Trial registration in Latin America and the Caribbean's: study of randomized trials published in 2010.

OBJECTIVE: To determine the prevalence of trial registration in randomized controlled trials (RCTs) published in 2010 (PUBMED/LILACS) from Latin America and the Caribbean's (LAC) and to compare methodological characteristics between registered and nonregistered RCTs.

STUDY DESIGN AND SETTING: A search for detecting RCTs in which at least the first/contact author had a LAC's affiliation was made. We determined if RCTs were registered in the International Clinical Trial Registry Platform (ICTRP). Data were independently extracted by two authors. The risk of bias (RoB) was assessed in all registered RCTs (n=89) and in a sample of nonregistered RCTs (n=237).

RESULTS: The search identified 1,695 references; 526 RCTs from 19 countries were included. 16.9% (89/526) of RCTs were registered in the ICTRP; however, only 21 (4.0%) were prospectively registered. A significant difference was found in the overall assessment of the RoB between registered and nonregistered RCTs. Overall, registered RCTs were multinational, had larger sample size and longer follow-up, and reported more frequently information on funding, conflict of interests, and ethic issues. No significant differences were found when analyzing prospectively registered RCTs.

CONCLUSION: This study shows that trial registration rates are still low in LAC and the quality of reporting needs to be improved.