Characteristics of Brazilian clinical studies registered in ClinicalTrials.gov between 2010 and 2020.

AIM Evidence-based medicine uses high-quality methods, such as randomization and blinding prcedures, to support and inform clinical practice. The investigation of trials registered in clinical research databases may help understand the main characteristics of studies conducted in countries, such as Brazil. This study aimed to investigate the characteristics of Brazilian clinical trials registered in ClinicalTrials.gov in the last decade. METHODS Cross-sectional study performed in ClinicalTrials.gov database with clinical studies registered in Brazil between 2010 and 2020. A search was conducted in the database considering this period using filters for country (Brazil), start date (01 January 2010) and end date (date of the search: 07 May 2020). Descriptive statistics were used to characterize the studies. All analyses were conducted on Stata 14.2. RESULTS In total, 5368 studies were retrieved, which were mostly randomized (93.2%), blinded (63.2%), Phase III (48.7%) interventional studies (89.9%) with small sample sizes (57.2%) conducted with adults (93.0%) using drugs (42.7%) with a treatment purpose (77.3%), with funding from institutions other than the industry, the NIH, and the US Federal (71.3%). CONCLUSIONS The majority of Brazilian clinical studies used blinding and randomization procedures in the last 10 years. However, the predominance of trials with small sample sizes and with a focus on adult patients indicate the need of larger studies conducted with the pediatric population.