The CONSORT extension for Stepped-Wedge Cluster Randomised Trials: baseline assessment of reporting quality -and assessment of inter-rater reliability using a crowd-sourcing systematic review

The Consolidated Standards Of Reporting Trials (CONSORT) extension for the stepped-wedge cluster randomised trial (SW-CRT) is a recently published reporting guideline for SW-CRTs. We assess the quality of reporting of a recent sample of SW-CRTs according to the 26 items in the new guideline using a novel crowd sourcing methodology conducted independently and in duplicate, with random assignment, by 50 reviewers. We assessed reliability of the quality assessments, proposing this as a novel way to assess robustness of items in reporting guidelines. Several items were well reported. Some items were very poorly reported, including several items that have unique requirements for the SW-CRT, such as the rationale for use of the design, description of the design, identification and recruitment of participants within clusters, and concealment of cluster allocation (not reported in more than 50% of the reports). Agreement across items was moderate (median percentage agreement was 76% [IQR 64 to 86]). Agreement was low for several items including the description of the trial design and why trial ended or stopped for example. When reporting SW-CRTs authors should pay particular attention to ensure clear reporting on the exact format of the design with justification, as well as how clusters and individuals were identified for inclusion in the study, and whether this was done before or after randomisation of the clusters, which are crucial for risk of bias assessments. Some items, including why the trial ended might either not be relevant to SW-CRTs, or might be unclearly described in the statement.This research was partly funded by the UK NIHR Collaborations for Leadership in Applied Health Research and Care West Midlands initiative. Karla Hemming is funded by a NIHR Senior Research Fellowship SRF-2017-10-002. Jennifer Thompson is funded by the Medical Research Council UK