Systematic review of cross-national drug utilization studies in Latin America: methods and comparability.

Purpose: We systematically review the cross-national drug utilization studies performed in Latin America (LA) in order to analyze the methods applied and assess the validity of the data to ensure the comparability.

Methods: A systematic search in Medline, Embase, and BIREME was performed. Drug utilization studies including LA countries and comparing drug exposure data on volume were included. The data validity was judged independently by two authors as having low, medium, high, or unclear risk of bias.

Results: Out of 1191 articles, 25 were kept for full text reading. Finally, five studies were selected. Eight different Latin American countries were involved in the comparisons. The selected studies analyzed wholesale data from a private research company collecting information from the private healthcare sector. In three studies, a high risk of bias in the extrapolation method applied was identified. In one study, a risk of data collection bias was detected. The most frequent limitation detected by the original authors was related to the unavailability of information from the public sector in LA.

Conclusion: Drug utilization studies comparing data cross-nationally are scarce in LA. In general, validity of the comparisons is hampered by a potential risk of extrapolation bias given the lack of available data on drug consumption from the public healthcare sector. Setting up systems to remediate this situation is a future challenge for researchers and (supra)national authorities in the region.