Predictors of ethical approval and informed consent in orthodontic RCTs.

OBJECTIVES: Determine the number of orthodontic randomized controlled trials (RCTs) published in four key orthodontic journals from 1 January 2001 to 31 December 2010, whether details about ethical approval (EA) and/or informed consent (IC) were reported and identify predictors for reporting EA and IC in orthodontic RCTs.

DESIGN: Retrospective observational study.

SETTING: American Journal of Orthodontics and Dentofacial Orthopedics (AJODO), Angle Orthodontist (AO), European Journal of Orthodontics (EJO) and Journal of Orthodontics (JO) from 2001 to 2010.

INTERVENTIONS: AJODO, AO, EJO and JO were handsearched to identify all RCTs published from 1 January 2001 to 31 December 2010.

MAIN OUTCOME MEASURE: The RCTs were assessed to identify: inclusion of details about EA and IC, publication journal, number of authors, number and location of centres involved, perceived statistician involvement, publication year and inclusion of random* in either the title, abstract or body of the text.

RESULTS: 218 RCTs were published. 109 (48·6%) had reported both EA and IC, 59 (27·1%) neither and 53 (12·9%) either EA or IC. Factors associated with an RCT reporting obtaining EA and IC: number of authors (P<0·001), random* in title (P<0·001), random* in abstract but not title (P<0·001), location of origin (P = 0·001), publication year (P = 0·003), journal of publication (P = 0·004) and number of centres (P = 0·008). Logistic regression suggested the most significant indicators of reporting EA and IC were: publication in the JO (P = 0·018), >6 authors (P<0·001), random* in the abstract but not title (P = 0·004) and publication after 2004 (P = 0·001).

CONCLUSIONS: RCTs were most likely to have reported EA and IC when published in the JO, after 2004 while having more than six authors and random* in the abstract but not title.