ALBERT

Description: Background Adherence to the prescribed dose of tyrosine kinase inhibitors (TKIs) is critical to maximize treatment effectiveness in chronic myeloid leukemia (CML). While patient-centered outcome studies are lacking in this area, literature has shown that a significant proportion of patients report both intentional and unintentional non-adherence. Objective The main objective of this multivariate analysis was to identify risk factors that might predict intentional non-adherence to TKIs in CML. Methods The CML Advocates Network, connecting 79 CML patient groups from 63 countries, conducted an international project investigating patterns of medication-taking behaviors of CML patients, supported by CML investigator groups in Germany, Italy and France. We sought to demonstrate the relationship between 16 factors and adherence in this multinational cohort. A web-based survey was launched in 12 languages, enrolling CML patients from Sept 2012 to Jan 2013. The identical questionnaire was provided to a cohort of patients recruited in clinics in France, Germany and Italy, returned by patients in a pre-stamped envelope to an independent data center. Questions included potential factors associated with non-adherence as well as on patients' perception of disease and treatment burden. Based on previous literature and on clinical relevance, a pool of 16 candidate factors, potentially predicting intentional non-adherence, was selected for analysis. These included: frequency of CML medication, co-payment for CML treatment, and current TKI therapy. Patients who reported having skipped intentionally one or more doses over the last year were considered as “intentional non-adherers”. Univariate logistic regression analysis was performed to examine the impact of pre-selected candidate factors on the probability of intentional non-adherence. Two multivariate models were fitted based on line of therapy received by patients (i.e. first line and second or greater lines of therapy). Results This patient-led study is the largest study conducted to date on the influencers of non-adherence in CML. Overall, 2546 adult CML patients (47.6% female) under TKI treatment from 79 countries responded to the survey. 2151 patients responded online, 395 questionnaires were returned on paper. No significant difference on intentional non-adherence was observed between paper or online responses. Median age of patients was 51 years (range 18-96) and median time from diagnosis was 4 years (0-27). Overall, 51.6% of all respondents reported having missed at least one dose unintentionally over the last year, and 19.5% did so intentionally. This analysis regards the intentional non-adherent population (n=490). Of those, 60% were on imatinib, 20% on nilotinib, 14% on dasatinib, 6% on other TKIs. Several factors predicted intentional non-adherence in univariate analysis, including education level (P=0.016) and co-payment for TKIs (P=0.005). For patients on first line TKI (n=1551), the following factors independently predicted a higher likelihood of being intentional non-adherers: younger age (P=0.015), longer time since diagnosis (P