Statistician 2000; 49(2): 177-87; Gittins JC, Pezeshk H. A decision theoretic approach to sample size determination in clinical trials. Journal of Biopharmaceutical Statistics 2002; 12(4): 535-51; Gittins JC, Pezeshk H. A fully Bayesian approach to calculating sample sizes for clinical trials with binary responses. Drug Information Journal 2002; 36: 143-50; Kikuchi T, Pezeshk H, Gittins J. A Bayesian cost-benefit approach to the determination of sample size in clinical trials. Statistics in Medicine 2008; 27(1): 68-82; Kikuchi T, Gittins J. A behavioral Bayes method to determine the sample size of a clinical trial considering efficacy and safety. Statistics in Medicine 2009; 28(18): 2293-306; Kikuchi T, Gittins J. A Bayesian procedure for cost-benefit evaluation of a new drug in multi-national clinical trials. Statistics in Medicine 2009 (Submitted)). The purpose of this article is to provide a rationale for experimental designs which allocate more patients to the new treatment than to the control group. The model uses a logistic weight function, including an interaction term linking efficacy and safety, which determines the number of patients choosing the new drug, and hence the resulting benefit. A Monte Carlo simulation is employed for the calculation. Having a larger group of patients on the new drug in general makes it easier to recruit patients to the trial and may also be ethically desirable. Our results show that this can be done with very little if any reduction in expected net benefit.

Preliminary effects of bupropion and the promoter region (HTTLPR) serotonin transporter (SLC6A4) polymorphism on smoking behavior in schizophrenia

In the current study, we investigated how individual variants in the serotonin promoter gene, previously associated with smoking cessation and linked to anxiety-related personality traits, were associated with individual differences in responsiveness to bupropion and cognitive behavioral therapy (CBT) in a clinical population. We hypothesize that subjects with the long allele may be less responsive to treatment. Altogether 61 schizophrenic patients (46 M, 15 F) on stable neuroleptic medication were initially enrolled in a smoking reduction program (prospective, double-blind, placebo-controlled) including cognitive behavioral therapy plus placebo or CBT plus bupropion. Additionally, subjects were genotyped for a polymorphism in the serotonin transporter (SLC6A4). Thirty-two subjects (23 M, 9 F) completed a 14-week course of treatment. While both groups of subjects demonstrated significant reductions in smoking behavior due to CBT, subjects receiving bupropion did not show significant differences in smoking behavior when compared to placebo. In addition, analysis by SPSS repeated measures multivariate showed a significant sex by SLC6A4 genotype interaction on the number of cigarettes smoked. Only male subjects with at least one short promoter region allele (short/short and short/long combined) showed a reduction in cigarette consumption as a result of treatment. This study provides preliminary evidence of how polymorphisms in the serotonin transporter can be informative in predicting individual responses to smoking reduction therapy.

Argemone mexicana decoction versus artesunate-amodiaquine for the management of malaria in Mali: policy and public-health implications

A classic way of delaying drug resistance is to use an alternative when possible. We tested the malaria treatment Argemone mexicana decoction (AM), a validated self-prepared traditional medicine made with one widely available plant and safe across wide dose variations. In an attempt to reflect the real situation in the home-based management of malaria in a remote Malian village, 301 patients with presumed uncomplicated malaria (median age 5 years) were randomly assigned to receive AM or artesunate-amodiaquine [artemisinin combination therapy (ACT)] as first-line treatment. Both treatments were well tolerated. Over 28 days, second-line treatment was not required for 89% (95% CI 84.1-93.2) of patients on AM, versus 95% (95% CI 88.8-98.3) on ACT. Deterioration to severe malaria was 1.9% in both groups in children aged </=5 years (there were no cases in patients aged >5 years) and 0% had coma/convulsions. AM, now government-approved in Mali, could be tested as a first-line complement to standard modern drugs in high-transmission areas, in order to reduce the drug pressure for development of resistance to ACT, in the management of malaria. In view of the low rate of severe malaria and good tolerability, AM may also constitute a first-aid treatment when access to other antimalarials is delayed.

