Citation of prior systematic reviews in reports of randomized controlled trials published in dental speciality journals.

OBJECTIVES

To assess the extent to which reports of dental Randomised Clinical Trials (RCTs) cite prior systematic reviews (SR) to explain the rationale or justification of the trial. Study characteristics that predicated the citation of SR in the RCT report were explored.

METHODS

An electronic database search was undertaken to identify dental RCTs published between 1st January 2014 and 31st December 2019. All titles and abstracts were screened independently by two authors. Descriptive statistics and associations were calculated for the study characteristics. Logistic regression was used to identify predicators of SR inclusion in the trial report.

RESULTS

682 RCTs were analysed. 312 SRs were available of which 62.5 % were cited and 37.5 % were not included but were available in the literature within 12 months of trial commencement. An association between inclusion of SR and trial registration (P = 0.046) was detected. For the inclusion of a SR, authors based in Asia or other had lower odds than those based in Europe (OR: 0.53; 95 % CI:0.34,0.82; p = 0.005). Every unit increase in journal impact factor increased the odds of SR inclusion (OR: 1.23; 95 %: 1.06, 1.43; p = 0.006).

CONCLUSIONS

A relatively high proportion of dental RCTs (37.5 %) did not cite a SR in the introduction section to justify the rationale of the trial when a relevant SR was available. Trials conducted by a corresponding author based in Europe and published in journals with an increasing impact factor were also more likely to cite a SR.

CLINICAL SIGNIFICANCE

Further progress is required to minimise research waste and ensure resources are channelled towards clinically useful trials which have an appropriate rationale and justification.