Should the two-trial paradigm still be the gold standard in drug assessment?

Two significant pivotal trials are usually required for a new drug approval by a regulatory agency. This standard requirement is known as the two-trial paradigm. However, several authors have questioned why we need exactly two pivotal trials, what statistical error the regulators are trying to protect against, and potential alternative approaches. Therefore, it is important to investigate these questions to better understand the regulatory decision-making in the assessment of drugs' effectiveness. It is common that two identically designed trials are run solely to adhere to the two-trial rule. Previous work showed that combining the data from the two trials into a single trial (one-trial paradigm) would increase the power while ensuring the same level of type I error protection as the two-trial paradigm. However, this is true only under a specific scenario and there is little investigation on the type I error protection over the whole null region. In this article, we compare the two paradigms by considering scenarios in which the two trials are conducted in identical or different populations as well as with equal or unequal size. With identical populations, the results show that a single trial provides better type I error protection and higher power. Conversely, with different populations, although the one-trial rule is more powerful in some cases, it does not always protect against the type I error. Hence, there is the need for appropriate flexibility around the two-trial paradigm and the appropriate approach should be chosen based on the questions we are interested in.

Group sequential designs in pragmatic trials: feasibility and assessment of utility using data from a number of recent surgical RCTs.

BACKGROUND: Assessing the long term effects of many surgical interventions tested in pragmatic RCTs may require extended periods of participant follow-up to assess effectiveness and use patient-reported outcomes that require large sample sizes. Consequently the RCTs are often perceived as being expensive and time-consuming, particularly if the results show the test intervention is not effective. Adaptive, and particularly group sequential, designs have great potential to improve the efficiency and cost of testing new and existing surgical interventions. As a means to assess the potential utility of group sequential designs, we re-analyse data from a number of recent high-profile RCTs and assess whether using such a design would have caused the trial to stop early. METHODS: Many pragmatic RCTs monitor participants at a number of occasions (e.g. at 6, 12 and 24 months after surgery) during follow-up as a means to assess recovery and also to keep participants engaged with the trial process. Conventionally one of the outcomes is selected as the primary (final) outcome, for clinical reasons, with others designated as either early or late outcomes. In such settings, novel group sequential designs that use data from not only the final outcome but also from early outcomes at interim analyses can be used to inform stopping decisions. We describe data from seven recent surgical RCTs (WAT, DRAFFT, WOLLF, FASHION, CSAW, FIXDT, TOPKAT), and outline possible group sequential designs that could plausibly have been proposed at the design stage. We then simulate how these group sequential designs could have proceeded, by using the observed data and dates to replicate how information could have accumulated and decisions been made for each RCT. RESULTS: The results of the simulated group sequential designs showed that for two of the RCTs it was highly likely that they would have stopped for futility at interim analyses, potentially saving considerable time (15 and 23 months) and costs and avoiding patients being exposed to interventions that were either ineffective or no better than standard care. We discuss the characteristics of RCTs that are important in order to use the methodology we describe, particularly the value of early outcomes and the window of opportunity when early stopping decisions can be made and how it is related to the length of recruitment period and follow-up. CONCLUSIONS: The results for five of the RCTs tested showed that group sequential designs using early outcome data would have been feasible and likely to provide designs that were at least as efficient, and possibly more efficient, than the original fixed sample size designs. In general, the amount of information provided by the early outcomes was surprisingly large, due to the strength of correlations with the primary outcome. This suggests that the methods described here are likely to provide benefits more generally across the range of surgical trials and more widely in other application areas where trial designs, outcomes and follow-up patterns are structured and behave similarly.

Biased Survival Predictions When Appraising Health Technologies in Heterogeneous Populations.

INTRODUCTION: Time-to-event data from clinical trials are routinely extrapolated using parametric models to estimate the cost effectiveness of novel therapies, but how this approach performs in the presence of heterogeneous populations remains unknown. METHODS: We performed a simulation study of seven scenarios with varying exponential distributions modelling treatment and prognostic effects across subgroup and complement populations, with follow-up typical of clinical trials used to appraise the cost effectiveness of therapies by agencies such as the UK National Institute for Health and Care Excellence (NICE). We compared established and emerging methods of estimating population life-years (LYs) using parametric models. We also proved analytically that an exponential model fitted to censored heterogeneous survival times sampled from two distinct exponential distributions will produce a biased estimate of the hazard rate and LYs. RESULTS: LYs are underestimated by the methods in the presence of heterogeneity, resulting in either under- or overestimation of the incremental benefit. In scenarios where the overestimation of benefit is likely, which is of interest to the healthcare provider, the method of taking the average LYs from all plausible models has the least bias. LY estimates from complete Kaplan-Meier curves have high variation, suggesting mature data may not be a reliable solution. We explore the effect of increasing trial sample size and accounting for detected treatment-subgroup interactions. CONCLUSIONS: The bias associated with heterogeneous populations suggests that NICE may need to be more cautious when appraising therapies and to consider model averaging or the separate modelling of subgroups when heterogeneity is suspected or detected.

Development of a model to demonstrate the impact of National Institute of Health and Care Excellence cost-effectiveness assessment on health utility for targeted medicines.

