Self-medication with NSAIDs and purchase of branded and over-the-counter medicines: Analysis of a national survey in Peru

Background: This study aimed to determine the association between self-medications with nonsteroidal anti-inflammatory drugs (NSAIDs) and the purchase of branded and over-the-counter medications in Peru. Design and methods: This secondary analysis used a representative survey of Peru from 2014 to 2016. The exposure variable was self-medication with NSAIDs, defined as “the purchase of NSAIDs for oneself without a prescription.” The outcome was the purchase of branded and over-the-counter medications. Crude prevalence ratios (cPR) and adjusted prevalence ratios (aPR) with their respective 95% confidence intervals (95% CI) were calculated. Results: Of the total of 2158 participants, 52.80% were women with an average age of 40.24 years. The prevalence of self-medication with NSAIDs was 68.21%, whereas the rates of purchasing branded and over-the-counter medications were 63.78% and 13.16%, respectively. The adjusted Poisson regression analysis showed an association between self-medication with NSAIDs and the purchase of branded (aPR = 1.18; 95% CI: 1.12–1.25; p < 0.001) and over-the-counter (aPR = 2.38; 95% CI: 1.95−2.90; p < 0.001) medications. Conclusions: Approximately 7/10 users who self-medicate with NSAIDs chose branded medications, whereas nearly 1/5 opt for over-the-counter medications. Self-medication with NSAIDs was associated with a higher likelihood of purchasing branded and over-the-counter medications.