The net effect of alternative allocation ratios on recruitment time and trial cost

BACKGROUND

Increasing the proportion of subjects allocated to the experimental treatment in controlled clinical trials is often advocated as a method of increasing recruitment rates and improving the performance of trials. The presumption is that the higher likelihood of randomization to the experimental treatment will be perceived by potential study enrollees as an added benefit of participation and will increase recruitment rates and speed the completion of trials. However, studies with alternative allocation ratios require a larger sample size to maintain statistical power, which may result in a net increase in time required to complete recruitment and a net increase in total trial cost.

PURPOSE

To describe the potential net effect of alternative allocation ratios on recruitment time and trial cost.

METHODS

Models of recruitment time and trial cost were developed and used to compare trials with 1:1 allocation to trials with alternative allocation ratios under a range of per subject costs, per day costs, and enrollment rates.

RESULTS

In regard to time required to complete recruitment, alternative allocation ratios are net beneficial if the recruitment rate improves by more than about 4% for trials with a 1.5:1 allocation ratio and 12% for trials with a 2:1 allocation ratio. More substantial improvements in recruitment rate, 13 and 47% respectively for scenarios we considered, are required for alternative allocation to be net beneficial in terms of tangible monetary cost.

LIMITATIONS

The cost models were developed expressly for trials comparing proportions or means across treatment groups.

CONCLUSIONS

Using alternative allocation ratio designs to improve recruitment may or may not be time and cost-effective. Using alternative allocation for this purpose should only be considered for trial contexts where there is both clear evidence that the alternative design does improve recruitment rates and the attained time or cost efficiency justifies the added study subject burden implied by a larger sample size.

The impact of a self-management group programme on health behaviour and healthcare utilization among congestive heart failure patients

AIMS

The 'Chronic Disease Self-Management Programme' (CDSMP) emphasizes patients' responsibility for the day-to-day management of their condition(s) and has shown favourable effects on health behaviour and healthcare utilization among various groups of patients with chronic conditions. However, the effects of the CDSMP among congestive heart failure (CHF) patients are unknown. We therefore aimed to assess the effects of the CDSMP on health behaviour and healthcare utilization in patients with CHF.

METHODS AND RESULTS

This randomized, controlled trial with 12 months of follow-up included 317 CHF patients with a slight to marked limitation of physical activity. Control patients (n = 131) received usual care, consisting of regular checkups at an outpatient clinic. Intervention group patients (n = 186) received usual care and participated in a 6-week self-management group programme. Favourable effects on walking for exercise and other physical activities such as aerobic, stretching, and strength exercises, sports, and gardening were reported in the intervention group immediately after completion of the programme. The effect of the programme on other physical activities extended to 6 months of follow-up. No favourable effects were found for the other outcomes.

CONCLUSION

The CDSMP significantly improved physical activity among CHF patients for up to 6 months after the end of the programme; however, it did not affect other health behaviour outcomes or healthcare utilization.

Promoting abstinence from cocaine and heroin with a methadone dose increase and a novel contingency

