Reporting of CONSORT flow diagrams for parallel group randomized controlled trials published in orthodontic journals.

Background/objectives: The inclusion of a participant flow diagram in randomized clinical trials (RCTs) is a requirement of the CONSORT guidelines. The aim of this study was to assess the reporting quality of flow diagrams of RCTs published in orthodontic journals in relation to the CONSORT Flow Diagram for Parallel Group RCTs.

Materials/methods: RCTs published between January 2011 and December 2023 in five orthodontic journals were identified and trial characteristics were extracted. The reporting of the flow diagram (if included) was assessed for completeness in relation to the CONSORT flow diagram template. Descriptive statistics and cross tabulations between RCT characteristics and presence/no presence of a flow diagram were performed. On an exploratory basis, univariable associations between RCT characteristics and presence/no presence of a flow diagram were performed and univariable logistic regression to examine the effect of publication year on flow diagram reporting.

Results: Three hundred and thirty-four RCTs met the inclusion criteria. The majority were published in 2021 (n = 39, 11.7%), and had 2 arms (n = 279, 83.5%). Three-hundred and seven (92.0%) RCTs were published in journals endorsing the CONSORT guidelines. Two hundred and thirty-three (69.8%) RCTs included a flow diagram and from these, 48.1% (n = 112) were fully compliant with flow diagram reporting. 121 (51.9%) omitted at least one item of the CONSORT reporting template. Significant associations between journal type, CONSORT endorsement by authors, ethical approval status, presence of a published protocol, significance of the primary outcome, involvement of a statistician, presence of conflict of interest, center type, type of analysis undertaken and the presence/ no presence of a flow diagram were present. Across the study timeframe, the odds of inclusion of RCT flow diagram increased per additional year (OR:1.47; 95%CI:1.34,1.61; p < .001).

Limitations: Only five orthodontic journals.

Conclusions/implications: Despite improvements over time, the inclusion and reporting of CONSORT flow diagram for parallel group RCTs in trials published in orthodontic journals requires improvement. To mitigate potential biased interpretation of trial results, journal editors should ensure a complete CONSORT flow diagram is submitted by researchers.