Post-submission changes to prespecified statistical analysis plans.

Competing Interests: Competing interests: We have read and understood BMJ policy on declaration of interests and declare that all authors are involved in assessing research submitted to The BMJ for publication. JSR receives research support through Yale University from Johnson and Johnson to develop methods of clinical trial data sharing, from the Medical Device Innovation Consortium as part of the National Evaluation System for Health Technology (NEST), from the Food and Drug Administration for the Yale-Mayo Clinic CERSI program (U01FD005938), from the Agency for Healthcare Research and Quality (R01HS022882), from the National Heart, Lung and Blood Institute of the National Institutes of Health (NIH) (R01HS025164, R01HL144644), and from Arnold Ventures. He is an expert witness at the request of relator’s attorneys, the Greene Law Firm, in a qui tam suit alleging violations of the False Claims Act and Anti-Kickback Statute against Biogen. TF is funded by the National Institute of Allergy and Infectious Diseases and has received funds from unrelated consulting work for Takeda, Pfizer, Acadia and iHeed.