The clear reporting of study limitations in the reports of orthodontic randomized controlled trials is not routinely undertaken: A systematic search and review.

Introduction: To ensure accurate interpretation of the generalizability of trial findings, the clear reporting of limitations is imperative. This review aimed to assess whether study limitations are reported in full-text articles of orthodontic randomized controlled trials (RCTs). Associations between the trial characteristics and the reporting of limitations were also explored.

Methods: In this review, RCTs published between January 1, 2011 and December 31, 2021 were identified from 5 orthodontic journals with the highest impact factor. Trial characteristics were extracted from the individual reports. To ascertain if limitations were reported in reports of RCTs, a criterion was developed from previously published literature. Descriptive statistics and associations between the reporting of limitations and trial characteristics were explored.

Results: Three hundred and eighty-six trials were analyzed. In relation to the criterion, the clear reporting of trial limitations was deficient across several areas. Most RCTs were published in 2021 (12.7%), had authors based in Asia and other regions (42.2%), did not have a statistician involved (85.8%), and were materials and devices type trials (48.7%). An association was detected between the year of publication, impact factor, journal and journal submission instructions, and reporting of study limitations. More recent trials published in journals with higher impact factors were more likely to report limitations in the main manuscript. Journals with suggested or mandatory instructions were more likely to report limitations in the trials they publish than journals with no reference to reporting limitations in the manuscript in the journal submission instructions.

Conclusions: Authors of trials should not view the reporting of limitations as a weakness of their trial but rather as an opportunity to provide further information to allow clinicians to fully interpret the generalizability of the results. Scientific journals should stipulate and facilitate the reporting of study limitations within manuscripts.