An exploratory study of citations in systematic reviews of randomized trials published in Latin American journals

The prevalence of inclusion of randomized controlled trials published in Latin American journals has not been evaluated yet. This study explores the extent to which randomized trials published in Latin American medical journals are cited and used in systematic reviews.

We did a descriptive observational study on randomized trials published in MEDLINE-indexed Latin American journals from 2010 to 2015. The primary outcome was the inclusion of these trials in systematic reviews. The secondary outcome was the total number of citations each trial received, as reported by Google Scholar.

Twenty-nine journals were selected. After searching these journals, we found 135 trials that fulfilled the inclusion criteria accounting for 2% of all research articles published in these journals. Of these, 55 (41%) were included in 202 systematic reviews. Of the nine most-cited randomized trials by systematic reviews and meta-analyses, only two were published in Spanish. Nine received zero citations by any article type. Most had small sample sizes.

The overall impact of randomized controlled trials published in Latin American journals is low. Little funding, language bias and small sample sizes may explain the low inclusion in systematic reviews and meta-analyses.