Assessment of Medication Adherence and Its Relationship with Disease Uncertainty and Socioeconomic Factors in Patients with Breast Cancer

Introduction: Cancer treatment is often associated with various complications. Medication adherence is influenced by numerous psychological, demographic, socioeconomic, and disease-related factors. This study aimed to evaluate the status of medication adherence and the factors affecting it in patients with breast cancer in Kerman, Iran. Methods: This cross-sectional study included patients with breast cancer who were followed up at a private oncology specialist's office and Javadalaimeh Clinic in Kerman, Iran, in 2024. Data were collected using a three-part questionnaire comprising demographic and treatment-related characteristics, the Medication Adherence Rating Scale (MARS), and the Mishel Uncertainty in Illness Scale. Results: The mean MARS score was 7.44 ± 1.93, and 161 of 234 participants (68.8%) demonstrated high medication adherence. Higher illness uncertainty ( P < 0.001) and family income below the subsistence level ( P = 0.017) were significantly associated with lower medication adherence. Illness uncertainty was the strongest predictor of reduced medication adherence. Conclusion: Although most patients with breast cancer exhibited high medication adherence, greater illness uncertainty and lower family income were significantly associated with lower adherence. These findings highlight the importance of addressing psychological and socioeconomic factors to improve medication adherence in this population.