Over-the-Counter Medicine (OTC) Attitudes and Medication Adherence in Patients with Chronic Diseases: A Structural Equation Modelling Analysis

This study aimed to evaluate over-the-counter medicine (OTC) use, OTC attitudes, and medication adherence (MA) in patients with chronic diseases. Data were collected from May to September 2023, and 276 patients with chronic diseases participated. OTC use, OTC attitudes, and MA were assessed using a questionnaire. One-way ANOVA was used to examine differences in OTC-related parameters and MA. The path analysis method was used to test “H1: OTC attitudes affect MA in patients with chronic diseases.” A total of 52.2% of the participants used OTC. More positive OTC attitudes were associated with lower MA scores. The patients who disagreed with the statement "OTC have no side effects or negative effects" had 0.402 times less MA than those who were not sure (t=2.409; p=0.016). Even though the patients had negative attitudes toward OTC in general, they had an optimistic view of being encouraged to use OTC. The results of this study revealed that OTC use is common, and positive attitudes toward OTC decrease MA in patients with chronic diseases. However, patients with high MA are willing to support OTC use. Patients with chronic diseases may need information on OTC. Nurses and other healthcare professionals can take the potential OTC use of patients, drug-drug interactions, or drug-food interactions into account. According to the needs of patients, structured education programs can be implemented in care.