Advances in medical technology have led to a better understanding of heterogeneity of diseases and patients, and to the development of targeted medicines. This development is beneficial to society but can come at an increased cost to pharmaceutical manufacturers due to the costs associated with developing and manufacturing a diagnostic test. For such medicines, the conventional pricing structure, where a therapy is approved if it is deemed cost-effective, may not appropriately incentivize targeted drug development. We model the decision-making processes for both the healthcare provider and the pharmaceutical manufacturer, capturing their main priorities, and populate it with information from a recent appraisal by the National Institute of Health and Care Excellence. Healthcare providers prefer a stratified drug to be developed for a subgroup of the population when the drug is on average effective in the subgroup but with a detrimental effect in the complement. Whilst pharmaceutical manufacturers' preferences are similar, regions of disagreement exist. We show how preferences can be aligned by either penalizing the development of a non-stratified drug or rewarding the development of a stratified drug. The cost and position of alignment depends on the true value of health to the healthcare provider, among other parameters.

Extrapolating Parametric Survival Models in Health Technology Assessment Using Model Averaging: A Simulation Study.

Previous work examined the suitability of relying on routine methods of model selection when extrapolating survival data in a health technology appraisal setting. Here we explore solutions to improve reliability of restricted mean survival time (RMST) estimates from trial data by assessing model plausibility and implementing model averaging. We compare our previous methods of selecting a model for extrapolation using the Akaike information criterion (AIC) and Bayesian information criterion (BIC). Our methods of model averaging include using equal weighting across models falling within established threshold ranges for AIC and BIC and using BIC-based weighted averages. We apply our plausibility assessment and implement model averaging to the output of our previous simulations, where 10,000 runs of 12 trial-based scenarios were examined. We demonstrate that removing implausible models from consideration reduces the mean squared error associated with the restricted mean survival time (RMST) estimate from each selection method and increases the percentage of RMST estimates that were within 10% of the RMST from the parameters of the sampling distribution. The methods of averaging were superior to selecting a single optimal extrapolation, aside from some of the exponential scenarios where BIC already selected the exponential model. The averaging methods with wide criterion-based thresholds outperformed BIC-weighted averaging in the majority of scenarios. We conclude that model averaging approaches should feature more widely in the appraisal of health technologies where extrapolation is influential and considerable uncertainty is present. Where data demonstrate complicated underlying hazard rates, funders should account for the additional uncertainty associated with these extrapolations in their decision making. Extended follow-up from trials should be encouraged and used to review prices of therapies to ensure a fair price is paid.

Extrapolating Parametric Survival Models in Health Technology Assessment: A Simulation Study.

Extrapolations of parametric survival models fitted to censored data are routinely used in the assessment of health technologies to estimate mean survival, particularly in diseases that potentially reduce the life expectancy of patients. Akaike's information criterion (AIC) and Bayesian information criterion (BIC) are commonly used in health technology assessment alongside an assessment of plausibility to determine which statistical model best fits the data and should be used for prediction of long-term treatment effects. We compare fit and estimates of restricted mean survival time (RMST) from 8 parametric models and contrast models preferred in terms of AIC, BIC, and log-likelihood, without considering model plausibility. We assess the methods' suitability for selecting a parametric model through simulation of data replicating the follow-up of intervention arms for various time-to-event outcomes from 4 clinical trials. Follow-up was replicated through the consideration of recruitment duration and minimum and maximum follow-up times. Ten thousand simulations of each scenario were performed. We demonstrate that the different methods can result in disagreement over the best model and that it is inappropriate to base model selection solely on goodness-of-fit statistics without consideration of hazard behavior and plausibility of extrapolations. We show that typical trial follow-up can be unsuitable for extrapolation, resulting in unreliable estimation of multiple parameter models, and infer that selecting survival models based only on goodness-of-fit statistics is unsuitable due to the high level of uncertainty in a cost-effectiveness analysis. This article demonstrates the potential problems of overreliance on goodness-of-fit statistics when selecting a model for extrapolation. When follow-up is more mature, BIC appears superior to the other selection methods, selecting models with the most accurate and least biased estimates of RMST.

Protocol for a randomised controlled trial of Subacromial spacer for Tears Affecting Rotator cuff Tendons: a Randomised, Efficient, Adaptive Clinical Trial in Surgery (START:REACTS).

INTRODUCTION: Shoulder pain due to irreparable rotator cuff tears can cause substantial disability, but treatment options are limited. A balloon spacer is a relatively simple addition to a standard arthroscopic debridement procedure, but it is costly and there is no current randomised trial evidence to support its use. This trial will evaluate the clinical and cost-effectiveness of a subacromial balloon spacer for individuals undergoing arthroscopic debridement for irreparable rotator cuff tears.New surgical procedures can provide substantial benefit to patients. Good quality randomised controlled trials (RCTs) are needed, but trials in surgery are typically long and expensive, exposing patients to risk and the healthcare system to substantial costs. One way to improve the efficiency of trials is with an adaptive sample size. Such methods are well established in drug trials but have rarely, if ever, been used in surgical trials. METHODS AND ANALYSIS: Subacromial spacer for Tears Affecting Rotator cuff Tendons: a Randomised, Efficient, Adaptive Clinical Trial in Surgery (START:REACTS) is a participant and assessor blinded, adaptive, multicentre RCT comparing arthroscopic debridement with the InSpace balloon (Stryker, USA) to arthroscopic debridement alone for people with a symptomatic irreparable rotator cuff tear. It uses a group sequential adaptive design where interim analyses are performed using all of the 3, 6 and 12-month data that are available at each time point. A maximum of 221 participants will be randomised (1:1 ratio), this will provide 90% power (at the 5% level) for a 6 point difference in the primary outcome; the Oxford Shoulder Score at 12 months. A substudy will use deltoid-active MRI scans in 56 participants to assess the function of the balloon. Analysis will be on an intention-to-treat basis and reported according to principles established in the Consolidated Standards of Reporting Trials statement. ETHICS AND DISSEMINATION: NRES number 18/WM/0025. The results will be disseminated via peer-reviewed publications, presentations at conferences, lay summaries and social media. TRIAL REGISTRATION NUMBER: ISRCTN17825590.

