Predicting Medication Adherence in Sickle Cell Disease and Thalassemia in Oman: The Role of Beliefs and Fatigue.

PURPOSE: Patients with sickle cell disease and thalassemia require lifelong pharmacological management yet demonstrate persistently low medication adherence, with limited research on adherence predictors in Oman. This study aimed to assess medication adherence and identify its predictors, including fatigue and beliefs about medicines, among adults with sickle cell disease and thalassemia in Oman. PATIENTS AND METHODS: A cross-sectional descriptive correlational study was conducted at the National Hematology Center in Oman. A convenience sample of 233 adult patients completed three validated self-report instruments. Clinical data were extracted from medical records, and multiple linear regression was used to identify predictors of adherence. RESULTS: Most participants (91.8%) demonstrated low adherence (mean score 18.73 ± 3.56 out of 25). The regression model explained 34.5% of the variance in adherence (adjusted R2 = 0.316; F[10, 222] = 11.69; P <0.001). Significant predictors of poorer adherence were medication side effects (B = -1.90; P <0.001), frequency of hospitalization (B = -0.29; P =0.015), fatigue severity (B = -0.42; P =0.027), and harm beliefs about medicines (B = -0.31; P <0.001). A higher hemoglobin level was associated with better adherence (B = 0.44; P =0.004). CONCLUSION: Medication adherence is critically low among Omani patients with sickle cell disease and thalassemia. Healthcare professionals should address physical and psychosocial factors, including fatigue and misconceptions about medication harm, through individualized patient education and care plans to improve adherence and patient outcomes.