Risk of bias assessment of clinical trials published in iberoamerican urological journals.

Objectives: To assess the risk of bias of clinical trials published in iberoamerican indexed journals from January 1, 2008 to December 31, 2012.

Methods: We performed a descriptive study based on the clinical trials published from January 1st 2008 to December 31st 2012 in the iberoamerican urological journals. We assessed the risk of bias by the Cochrane tool. We used descriptive statistics in Stata 13 and Revman 5.2 to create the risk of bias graphs within and across studies.

Results: We identified 41 clinical trials: 21 trials in the International Brazilian Journal of Urology, seven trials in Actas Urológicas Españolas, six trials in Archivos Españoles de Urología, two trials in the Boletin Mexicano de Urología, four trials in Revista Mexicana de Urología and one trial in Revista Urología Colombiana. Most of these trials had unclear risk for the generation of the randomization (selection bias), the allocation concealment (selection bias) and the blinding (performance and detection). There was low risk of bias for incomplete results data (Attrition bias) and selective notification (notification bias). High risk of bias was found in other possible sources of bias, mainly because of low sample size.

Conclusions: Based on the Cochrane risk of bias tool assessment, most of the published trials do not accomplish an adequate description of the methods. We should also be aware that most of the trials lack an adequate sample size calculation that limits the power of these trials. We recommend better description of the methods for randomization, and increasing the sample size to improve the quality of the trials published in urologic iberoamerican journals.