Exercise or manual physiotherapy compared with a single session of physiotherapy for osteoporotic vertebral fracture: three-arm PROVE RCT.

BACKGROUND: A total of 25,000 people in the UK have osteoporotic vertebral fracture (OVF). Evidence suggests that physiotherapy may have an important treatment role. OBJECTIVE: The objective was to investigate the clinical effectiveness and cost-effectiveness of two different physiotherapy programmes for people with OVF compared with a single physiotherapy session. DESIGN: This was a prospective, adaptive, multicentre, assessor-blinded randomised controlled trial (RCT) with nested qualitative and health economic studies. SETTING: This trial was based in 21 NHS physiotherapy departments. PARTICIPANTS: The participants were people with symptomatic OVF. INTERVENTIONS: Seven sessions of either manual outpatient physiotherapy or exercise outpatient physiotherapy compared with the best practice of a 1-hour single session of physiotherapy (SSPT). MAIN OUTCOME MEASURES: Outcomes were measured at 4 and 12 months. The primary outcomes were quality of life and muscle endurance, which were measured by the disease-specific QUALEFFO-41 (Quality of Life Questionnaire of the European Foundation for Osteoporosis - 41 items) and timed loaded standing (TLS) test, respectively. Secondary outcomes were (1) thoracic kyphosis angle, (2) balance, evaluated via the functional reach test (FRT), and (3) physical function, assessed via the Short Physical Performance Battery (SPPB), 6-minute walk test (6MWT), Physical Activity Scale for the Elderly, a health resource use and falls diary, and the EuroQol-5 Dimensions, five-level version. RESULTS: A total of 615 participants were enrolled, with 216, 203 and 196 randomised by a computer-generated program to exercise therapy, manual therapy and a SSPT, respectively. Baseline data were available for 613 participants, 531 (86.6%) of whom were women; the mean age of these participants was 72.14 years (standard deviation 9.09 years). Primary outcome data were obtained for 69% of participants (429/615) at 12 months: 175 in the exercise therapy arm, 181 in the manual therapy arm and 173 in the SSPT arm. Interim analysis met the criteria for all arms to remain in the study. For the primary outcomes at 12 months, there were no significant benefits over SSPT of exercise [QUALEFFO-41, difference -0.23 points, 95% confidence interval (CI) -3.20 to 1.59 points; p = 1.000; and TLS test, difference 5.77 seconds, 95% CI -4.85 to 20.46 seconds; p = 0.437] or of manual therapy (QUALEFFO-41, difference 1.35 points, 95% CI -1.76 to 2.93 points; p = 0.744; TLS test, difference 9.69 seconds (95% CI 0.09 to 24.86 seconds; p = 0.335). At 4 months, there were significant gains for both manual therapy and exercise therapy over SSPT in the TLS test in participants aged < 70 years. Exercise therapy was superior to a SSPT at 4 months in the SPPB, FRT and 6MWT and manual therapy was superior to a SSPT at 4 months in the TLS test and FRT. Neither manual therapy nor exercise therapy was cost-effective relative to a SSPT using the threshold of £20,000 per quality-adjusted life-year. There were no treatment-related serious adverse events. CONCLUSIONS: This is the largest RCT to date assessing physiotherapy in participants with OVFs. At 1 year, neither treatment intervention conferred more benefit than a single 1-hour physiotherapy advice session. The focus of future work should be on the intensity and duration of interventions to determine if changes to these would demonstrate more sustained effects. TRIAL REGISTRATION: Current Controlled Trials ISRCTN49117867. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 44. See the NIHR Journals Library website for further project information.

Osteoporosis is a condition in which bones lose their strength and are more likely to break. It affects around 3 million people in the UK. Fractures of the spine are very common in people with osteoporosis. They can cause a change in body shape, back pain and difficulty with carrying out daily tasks. A treatment that may help people is physiotherapy. There is evidence that several different types of physiotherapy, such as exercise or manual (hands-on) therapy, may help. This was the largest trial of physiotherapy for people with osteoporotic vertebral fracture to date. Seven sessions of physiotherapy treatment based on either exercise or manual therapy were compared with a single 1-hour session of individualised advice from a physiotherapist. The outcome of these treatments was assessed using recognised measures of quality of life, back muscle strength, pain, function and activity at 4 months and 1 year after treatment. How safe the treatments were and whether or not they had any impact on falls or the costs of health and social care were also examined. Interviews were conducted with some of the participants in the trial to seek their opinion about the treatment that they had received. The results show that the participants tolerated all the treatments well, with no significant safety issues, and perceived treatment to be beneficial. The study did not find significant differences between the three treatments in terms of clinical effectiveness or cost-effectiveness at 1 year, although there were benefits in some areas at 4 months.

To add or not to add a new treatment arm to a multiarm study: A decision-theoretic framework.

