AUTHOR=Li Junjie , Wu Chen , Liu Kui , Lu Qinbao , Wang Xinyi , Ding Zheyuan , Fu Tianying , Jiang Xuefeng , Wu Haocheng 

TITLE=Monitoring OTC drug sales for early detection of respiratory infectious disease outbreaks

JOURNAL=Frontiers in Public Health

VOLUME=Volume 13 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2025.1661753

DOI=10.3389/fpubh.2025.1661753

ISSN=2296-2565

ABSTRACT=BackgroundIn recent years, over-the-counter (OTC) drug sales have emerged as a novel indicator for symptom monitoring, attracting widespread attention in public health research globally. This study conducted weekly monitoring of five OTC drug categories related to fever respiratory system diagnostic cluster (FRSDC) — antitussive/expectorant drugs, cold medications, antibiotics, pungent and cool exterior-relieving agents, and influenza medicine — in Pinghu City, Zhejiang Province, from 2022 to 2024. Concurrently, weekly FRSDC cases from Pinghu First People’s Hospital were collected.MethodsSpearman correlation analysis was used to quantify associations between OTC sales and FRSDC cases, while decision tree models evaluated the reliability of OTC data for early prediction of FRSDC trends.ResultsResults showed significant positive correlations between all five OTC drugs and FRSDC cases, with synchronous seasonal peaks in winter and spring (Spearman’s correlation coefficients ranged from 0.36 to 0.80, all p value ≤ 0.0001). Even when OTC drug sales preceded FRSDC cases by one or two weeks, strong correlations persisted (Spearman’s correlation coefficients ranged from 0.28 to 0.79, p value ≤ 0.0001). Decision tree analysis revealed that combining antitussive/expectorant drugs and influenza medications effectively predicted FRSDC epidemics with 83.33% accuracy (adjusted p value < 0.05).ConclusionThese findings suggest that monitoring OTC drug sales may serve as a useful early warning indicator for FRSDC, potentially aiding public health response and resource planning.