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Objective: To undertake meta-analysis and compare treatment effects estimated by the intention-to-treat (ITT) method and per-protocol (PP) method in randomized controlled trials (RCTs). PP excludes trial participants who are non-adherent to trial protocol in terms of eligibility, interventions, or outcome assessment., Study Design and Setting: Five high impact journals were searched for all RCTs published between July 2017 to June 2019. Primary outcome was a pooled estimate that quantified the difference between the treatment effects estimated by the two methods. Results are presented as ratio of odds ratios (ROR). Meta-regression was used to explore the association between level of trial protocol non-adherence and treatment effect. Sensitivity analyses compared results with varying within-study correlations and across various study characteristics., Results: Random-effects meta-analysis (N = 156) showed that PP estimates were on average 2% greater compared to the ITT estimates (ROR: 1.02, 95% CI: 1.00-1.04, P = 0.03). The divergence further increased with higher degree of protocol non-adherence. Sensitivity analyses reassured consistent results with various within-study correlations and across various study characteristics., Conclusion: There was evidence of larger treatment effect with PP compared to ITT analysis. PP analysis should not be used to assess the impact of protocol non-adherence in RCTs. Instead, in addition to ITT, investigators should consider randomization based casual method such as Complier Average Causal Effect (CACE)., (Copyright © 2021. Published by Elsevier Inc.)

A clinical hold order by the Food and Drug Administration (FDA) to the sponsor of a clinical trial is a measure to delay a proposed or to suspend an ongoing clinical investigation. The phase III clinical trial START serves as motivating data example to explore implications and potential statistical approaches for a trial continuing after a clinical hold is lifted. In spite of a modified intention-to-treat (ITT) analysis introduced to account for the clinical hold by excluding patients potentially affected most by the clinical hold, results of the trial did not show a significant improvement of overall survival duration, and the question remains whether the negative result was an effect of the clinical hold. In this paper, we propose a multistate model incorporating the clinical hold as well as disease progression as intermediate events to investigate the impact of the clinical hold on the treatment effect. Moreover, we consider a simple counterfactual censoring approach as alternative strategy to the modified ITT analysis to deal with a clinical hold. Using a realistic simulation study informed by the START data and with a design based on our multistate model, we show that the modified ITT analysis used in the START trial was reasonable. However, the censoring approach will be shown to have some benefits in terms of power and flexibility., (© 2019 The Authors. Pharmaceutical Statistics published by John Wiley & Sons Ltd.)

Background: Industry funders can simply provide money or collaborate in trial design, analysis or reporting of clinical trials. Our aim was to assess the impact of industry collaboration on trial methodology and results of randomised controlled trials (RCT)., Methods: We searched PubMed for oncology RCTs published May 2013 to December 2015 in peer-reviewed journals with impact factor > 5 requiring reporting of funder role. Two authors extracted methodologic (primary end-point; blinding of the patient, clinician and outcomes assessor; and analysis) and outcome data. We used descriptive statistics and two-sided Fisher exact tests to compare characteristics of trials with collaboration, with industry funding only, and without industry funding., Results: We included 224 trials. Compared to those without industry funding, trials with collaboration used more placebo control (RR 3·59, 95% CI [1·88-6·83], p < 0001), intention-to-treat analysis (RR 1·32, 95% CI [1·04-1·67], p = 02), and blinding of patients (RR 3·05, 95% CI [1·71-5·44], p < 0001), clinicians (RR 3·36, 95% CI [1·83-6·16], p≤·001) and outcomes assessors (RR 3·03, 95% CI [1·57-5·83], p = 0002). They did not differ in use of overall survival as a primary end-point (RR 1·27 95% CI [0·72-2·24]) and were similarly likely to report positive results (RR 1·11 95% CI [0·85-1·46], p = 0.45). Studies with funding only did not differ from those without funding., Conclusions: Oncology RCTs with industry collaboration were more likely to use some high-quality methods than those without industry funding, with similar rates of positive results. Our findings suggest that collaboration is not associated with trial outcomes and that mandatory disclosure of funder roles may mitigate bias., Competing Interests: statement None declared., (Copyright © 2016 Elsevier Ltd. All rights reserved.)