Drug Adherence and Associated Factors in Patients with Systemic Sclerosis

Background: Systemic sclerosis (SSc) is a rare, chronic and disabling autoimmune disease. Disease-modifying antirheumatic drugs are the cornerstone and initial therapy in SSc. Although drug adherence is crucial for successful therapy, non-adherence is a substantial problem in some patients. Objectives: to identify the determinants of adherence to medications among Iraqi patients with SSc. Patients and Methods: This cross-sectional study included a total of 143 consecutive patients diagnosed as having SSc. Disease severity was determined according to Arabic version of the eight-item Morisky Medication Adherence Scale (MMAS-8). The following data was collected through the questionnaire: age, gender, body mass index (BMI), residence, socioeconomic status (SES), marital status, education level, employment, duration of SSc, type of SSc, self- dependence, medications, chronic comorbidities, satisfaction with treatment and presence of side effects. Results: The adherence rate was 40%. In Multivariate analysis, high educational level (OR=6.56, 95%CI=1.18-72.32, p= 0.041), and high SES (OR=25.3, 95%CI= 2.3-27.36, p= 0.008) were significantly associated with increased drug adherence. On the other hand, unemployment (OR=0.25, 95%CI= 0.07-0.87, p= 0.039), the presence of side effects (OR= 0.19, 95%CI=0.04-0.98, p= 0.048), and patient treatment dissatisfaction (OR=0.31, 95%CI=0.7-0.77, p= 0.025) were independent risk factors for non-adherence. Conclusions: Sixty percent of studied patients with SSc attending Baghdad Teaching Hospital were of low medication adherence. High education level and higher socioeconomic status are significantly associated with increased treatment adherence in patients with SSc. Alternatively, unemployment, presence of drug side effects and treatment disssatisfaction were significantly associated with lower adherence rates in patients with SSc.