Multiarm clinical trials, which compare several experimental treatments against control, are frequently recommended due to their efficiency gain. In practise, all potential treatments may not be ready to be tested in a phase II/III trial at the same time. It has become appealing to allow new treatment arms to be added into on-going clinical trials using a "platform" trial approach. To the best of our knowledge, many aspects of when to add arms to an existing trial have not been explored in the literature. Most works on adding arm(s) assume that a new arm is opened whenever a new treatment becomes available. This strategy may prolong the overall duration of a study or cause reduction in marginal power for each hypothesis if the adaptation is not well accommodated. Within a two-stage trial setting, we propose a decision-theoretic framework to investigate when to add or not to add a new treatment arm based on the observed stage one treatment responses. To account for different prospect of multiarm studies, we define utility in two different ways; one for a trial that aims to maximise the number of rejected hypotheses; the other for a trial that would declare a success when at least one hypothesis is rejected from the study. Our framework shows that it is not always optimal to add a new treatment arm to an existing trial. We illustrate a case study by considering a completed trial on knee osteoarthritis.

HIV self-testing alone or with additional interventions, including financial incentives, and linkage to care or prevention among male partners of antenatal care clinic attendees in Malawi: An adaptive multi-arm, multi-stage cluster randomised trial.

BACKGROUND: Conventional HIV testing services have been less comprehensive in reaching men than in reaching women globally, but HIV self-testing (HIVST) appears to be an acceptable alternative. Measurement of linkage to post-test services following HIVST remains the biggest challenge, yet is the biggest driver of cost-effectiveness. We investigated the impact of HIVST alone or with additional interventions on the uptake of testing and linkage to care or prevention among male partners of antenatal care clinic attendees in a novel adaptive trial. METHODS AND FINDINGS: An adaptive multi-arm, 2-stage cluster randomised trial was conducted between 8 August 2016 and 30 June 2017, with antenatal care clinic (ANC) days (i.e., clusters of women attending on a single day) as the unit of randomisation. Recruitment was from Ndirande, Bangwe, and Zingwangwa primary health clinics in urban Blantyre, Malawi. Women attending an ANC for the first time for their current pregnancy (regardless of trimester), 18 years and older, with a primary male partner not known to be on ART were enrolled in the trial after giving consent. Randomisation was to either the standard of care (SOC; with a clinic invitation letter to the male partner) or 1 of 5 intervention arms: the first arm provided women with 2 HIVST kits for their partners; the second and third arms provided 2 HIVST kits along with a conditional fixed financial incentive of $3 or $10; the fourth arm provided 2 HIVST kits and a 10% chance of receiving $30 in a lottery; and the fifth arm provided 2 HIVST kits and a phone call reminder for the women's partners. The primary outcome was the proportion of male partners who were reported to have tested for HIV and linked into care or prevention within 28 days, with referral for antiretroviral therapy (ART) or circumcision accordingly. Women were interviewed at 28 days about partner testing and adverse events. Cluster-level summaries compared each intervention versus SOC using eligible women as the denominator (intention-to-treat). Risk ratios were adjusted for male partner testing history and recruitment clinic. A total of 2,349/3,137 (74.9%) women participated (71 ANC days), with a mean age of 24.8 years (SD: 5.4). The majority (2,201/2,233; 98.6%) of women were married, 254/2,107 (12.3%) were unable to read and write, and 1,505/2,247 (67.0%) were not employed. The mean age for male partners was 29.6 years (SD: 7.5), only 88/2,200 (4.0%) were unemployed, and 966/2,210 (43.7%) had never tested for HIV before. Women in the SOC arm reported that 17.4% (71/408) of their partners tested for HIV, whereas a much higher proportion of partners were reported to have tested for HIV in all intervention arms (87.0%-95.4%, p < 0.001 in all 5 intervention arms). As compared with those who tested in the SOC arm (geometric mean 13.0%), higher proportions of partners met the primary endpoint in the HIVST + $3 (geometric mean 40.9%, adjusted risk ratio [aRR] 3.01 [95% CI 1.63-5.57], p < 0.001), HIVST + $10 (51.7%, aRR 3.72 [95% CI 1.85-7.48], p < 0.001), and phone reminder (22.3%, aRR 1.58 [95% CI 1.07-2.33], p = 0.021) arms. In contrast, there was no significant increase in partners meeting the primary endpoint in the HIVST alone (geometric mean 17.5%, aRR 1.45 [95% CI 0.99-2.13], p = 0.130) or lottery (18.6%, aRR 1.43 [95% CI 0.96-2.13], p = 0.211) arms. The lottery arm was dropped at interim analysis. Overall, 46 male partners were confirmed to be HIV positive, 42 (91.3%) of whom initiated ART within 28 days; 222 tested HIV negative and were not already circumcised, of whom 135 (60.8%) were circumcised as part of the trial. No serious adverse events were reported. Costs per male partner who attended the clinic with a confirmed HIV test result were $23.73 and $28.08 for the HIVST + $3 and HIVST + $10 arms, respectively. Notable limitations of the trial included the relatively small number of clusters randomised to each arm, proxy reporting of the male partner testing outcome, and being unable to evaluate retention in care. CONCLUSIONS: In this study, the odds of men's linkage to care or prevention increased substantially using conditional fixed financial incentives plus partner-delivered HIVST; combinations were potentially affordable. TRIAL REGISTRATION: ISRCTN 18421340.

