(98) Agreement on Drug Interactions from Two Drug Information System: An Analysis from a Population-Based Survey in The Brazilian Amazon, 2019

Publication Number: 429

Background: Drug information systems are commonly used by professionals to identify drug interactions and to ensure safe use of medications. There is a wide variety of sources which can provide different information, however, few real-world comparison of different drug interaction sources are available.

Objectives: To compare two subscription-based drug information system used to identify interactions in a cross-sectional population-based study.

Methods: This is a cross-sectional study based on a previous survey performed in Manaus, Amazonas Brazil, in 2019. Adults were included (≥18 years) who used two or more drugs in the fortnight of interview. We searched Micromedex and UpToDate databases to identify potential drug interactions. The primary outcome was the prevalence of potential drug interactions in each database. We described participants characteristics according to the outcomes and calculated weighted Kappa statistics to assess agreement on the presence of drug interaction, documentation and severity.

Results: Out of 752 adults that took two or more medicines, 344 participants had drug interaction in one or both databases and 212 had drug interaction in both databases. The prevalence of drug interactions was 43.8% (95% CI: 40.2, 47.3%) in UpToDate and 30.2% (95% CI: 26.9, 33.5%) in Micromedex. In both databases, higher frequencies of drug interaction were observed among people aged 45-59 (UpToDate: 54.2%; Micromedex: 36.6%), belonging to the lowest economic class (47.9%; 36.8%), presenting poor health status (55.8%; 36.1%), having chronic diseases (48.3%; 32.8%), and were using polypharmacy (77.9%; 52.0%). The agreement on drug interactions was fair (Kappa=0.631). As for severity (Kappa=0.398) and documentation (Kappa=0.311), the agreement was poor.

Conclusions: The compared databases showed slight agreement on the identification of potential drug interactions and relevant differences on the severity and documentation classifications. Both systems charge for access and would have the resources to provide higher quality and more accurate information. More investments in evidence gathering are needed to better support health care professionals on drug interaction decisions.