Risk Factors for Non-Adherence to Pharmacist or Non-Pharmacist Explanations on Preoperative Medication Discontinuation: A Retrospective Japanese Study

Purpose: The risk factors for non-adherence to pharmacist or non-pharmacist explanations of preoperative medication discontinuation are unknown. The primary outcome of this study was to determine whether the final explainer's occupation was a risk factor for non-adherence. The secondary outcomes were to determine the risk factors for non-adherence after limiting the departments or adjusting for age. Patients and Methods: We retrospectively examined the data (including patient age, sex, prescription medications, comorbidities, presence of roommate, and number of days between receiving explanation and surgery) of 1132 patients on medications that could affect surgery at a Japanese university hospital between April 1, 2017, and March 31, 2020. The primary endpoint was whether the occupation of the last person explaining medication discontinuation to the patient was an independent risk factor for non-adherence (age >= 65 years vs <65 years). Secondary endpoints included subgroup analyses in urological, gastrointestinal, and otolaryngological areas, as well as a sensitivity analysis (age as a continuous variable) to confirm the validity of the primary endpoint results. A multivariate binary logistic regression identified independent non-adherence risk factors. Results: The main analysis showed that discontinuing two or more medications was a risk factor for non-adherence (adjusted odds ratio (AOR): 1.67; 95% confidence interval (CI): 1.13-2.47; p = 0.01). However, in analyses coordinated by department (urological, gastrointestinal, and otolaryngological), >= 65 (versus <65) years of age was determined as a risk factor for increased nonadherence (AOR: 2.27, 95% CI: 1.11-4.63; p=0.024). Age-adjusted analysis (continuous variables) showed similar results to the primary endpoint (AOR: 1.68, 95% CI: 1.14-2.49, p = 0.009). Conclusion: Two or more medications, and not the final explainer's occupation, were associated with pre-surgery medication nonadherence. To prevent non-adherence, pharmacists and non-pharmacists should educate patients about preoperative medication discontinuation. These findings could help identify high -risk non-adherence patients.