Value of information methods to design a clinical trial in a small population to optimise a health economic utility function.

BACKGROUND: Most confirmatory randomised controlled clinical trials (RCTs) are designed with specified power, usually 80% or 90%, for a hypothesis test conducted at a given significance level, usually 2.5% for a one-sided test. Approval of the experimental treatment by regulatory agencies is then based on the result of such a significance test with other information to balance the risk of adverse events against the benefit of the treatment to future patients. In the setting of a rare disease, recruiting sufficient patients to achieve conventional error rates for clinically reasonable effect sizes may be infeasible, suggesting that the decision-making process should reflect the size of the target population. METHODS: We considered the use of a decision-theoretic value of information (VOI) method to obtain the optimal sample size and significance level for confirmatory RCTs in a range of settings. We assume the decision maker represents society. For simplicity we assume the primary endpoint to be normally distributed with unknown mean following some normal prior distribution representing information on the anticipated effectiveness of the therapy available before the trial. The method is illustrated by an application in an RCT in haemophilia A. We explicitly specify the utility in terms of improvement in primary outcome and compare this with the costs of treating patients, both financial and in terms of potential harm, during the trial and in the future. RESULTS: The optimal sample size for the clinical trial decreases as the size of the population decreases. For non-zero cost of treating future patients, either monetary or in terms of potential harmful effects, stronger evidence is required for approval as the population size increases, though this is not the case if the costs of treating future patients are ignored. CONCLUSIONS: Decision-theoretic VOI methods offer a flexible approach with both type I error rate and power (or equivalently trial sample size) depending on the size of the future population for whom the treatment under investigation is intended. This might be particularly suitable for small populations when there is considerable information about the patient population.

An evaluation of the fixed concentration procedure for assessment of acute inhalation toxicity.

Acute inhalation studies are conducted in animals as part of chemical hazard identification and for classification and labelling. Current methods employ death as an endpoint (Organisation for Economic Co-operation and Development (OECD) test guideline (TG) 403 and TG436) while the recently approved fixed concentration procedure (FCP) (OECD TG433) uses fewer animals and replaces lethality as an endpoint with evident toxicity. Evident toxicity is the presence of clinical signs that predict that exposure to the next highest concentration will cause severe toxicity or death in most animals. Approval of TG433 was the result of an international initiative, led by the National Centre for the Replacement, Refinement & Reduction of Animals in Research (NC3Rs), which collected data from six laboratories on clinical signs recorded for inhalation studies on 172 substances. This paper summarises previously published data and describes the additional analyses of the dataset that were essential for approval of the TG.

Investigating interventions to increase uptake of HIV testing and linkage into care or prevention for male partners of pregnant women in antenatal clinics in Blantyre, Malawi: study protocol for a cluster randomised trial.

BACKGROUND: Despite large-scale efforts to diagnose people living with HIV, 54% remain undiagnosed in sub-Saharan Africa. The gap in knowledge of HIV status and uptake of follow-on services remains wide with much lower rates of HIV testing among men compared to women. Here, we design a study to investigate the effect on uptake of HIV testing and linkage into care or prevention of partner-delivered HIV self-testing alone or with an additional intervention among male partners of pregnant women. METHODS: A phase II, adaptive, multi-arm, multi-stage cluster randomised trial, randomising antenatal clinic (ANC) days to six different trial arms. Pregnant women accessing ANC in urban Malawi for the first time will be recruited into either the standard of care (SOC) arm (invitation letter to the male partner offering HIV testing) or one of five intervention arms offering oral HIV self-test kits. Three of the five intervention arms will additionally offer the male partner a financial incentive (fixed or lottery amount) conditional on linkage after self-testing with one arm testing phone call reminders. Assuming that 25% of male partners link to care or prevention in the SOC arm, six clinic days, with a harmonic mean of 21 eligible participants, per arm will provide 80% power to detect a 0.15 absolute difference in the primary outcome. Cluster proportions will be analysed by a cluster summaries approach with adjustment for clustering and multiplicity. DISCUSSION: This trial applies adaptive methods which are novel and efficient designs. The methodology and lessons learned here will be important as proof of concept of how to design and conduct similar studies in the future. Although small, this trial will potentially present good evidence on the type of effective interventions for improving linkage into ART or prevention. The trial results will also have important policy implications on how to implement HIVST targeting male partners of pregnant women who are accessing ANC for the first time while paying particular attention to safety concerns. Contamination may occur if women in the intervention arms share their self-test kits with women in the SOC arm. TRIAL REGISTRATION: ISRCTN, ID: 18421340 . Registered on 31 March 2016.

Facet joint injections for people with persistent non-specific low back pain (Facet Injection Study): a feasibility study for a randomised controlled trial.

