Article type
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Abstract
Introduction: Adherence to clinical trial registration in Latin American and the Caribbean (LAC) countries is yet to be evaluated.
Objective: Determine the prevalence of registration of randomized controlled trials (RCT) published in PUBMED-LILACS in 2010 from LAC in the International Clinical Trial Registry Platform (ICTRP) compliant databases; and to compare methodological characteristics of registered vs. non-registered RCT.
Methods: A search for detecting RCTs in which at least the first author had a LAC’s affiliation was made. The RCT was included if it explicitly used the word 'random’ or variations thereof. Trials not including human subjects were excluded. No language restrictions were applied. We assessed the full text of the reports to determine if the RCT had been registered in a register contributing to the ICTRP. Data from studies were independently extracted by two authors. We assessed the risk of bias (RoB) in all registered RCTs (n = 89) and in a sample of non-registered RCTs (n = 237).
Results: The search identified 1695 references; we included 526RCTs from 19countries of which 16.9% (89/526) were registered in the ICTRP. Prospective registration was done in 21 (4.0%) RCTs. We found a significant difference in the overall RoB assessment between registered (5.1% high; 60.3% unclear; and 34.6% low risk) and non-registered RCTs (high 18.5% unclear 59.3% and 22.2% low risk); significant differences were also found in the proportion of 'allocation concealment’ and 'other types of bias' domains of the RoB. The number of RCTs reporting conflict of interests, approval by an ethics committee and the provision of informed consent were significantly higher in registered studies. No significant differences were found when analyzing only prospectively registered vs. non-registered RCTs.
Conclusion: There is a significant association between clinical trial registration with lower RoB and with a better quality assessment. There is room for improvement in trial registration adherence.
Objective: Determine the prevalence of registration of randomized controlled trials (RCT) published in PUBMED-LILACS in 2010 from LAC in the International Clinical Trial Registry Platform (ICTRP) compliant databases; and to compare methodological characteristics of registered vs. non-registered RCT.
Methods: A search for detecting RCTs in which at least the first author had a LAC’s affiliation was made. The RCT was included if it explicitly used the word 'random’ or variations thereof. Trials not including human subjects were excluded. No language restrictions were applied. We assessed the full text of the reports to determine if the RCT had been registered in a register contributing to the ICTRP. Data from studies were independently extracted by two authors. We assessed the risk of bias (RoB) in all registered RCTs (n = 89) and in a sample of non-registered RCTs (n = 237).
Results: The search identified 1695 references; we included 526RCTs from 19countries of which 16.9% (89/526) were registered in the ICTRP. Prospective registration was done in 21 (4.0%) RCTs. We found a significant difference in the overall RoB assessment between registered (5.1% high; 60.3% unclear; and 34.6% low risk) and non-registered RCTs (high 18.5% unclear 59.3% and 22.2% low risk); significant differences were also found in the proportion of 'allocation concealment’ and 'other types of bias' domains of the RoB. The number of RCTs reporting conflict of interests, approval by an ethics committee and the provision of informed consent were significantly higher in registered studies. No significant differences were found when analyzing only prospectively registered vs. non-registered RCTs.
Conclusion: There is a significant association between clinical trial registration with lower RoB and with a better quality assessment. There is room for improvement in trial registration adherence.