Selective outcome reporting in paediatric dentistry restorative treatment randomised clinical trials-A meta-research.

Background: Selective outcome reporting (SOR) is a bias that occurs when the primary outcome of a randomised clinical trial (RCT) is omitted or changed.

Aim: To evaluate the prevalence of SOR in RCTs on restorative treatment in primary teeth.

Design: We conducted an electronic search on ClinicalTrials.gov and the World Health Organization platform (International Clinical Trials Registry Platform) on 1 of April 2021, with no registry time or language restrictions. We included RCT protocols that evaluated restorative treatments in primary teeth and excluded trials that did not have a complete publication in a scientific journal. The chi-squared test was used to identify the association between SOR and variables as a discrepancy in the follow-up period, the timing of registration, the type of sponsorship and the type of study design (α = 5%).

Results: Of the 294 identified protocols, 30 were included in the study. 83.3% of trials were registered retrospectively. SOR was observed in 53.3% (n = 16) of the published trials and was significantly associated with a discrepancy in the follow-up period (p = .017).

Conclusions: The high prevalence of SOR in RCTs on restorative treatment proves that this is a prominent threat. A proper preregistered protocol, declaration of any protocol deviation and allowance of stakeholders to compare the protocol with that of the submitted papers will achieve transparency.