Has the reporting quality of published randomised controlled trial protocols improved since the SPIRIT statement? A methodological study

ObjectivesTo determine the reporting quality of published randomised controlled trial (RCT) protocols before and after the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) statement (2013), and any association with author, trial or journal factors.DesignMethodological study.Data sourcesMEDLINE, Embase and CENTRAL were electronically searched using optimised search strategies.Eligibility criteriaProtocols written for an RCT of living humans, published in full text in a peer-reviewed journal and published in the English language.Main outcomePrimary outcome was the overall proportion of checklist items which were adequately reported in RCT protocols published before and after the SPIRIT statement.Results300 RCT protocols were retrieved; 150 from the period immediately before the SPIRIT statement (9 July 2012 to 28 December 2012) and 150 from a recent period after the SPIRIT statement (25 January 2019 to 20 March 2019). 47.9% (95% CI, 46.5% to 49.3%) of checklist items were adequately reported in RCT protocols before the SPIRIT statement and 56.7% (95% CI, 54.9% to 58.5%) after the SPIRIT statement. This represents an 8.8% (95% CI, 6.6% to 11.1%; p