Impact of the trial registration initiative in Latin America and the Caribbean: a study of randomized controlled trials published in 2010

Poster
2011 Madrid
Reveiz L1, Bonfill X2, Glujovsky D3, Pinzon C4, Asenjo-Lobos C5, Cortes M6, Canon M7, Bardach A3, Comandé D3, Cardona A8
1Policy and Research, Health Systems Based on Primary Health Care, Pan American Health Organization. WDC, USA
2Servicio de Epidemiología Clínica y Salud Pública, Centro Cochrane Iberoamericano, Hospital de la Santa Creu i Sant Pau (UAB), Barcelona, Espana
3Argentine Cochrane Centre IECS, Institute for Clinical Effectiveness and Health Policy Buenos Aires. Argentina
4Instituto de Investigaciones, Fundación Universitaria Sanitas. Centro Colaborador de la Colaboración Cochrane, Bogotó D.C., Colombia
5Centro Rehabilitación Oral Avanzada e Implantología (CRAI) Universidad de Concepción (Centro Adherido Chileno de la Red Cochrane Iberoamericana) - Chile
6Facultad de Medicina, Centro Colaborador de la Colaboración Cochrane, Universidad Católica de la Santísima Concepción. Chile
7Facultad de Medicina, Fundación Universitaria Sanitas, Bogotó D.C., Colombia
8Grupo Oncología Clínica y Traslacional, Instituto de Oncología, Fundación Santa Fe de Bogotó, Bogotó D.C., Colombia
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.