BACKGROUND: The National Institute for Health and Care Excellence (NICE) 2009 guidelines for persistent low back pain (LBP) do not recommend the injection of therapeutic substances into the back as a treatment for LBP because of the absence of evidence for their effectiveness. This feasibility study aimed to provide a stable platform that could be used to evaluate a randomised controlled trial (RCT) on the clinical effectiveness and cost-effectiveness of intra-articular facet joint injections (FJIs) when added to normal care. OBJECTIVES: To explore the feasibility of running a RCT to test the hypothesis that, for people with suspected facet joint back pain, adding the option of intra-articular FJIs (local anaesthetic and corticosteroids) to best usual non-invasive care is clinically effective and cost-effective. DESIGN: The trial was a mixed design. The RCT pilot protocol development involved literature reviews and a consensus conference followed by a randomised pilot study with an embedded mixed-methods process evaluation. SETTING: Five NHS acute trusts in England. PARTICIPANTS: Participants were patients aged ≥ 18 years with moderately troublesome LBP present (> 6 months), who had failed previous conservative treatment and who had suspected facet joint pain. The study aimed to recruit 150 participants (approximately 30 per site). Participants were randomised sequentially by a remote service to FJIs combined with 'best usual care' (BUC) or BUC alone. INTERVENTIONS: All participants were to receive six sessions of a bespoke BUC rehabilitation package. Those randomised into the intervention arm were, in addition, given FJIs with local anaesthetic and steroids (at up to six injection sites). Randomisation occurred at the end of the first BUC session. MAIN OUTCOME MEASURES: Process and clinical outcomes. Clinical outcomes included a measurement of level of pain on a scale from 0 to 10, which was collected daily and then weekly via text messaging (or through a written diary). Questionnaire follow-up was at 3 months. RESULTS: Fifty-two stakeholders attended the consensus meeting. Agreement informed several statistical questions and three design considerations: diagnosis, the process of FJI and the BUC package and informing the design for the randomised pilot study. Recruitment started on 26 June 2015 and was terminated by the funder (as a result of poor recruitment) on 11 December 2015. In total, 26 participants were randomised. Process data illuminate some of the reasons for recruitment problems but also show that trial processes after enrolment ran smoothly. No between-group analysis was carried out. All pain-related outcomes show the expected improvement between baseline and follow-up. The mean total cost of the overall treatment package (injection £419.22 and BUC £264.00) was estimated at £683.22 per participant. This is similar to a NHS tariff cost for a course of FJIs of £686.84. LIMITATIONS: Poor recruitment was a limiting factor. CONCLUSIONS: This feasibility study achieved consensus on the main challenges in a trial of FJIs for people with persistent non-specific low back pain. FUTURE WORK: Further work is needed to test recruitment from alternative clinical situations. TRIAL REGISTRATION: EudraCT 2014-000682-50 and Current Controlled Trials ISRCTN93184143. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 30. See the NIHR Journals Library website for further project information.

Randomised controlled trial evaluating the effectiveness and cost-effectiveness of 'Families for Health', a family-based childhood obesity treatment intervention delivered in a community setting for ages 6 to 11 years.

BACKGROUND: Effective programmes to help children manage their weight are required. 'Families for Health' focuses on a parenting approach, designed to help parents develop their parenting skills to support lifestyle change within the family. Families for Health version 1 showed sustained reductions in mean body mass index (BMI) z-score after 2 years in a pilot project. OBJECTIVE: The aim was to evaluate its effectiveness and cost-effectiveness in a randomised controlled trial (RCT). DESIGN: The trial was a multicentre, investigator-blind RCT, with a parallel economic and process evaluation, with follow-up at 3 and 12 months. Randomisation was by family unit, using a 1 : 1 allocation by telephone registration, stratified by three sites, with a target of 120 families. SETTING: Three sites in the West Midlands, England, UK. PARTICIPANTS: Children aged 6-11 years who were overweight (≥ 91st centile BMI) or obese (≥ 98th centile BMI), and their parents/carers. Recruitment was via referral or self-referral. INTERVENTIONS: Families for Health version 2 is a 10-week, family-based community programme with parallel groups for parents and children, addressing parenting, lifestyle, social and emotional development. Usual care was the treatment for childhood obesity provided within each locality. MAIN OUTCOME MEASURES: Joint primary outcome measures were change in children's BMI z-score and incremental cost per quality-adjusted life-year (QALY) gained at 12 months' follow-up (QALYs were calculated using the European Quality of Life-5 Dimensions Youth version). Secondary outcome measures included changes in children's waist circumference, percentage body fat, physical activity, fruit/vegetable consumption and quality of life. Parents' BMI and mental well-being, family eating/activity, parent-child relationships and parenting style were also assessed. The process evaluation documented recruitment, reach, dose delivered, dose received and fidelity, using mixed methods. RESULTS: The study recruited 115 families (128 children; 63 boys and 65 girls), with 56 families randomised to the Families for Health arm and 59 to the 'usual-care' control arm. There was 80% retention of families at 3 months (Families for Health, 46 families; usual care, 46 families) and 72% retention at 12 months (Families for Health, 44 families; usual care, 39 families). The change in BMI z-score at 12 months was not significantly different in the Families for Health arm and the usual-care arm [0.114, 95% confidence interval (CI) -0.001 to 0.229; p = 0.053]. However, within-group analysis showed that the BMI z-score was significantly reduced in the usual-care arm (-0.118, 95% CI -0.203 to -0.034; p = 0.007), but not in the Families for Health arm (-0.005, 95% CI -0.085 to 0.078; p = 0.907). There was only one significant difference between groups for secondary outcomes. The economic evaluation, taking a NHS and Personal Social Services perspective, showed that mean costs 12 months post randomisation were significantly higher for Families for Health than for usual care (£998 vs. £548; p < 0.001). The mean incremental cost-effectiveness of Families for Health was estimated at £552,175 per QALY gained. The probability that the Families for Health programme is cost-effective did not exceed 40% across a range of thresholds. The process evaluation demonstrated that the programme was implemented, as planned, to the intended population and any adjustments did not deviate widely from the handbook. Many families waited more than 3 months to receive the intervention. Facilitators', parents' and children's experiences of Families for Health were largely positive and there were no adverse events. Further analysis could explore why some children show a clinically significant benefit while others have a worse outcome. CONCLUSIONS: Families for Health was neither effective nor cost-effective for the management of obesity in children aged 6-11 years, in comparison with usual care. Further exploration of the wide range of responses in BMI z-score in children following the Families for Health and usual-care interventions is warranted, focusing on children who had a clinically significant benefit and those who showed a worse outcome with treatment. Further research could focus on the role of parents in the prevention of obesity, rather than treatment. TRIAL REGISTRATION: Current Controlled Trials ISRCTN45032201. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 1. See the NIHR Journals Library website for further project information.

