Comprehensive Evaluation of Adherence to Therapy, Its Associations, and Its Implications in Patients With Chronic Myeloid Leukemia Receiving Imatinib

Abstract

Background: Adherence to oral therapy over a long period is important for optimal outcomes in chronic myeloid leukemia (CML).

Methods: Patients in the chronic phase of CML (taking imatinib for ≥ 6 months) were assessed by the 8-item Morisky Medication Adherence Scale and European Organisation for Research and Treatment of Cancer Quality of Life (QoL) Questionnaire (C30 and CML 24). Patients were classified as adherent (score 8) and nonadherent (score ≤ 7) as per the 8-item Morisky Medication Adherence Scale.

Results: Among 221 patients (male to female ratio = 133:88; median age, 39 (18-65) years; median duration of imatinib, 4 years), the nonadherence rate was 55% (N = 122/221). None of the demographic parameters, including occupation, education status, income, and availability of caregiver, were associated with nonadherence. QoL scores, especially the symptom scores associated with side effects of imatinib, significantly differed between adherent and nonadherent patients. Multivariate analysis revealed global health status as the sole predictor of adherent behavior (odds ratio, 0.978; 95% confidence interval, 0.963-0.994; P = .007). A higher proportion of adherent patients achieved deeper molecular responses. Low QoL was associated with nonadherence to imatinib in patients with CML.

Conclusions: It is likely that increased long-term symptom burden due to side effects of imatinib could contribute to nonadherence. Interventions targeting individual components of QoL may improve adherence and outcomes in CML.

Keywords: CML; India; Molecular response; Outcomes; Quality of life.