To test whether a combination of contingency management and methadone dose increase would promote abstinence from heroin and cocaine, we conducted a randomized controlled trial using a 2 x 3 (dosexcontingency) factorial design in which dose assignment was double-blind. Participants were 252 heroin- and cocaine-abusing outpatients on methadone maintenance. They were randomly assigned to methadone dose (70 or 100mg/day, double-blind) and voucher condition (noncontingent, contingent on cocaine-negative urines, or "split"). The "split" contingency was a novel contingency that reinforced abstinence from either drug while doubly reinforcing simultaneous abstinence from both: the total value of incentives was "split" between drugs to contain costs. The main outcome measures were percentages of urine specimens negative for heroin, cocaine, and both simultaneously; these were monitored during a 5-week baseline of standard treatment (to determine study eligibility), a 12-week intervention, and a 10-week maintenance phase (to examine intervention effects in return-to-baseline conditions). DSM-IV criteria for ongoing drug dependence were assessed at study exit. Urine-screen results showed that the methadone dose increase reduced heroin use but not cocaine use. The split 100mg group was the only group to achieve a longer duration of simultaneous negatives than its same-dose noncontingent control group. The frequency of DSM-IV opiate and cocaine dependence diagnoses decreased in the active intervention groups. For a split contingency to promote simultaneous abstinence from cocaine and heroin, a relatively high dose of methadone appears necessary but not sufficient; an increase in overall incentive amount may also be required.

Optimum treatment allocation rules under a variance heterogeneity model

We provide optimal treatment allocation schemes when the outcome variance varies across the treatment groups and our objectives are to estimate treatment effects with equal or unequal interest. Unlike other optimal designs, such as A-optimal designs, the proposed designs can be found without an iterative scheme. We evaluate robustness properties of the optimal designs to mis-specification in the expected variance from each group and identify situations when popular allocation schemes have poor efficiencies. An application to design a randomized rheumatoid arthritis trial is discussed, along with a potential application to design a cancer screening trial when the main outcome is a continuous variable.

Just-in-time information improved decision-making in primary care: a randomized controlled trial

BACKGROUND

The "Just-in-time Information" (JIT) librarian consultation service was designed to provide rapid information to answer primary care clinical questions during patient hours. This study evaluated whether information provided by librarians to answer clinical questions positively impacted time, decision-making, cost savings and satisfaction.

METHODS AND FINDING

A randomized controlled trial (RCT) was conducted between October 2005 and April 2006. A total of 1,889 questions were sent to the service by 88 participants. The object of the randomization was a clinical question. Each participant had clinical questions randomly allocated to both intervention (librarian information) and control (no librarian information) groups. Participants were trained to send clinical questions via a hand-held device. The impact of the information provided by the service (or not provided by the service), additional resources and time required for both groups was assessed using a survey sent 24 hours after a question was submitted. The average time for JIT librarians to respond to all questions was 13.68 minutes/question (95% CI, 13.38 to 13.98). The average time for participants to respond their control questions was 20.29 minutes/question (95% CI, 18.72 to 21.86). Using an impact assessment scale rating cognitive impact, participants rated 62.9% of information provided to intervention group questions as having a highly positive cognitive impact. They rated 14.8% of their own answers to control question as having a highly positive cognitive impact, 44.9% has having a negative cognitive impact, and 24.8% with no cognitive impact at all. In an exit survey measuring satisfaction, 86% (62/72 responses) of participants scored the service as having a positive impact on care and 72% (52/72) indicated that they would use the service frequently if it were continued.

CONCLUSIONS

In this study, providing timely information to clinical questions had a highly positive impact on decision-making and a high approval rating from participants. Using a librarian to respond to clinical questions may allow primary care professionals to have more time in their day, thus potentially increasing patient access to care. Such services may reduce costs through decreasing the need for referrals, further tests, and other courses of action.

TRIAL REGISTRATION

Controlled-Trials.com ISRCTN96823810.

Self-report of illicit benzodiazepine use on the Addiction Severity Index predicts treatment outcome