Randomised controlled trial and economic evaluation of the 'Families for Health' programme to reduce obesity in children.

OBJECTIVE: Evaluating effectiveness and cost-effectiveness of 'Families for Health V2' (FFH) compared with usual care (UC). DESIGN: Multicentre randomised controlled trial (RCT) (investigators blinded, families unblinded) and economic evaluation. Stratified randomisation by family; target of 120 families. SETTING: Three National Health Service Primary Care Trusts in West Midlands, England. PARTICIPANTS: Overweight or obese (≥91st or ≥98th centile body mass index (BMI)) children aged 6-11 years and their parents/carers, recruited March 2012-February 2014. INTERVENTIONS: FFH; a 10-week community-based family programme addressing parenting, lifestyle change and social and emotional development. UC; usual support for childhood obesity at each site. MAIN OUTCOME MEASURES: Primary outcomes were 12-months change in children's BMI z-score and incremental cost per quality-adjusted life-year gained (QALY). Secondary outcomes included changes in children's physical activity, fruit and vegetable consumption and quality of life, parents' BMI and mental well-being, family eating/activity, parent-child relationships and parenting style. RESULTS: 115 families (128 children) were randomised to FFH (n=56) or UC (n=59). There was no significant difference in BMI z-score 12-months change (0.114, 95% CI -0.001 to 0.229, p=0.053; p=0.026 in favour of UC with missing value multiple imputation). One secondary outcome, change in children's waist z-score, was significantly different between groups in favour of UC (0.15, 95% CI 0.00 to 0.29). Economic evaluation showed that mean costs were significantly higher for FFH than UC (£998 vs £548, p<0.001). Mean incremental cost-effectiveness of FFH was estimated at £552 175 per QALY. CONCLUSIONS: FFH was neither effective nor cost-effective for the management of obesity compared with UC. TRIAL REGISTRATION NUMBER: ISRCTN45032201.

Pre-hospital Assessment of the Role of Adrenaline: Measuring the Effectiveness of Drug administration In Cardiac arrest (PARAMEDIC-2): Trial protocol.

Despite its use since the 1960s, the safety or effectiveness of adrenaline as a treatment for cardiac arrest has never been comprehensively evaluated in a clinical trial. Although most studies have found that adrenaline increases the chance of return of spontaneous circulation for short periods, many studies found harmful effects on the brain and raise concern that adrenaline may reduce overall survival and/or good neurological outcome. The PARAMEDIC-2 trial seeks to determine if adrenaline is safe and effective in out-of-hospital cardiac arrest. This is a pragmatic, individually randomised, double blind, controlled trial with a parallel economic evaluation. Participants will be eligible if they are in cardiac arrest in the out-of-hospital environment and advanced life support is initiated. Exclusions are cardiac arrest as a result of anaphylaxis or life threatening asthma, and patient known or appearing to be under 16 or pregnant. 8000 participants treated by 5 UK ambulance services will be randomised between December 2014 and August 2017 to adrenaline (intervention) or placebo (control) through opening pre-randomised drug packs. Clinical outcomes are survival to 30 days (primary outcome), hospital discharge, 3, 6 and 12 months, health related quality of life, and neurological and cognitive outcomes (secondary outcomes). Trial registration (ISRCTN73485024).

OPTIMA prelim: a randomised feasibility study of personalised care in the treatment of women with early breast cancer.

