Patients’ Beliefs about Medicines, Adherence and Potential Drug-Drug Interactions in Cancer Treatment: A Tripartite Study at Ayder Comprehensive Specialized Hospital, Mekelle, Ethiopia

Abstract

Background: Patients’ beliefs about medications, adherence to therapy, and of drug-drug interactions (DDIs) are critical in optimizing cancer treatment outcomes and ensuring safety. Understanding these factors can enhance adherence and reduce the risks associated with polypharmacy. Objective: This study assessed beliefs about medicines, medication adherence, and the prevalence of DDIs among cancer chemotherapy patients at Ayder Comprehensive Specialized Hospital in Mekelle, Ethiopia. It also explored factors influencing these outcomes and the relationships between them. Methods: A cross-sectional study was conducted from March 2024 to March 2025 involving 385 ambulatory cancer patients aged ≥18 years. Participants were randomly selected and evaluated using the Beliefs about Medicines Questionnaire (BMQ) and the 8-item Morisky Medication Adherence Scale (MMAS-8). Data analysis employed SPSS version 26 with descriptive statistics, logistic regression, and Pearson’s correlation. Significance was set at p ≤ 0.05. Results: The study analyzed data from 385 patients (mean age 45.6 years; 74.3% female). Most were married (60.8%), had no formal education (44.2%), and low monthly income (71.4% earned ≤1500 ETB). Among them, 94.3% had been diagnosed within five years, 90.1% had no comorbidities, and 60% had non-breast cancers. BMQ findings showed that 92.7% believed in the necessity of their medications, but 67.3% had concerns about harm. MMAS-8 results revealed 71.7% adherence, with 94.8% reporting they rarely forget doses. 88.3% of cases of major DDI were those between 5-fluorouracil and leucovorin. Adherence was correlated positively with necessity and negatively with concerns and harm. Conclusion: The study revealed a high level of perceived necessity and moderate adherence, higher than reported in comparable settings. However, concerns about medication and the high prevalence of DDIs highlight the need for improved patient counseling and medication safety practices.