The relationship between pre-treatment illicit benzodiazepine use (days of use in the last 30) assessed on the Addiction Severity Index (ASI) and treatment outcome was investigated by retrospective analysis of data from two controlled clinical trials in 361 methadone maintained cocaine/opiate users randomly assigned to 12-week voucher- or prize-based contingency management (CM) or control interventions. Based on screening ASI, participants were identified as non-users (BZD-N; 0 days of use) or users (BZD-U; >0 days of use). Outcome measures were: urine drug screens (thrice weekly); quality of life and self-reported HIV-risk behaviors (every 2 weeks); and current DSM-IV diagnosis of cocaine and heroin dependence (study exit). In the CM group, BZD-U had significantly worse outcomes on in-treatment cocaine use, quality-of-life scores, needle-sharing behaviors, and current heroin dependence diagnoses at study exit compared to BZD-N. In the control group, BZD-U had significantly higher in-treatment cocaine use but did not differ from BZD-N on psychosocial measures. Thus, in a sample of non-dependent BZD users, self-reported illicit BZD use on the ASI, even at low levels, predicted worse outcome on cocaine use and blunted response to CM.

The effect of patient choice of intervention on health outcomes

BACKGROUND

Patient preference may influence intervention effects, but has not been extensively studied. Randomized controlled design (N=1075) assessed outcomes when women (60 years+) were given a choice of two formats of a program to enhance heart disease management.

METHODS

Randomization to "no choice" or "choice" study arms. Further randomization of "no choice" to: 1) Group intervention program format, 2) Self-Directed program format, 3) Control Group. "Choice" arm selected their preferred program format. Baseline, four, twelve, and eighteen month follow-up data were collected. Two analyses: health outcomes for choice compared to being randomized; and preference effect on treatment efficacy.

RESULTS

Women who chose a format compared to being assigned a format had better psychosocial functioning at four months (p=0.02) and tended toward better physical functioning at twelve months (p=0.07). At eighteen months women who chose versus being assigned a format had more symptoms measured as: number (p=0.004), frequency (p=0.006) and bother (p=0.004). At four months women who preferred the Group format had better psychosocial functioning when assigned the Group format than when they were assigned the Self-Directed format (p=0.03). At eighteen months women preferring a Group format had more symptoms: number (p=0.001), frequency (p=0.001), bother (p=0.001) when assigned the Group format than when assigned the Self-Directed format.

CONCLUSIONS

Choice and preference for the Group format each enhanced psychosocial and physical functioning up to one year. Despite the preference for Group format, over the longer term (eighteen months) cardiac symptoms were fewer when assigned the Self-Directed format.

A guide to planning and executing a surgical randomized controlled trial

Evidence-based medicine requires that treatments given to patients demonstrate effectiveness. The randomized controlled trial (RCT) has become the preeminent study design to assess the efficacy of treatments. Randomized controlled trials are frequently used to evaluate pharmaceutical treatments but are less often used in surgery. The lack of surgical RCTs is partly due to ethical and methodological concerns associated with surgical interventions. We provide a guide to planning and conducting a surgical RCT.

Psychosocial functioning and cocaine use during treatment: strength of relationship depends on type of urine-testing method

Although improvement in psychosocial functioning is a common goal in substance-abuse treatment, the primary outcome measure in most cocaine trials is urinalysis-verified cocaine use. However, the relationship between cocaine use and psychosocial outcomes is not well documented. To investigate this relationship and identify the optimal urine-screen method, we retrospectively analyzed data from two 25-week randomized controlled trials of abstinence reinforcement (AR) in 368 cocaine/heroin users maintained on methadone. Cocaine use was measured thrice weekly by qualitative urinalysis, benzoylecgonine concentration (BE), and an estimate of New Uses of cocaine by application of an algorithm to BE. Social adjustment (SAS-SR), current diagnosis of cocaine dependence (DSM-IV criteria), and depression symptoms (Beck Depression Inventory) were determined at study exit. Cocaine use was significantly lower in AR groups than in controls. Across groups, in-treatment cocaine use was significantly associated with worse social adjustment, current cocaine dependence, and depression at exit. Significant differences were detected more frequently with New Uses than qualitative urinalysis or BE. Nevertheless, the amount of variance accounted for by the urine screens was typically <15%. Cocaine use during treatment, especially when measured with New Uses criteria, can predict psychosocial functioning, but cannot substitute for direct measures of psychosocial functioning.