Status and Influencing Factors of OTC Medicine Use for Self-Medication in Cold and Cough: A Cross- Sectional Survey in Japan

Background Understanding the factors that influence the over-the-counter (OTC) medicine use can provide important information on guiding the proper use of OTC medicines and reducing national medical care expenditure. This study investigates the status of self-medication with OTC medicines for colds and coughs in Japan after COVID-19 pandemic and explores the associated factors. Methods This study is an online cross-sectional survey conducted from April 25 to June 26, 2024. The status of self-medication behaviors against colds and coughs in Japan and covariates of social background and psychological scales were collected. Associations between them were analyzed using multivariate logistic regression. Subgroup and sensitivity analyses were conducted to validate the robustness of the findings. Results This study included 1,086 participants. 43.6% of the participants would take OTC medicines from the onset of colds and coughs. The proportion of seeking healthcare after symptoms lasted one week was 61.7%. Over 80% of the participants would strictly follow the usage instructions. Factors associated with seeking healthcare within one week included age, living area, education level, marital status, insurance type, having an underlying disease, regular doctor visits, and extraversion. When considering dosage adherence, the agreeableness trait was determined to be a positive factor, whereas having a child or children was a negative factor. For the awareness of expiration dates for OTC medicines, eHEALS, which indicated internet literacy for searching health-related information, was found to be a significant and robust positive factor. Conclusions A high proportion of Japanese were found to use OTC medicines for colds and coughs. Most participants demonstrated a strong awareness of proper OTC use. To further promote OTC medicine, it is important to address the key factors found in this study.