The Clinical and Economic Impact of Tyrosine Kinase Inhibitor Non-adherence in CML Patients within a US Integrated Healthcare System
Background: Chronic myelogenous leukemia (CML) accounts for 15% of all adult leukemias. Oral tyrosine kinase inhibitors (TKIs) have improved long-term survival significantly, but require strict adherence to the therapy to maximize effectiveness and minimize healthcare resource utilization.
Objective: To evaluate adherence to tyrosine kinase inhibitor therapy for incident CML patients, assess predictive factors associated with TKI non-adherence, evaluate laboratory monitoring rates and clinical response between adherent and non-adherent patients, and to compare healthcare resource utilization and costs between these groups.
Methods: Retrospective, observational cohort study using databases from the Kaiser Permanente health plan. Newly diagnosed CML patients were identified from 1/1/2007-12/31/2013 with index date as first incident TKI prescription fill. Adherence rates were measured over the 12-month post-index period using the MPR method, with an adherence threshold set at ≥85%. Patient characteristics and covariates were evaluated as potential contributors to non-adherence included age, gender, race, existing comorbidities, and healthcare utilization history. Laboratory monitoring included either hematologic, cytogenetic, or molecular testing during the post-index period. Clinical response/remission or no clinical response/progression was evaluated at the end of the 12-months and compared between the adherent and non-adherent groups. All-cause and CML-related healthcare resource utilization and costs were compared between the two groups as well.
Results: 194 CML patients were selected for inclusion into this study. Of the 194 patients, 123(63.4%) were found to be adherent to TKI therapy. Patient age, Deyo-Charlson Comorbidity index, pre-index hospitalization length of stay, and oral antidiabetic and antihyperlipidemic medications were found to be predictive factors associated with non-adherence. Adherent patients were more likely to be adherent to hematologic (100% vs 95.8%) and molecular/cytogenetic testing (91.1% vs 76.1%) than non-adherent patients. Of the 123 adherent patients, 106 (86.2%) achieved clinical response at the end of 12 months, compared to only 3 of the 71 (4.2%) non-adherent patients. Adherent patients had more all-cause and CML-related outpatient visits. Non-adherent patients had more all-cause and CML-related ER and hospital visits, higher hospitalization costs, and higher total mean costs.
Conclusion: The results confirm the importance of adherence to TKI therapy on clinical outcomes, healthcare resource utilization, and costs.
Recommended CitationAminimanizani, Pharm D, Amir, "The Clinical and Economic Impact of Tyrosine Kinase Inhibitor Non-adherence in CML Patients within a US Integrated Healthcare System" (2016). Master of Science in Applied Health Economics and Outcomes Research. Presentation 9.