We have identified that many trials fail to adequately pre-specify their statistical analysis approach. This is problematic since it allows analysts to choose the method which gives the most favourable result. To ensure methods cannot be chosen based on results we have developed a five point framework for the pre-specification of the statistical analysis strategy in clinical trials (Pre-SPEC). The five points are: (1) Pre-specify before recruitment to the trial begins; (2) Specify a single primary analysis strategy; (3) Plan all aspects of the analysis; (4) Enough detail should be provided so that a third party could independently perform the analysis; and (5) Choices in adaptive analysis strategies should use deterministic decision rules.

A pre-print of the framework, written by Suzie Cro, Brennan Kahan (QMUL) and Gordon Forbes (KCL), is available at the below link and we welcome any comments on this work in progress.

Pre-SPEC: A framework for the pre-specification of statistical analysis strategies in clinical trials