Association of Loneliness and Health Literacy with Overuse of Over-the-counter Drugs in Patients with COVID-19 in Japan

Loneliness is associated with medication use and that health literacy influences medication adherence. However, limited knowledge exists regarding the self-medication of over-the-counter (OTC) drugs among patients with COVID-19 during the pandemic. Therefore, this study aimed to examine the relationship between loneliness, health literacy, and OTC self-medication in home care settings during the Omicron BA.5-Dominant Wave (the 7th COVID-19 wave, July-September 2022) in Japan. Individuals aged 20 to 49 years were randomly selected from the web panel of a research company (Macromill, Inc.). Participants who had contracted COVID-19 during the Omicron BA.5-Dominant Wave were asked to complete the Three-Item Loneliness Scale (TIL) and the 14-item Health Literacy Scale (HLS-14). Logistic regression analysis was conducted using disregard for OTC drug package inserts and OTC drug overuse as objective variables. Valid responses were obtained from 197 men and 180 women. Among OTC drug users (n =282), 18% disregarded the OTC drug package inserts, and 9% used more than the recommended amount of OTC drugs. Disregarding OTC drug package inserts was significantly associated with HLS-14 score ≤51, indicating low health literacy (odds ratio (OR): 2.43, 95% confidence interval (CI): 1.26-4.79, P = 0.008). OTC drug overuse was significantly associated with TIL score ≥6, indicating high loneliness (OR: 3.97, 95% CI: 1.64-10.63, P = 0.002). The findings of this study highlight the importance of communication in addressing the disregard of OTC drug package inserts and the overuse of OTC drugs in patients with COVID-19, taking into account both health literacy and loneliness.