Allocation concealment appraisal of clinical therapy trials using the extended Composite Quality Score (CQS-2): An empirically based update (Protocol)

Abstract Objectives: To revise CQS-2/Criterion II, concerning allocation concealment appraisal for prospective, controlled, clinical therapy trials. Methods: Meta-analyses of trials with inadequate allocation concealment will be tested for in-between trial heterogeneity (I2 > 0) due to imbalances in baseline variables. Meta-analyses with positive test results will be used as basis to infer criteria for adequate allocation concealment. The CQS-2/Criterion II will be reformulated in line with the findings. The revised appraisal tool will be specified as CQS-2B Reporting: The final report will be made available online as preprint in one of the major preprint repositories and submitted to a peer-reviewed journal.