BACKGROUND: There is uncertainty about the chemotherapy sensitivity of some oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers. Multiparameter assays that measure the expression of several tumour genes simultaneously have been developed to guide the use of adjuvant chemotherapy for this breast cancer subtype. The assays provide prognostic information and have been claimed to predict chemotherapy sensitivity. There is a dearth of prospective validation studies. The Optimal Personalised Treatment of early breast cancer usIng Multiparameter Analysis preliminary study (OPTIMA prelim) is the feasibility phase of a randomised controlled trial (RCT) designed to validate the use of multiparameter assay directed chemotherapy decisions in the NHS. OBJECTIVES: OPTIMA prelim was designed to establish the acceptability to patients and clinicians of randomisation to test-driven treatment assignment compared with usual care and to select an assay for study in the main RCT. DESIGN: Partially blinded RCT with adaptive design. SETTING: Thirty-five UK hospitals. PARTICIPANTS: Patients aged ≥ 40 years with surgically treated ER-positive HER2-negative primary breast cancer and with 1-9 involved axillary nodes, or, if node negative, a tumour at least 30 mm in diameter. INTERVENTIONS: Randomisation between two treatment options. Option 1 was standard care consisting of chemotherapy followed by endocrine therapy. In option 2, an Oncotype DX(®) test (Genomic Health Inc., Redwood City, CA, USA) performed on the resected tumour was used to assign patients either to standard care [if 'recurrence score' (RS) was > 25] or to endocrine therapy alone (if RS was ≤ 25). Patients allocated chemotherapy were blind to their randomisation. MAIN OUTCOME MEASURES: The pre-specified success criteria were recruitment of 300 patients in no longer than 2 years and, for the final 150 patients, (1) an acceptance rate of at least 40%; (2) recruitment taking no longer than 6 months; and (3) chemotherapy starting within 6 weeks of consent in at least 85% of patients. RESULTS: Between September 2012 and 3 June 2014, 350 patients consented to join OPTIMA prelim and 313 were randomised; the final 150 patients were recruited in 6 months, of whom 92% assigned chemotherapy started treatment within 6 weeks. The acceptance rate for the 750 patients invited to participate was 47%. Twelve out of the 325 patients with data (3.7%, 95% confidence interval 1.7% to 5.8%) were deemed ineligible on central review of receptor status. Interviews with researchers and recordings of potential participant consultations made as part of the integral qualitative recruitment study provided insights into recruitment barriers and led to interventions designed to improve recruitment. Patient information was changed as the result of feedback from three patient focus groups. Additional multiparameter analysis was performed on 302 tumour samples. Although Oncotype DX, MammaPrint(®)/BluePrint(®) (Agendia Inc., Irvine, CA, USA), Prosigna(®) (NanoString Technologies Inc., Seattle, WA, USA), IHC4, IHC4 automated quantitative immunofluorescence (AQUA(®)) [NexCourse BreastTM (Genoptix Inc. Carlsbad, CA, USA)] and MammaTyper(®) (BioNTech Diagnostics GmbH, Mainz, Germany) categorised comparable numbers of tumours into low- or high-risk groups and/or equivalent molecular subtypes, there was only moderate agreement between tests at an individual tumour level (kappa ranges 0.33-0.60 and 0.39-0.55 for tests providing risks and subtypes, respectively). Health economics modelling showed the value of information to the NHS from further research into multiparameter testing is high irrespective of the test evaluated. Prosigna is currently the highest priority for further study. CONCLUSIONS: OPTIMA prelim has achieved its aims of demonstrating that a large UK clinical trial of multiparameter assay-based selection of chemotherapy in hormone-sensitive early breast cancer is feasible. The economic analysis shows that a trial would be economically worthwhile for the NHS. Based on the outcome of the OPTIMA prelim, a large-scale RCT to evaluate the clinical effectiveness and cost-effectiveness of multiparameter assay-directed chemotherapy decisions in hormone-sensitive HER2-negative early breast would be appropriate to take place in the NHS. TRIAL REGISTRATION: Current Controlled Trials ISRCTN42400492. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 10. See the NIHR Journals Library website for further project information. The Government of Ontario funded research at the Ontario Institute for Cancer Research. Robert C Stein received additional support from the NIHR University College London Hospitals Biomedical Research Centre.

Decision-theoretic designs for small trials and pilot studies: A review.

Pilot studies and other small clinical trials are often conducted but serve a variety of purposes and there is little consensus on their design. One paradigm that has been suggested for the design of such studies is Bayesian decision theory. In this article, we review the literature with the aim of summarizing current methodological developments in this area. We find that decision-theoretic methods have been applied to the design of small clinical trials in a number of areas. We divide our discussion of published methods into those for trials conducted in a single stage, those for multi-stage trials in which decisions are made through the course of the trial at a number of interim analyses, and those that attempt to design a series of clinical trials or a drug development programme. In all three cases, a number of methods have been proposed, depending on the decision maker's perspective being considered and the details of utility functions that are used to construct the optimal design.

Can we convert between outcome measures of disability for chronic low back pain?

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: A range of patient-reported outcomes were used to measure disability due to low back pain. There is not a single back pain disability measurement commonly used in all randomized controlled trials. We report here our assessment as to whether different disability measures are sufficiently comparable to allow data pooling across trials. SUMMARY OF BACKGROUND DATA: We used individual patient data from a repository of data from back pain trials of therapist-delivered interventions. METHODS: We used data from 11 trials (n=6089 patients) that had at least 2 of the following 7 measurements: Roland-Morris Disability Questionnaire, Chronic Pain Grade disability score, Physical Component Summary of the 12- or 36-Item Short Form Health Survey, Patient Specific Functional Scale, Pain Disability Index, Oswestry Disability Index, and Hannover Functional Ability Questionnaire. Within each trial, the change score between baseline and short-term follow-up was computed for each outcome and this was used to calculate the correlation between the change scores and the Cohen's κ for the 3-level outcome of change score of less than, equal to, and more than zero. It was considered feasible to pool 2 measures if they were at least moderately correlated (correlation>0.5) and have at least moderately similar responsiveness (κ>0.4). RESULTS: Although all pairs of measures were found to be positively correlated, most correlations were less than 0.5, with only 1 pair of outcomes in 1 trial having a correlation of more than 0.6. All κ statistics were less than 0.4 so that in no cases were the criteria for acceptability of pooling measures satisfied. CONCLUSION: The lack of agreement between different outcome measures means that pooling of data on these different disability measurements in a meta-analysis is not recommended. LEVEL OF EVIDENCE: 2.