BACKGROUND: Guideline-recommended therapy for metastatic non-small cell lung cancer (mNSCLC) encourages evidence-based treatment; however, there is a knowledge gap regarding the influence of guideline-recommended initiation of therapy on outcomes and cost. OBJECTIVE: To investigate if lack of guideline-recommended initiation of first-line systemic therapy was associated with worse patient outcomes and increased costs for patients with mNSCLC. METHODS: In this retrospective analysis, 1,344 Medicare patients with mNSCLC were identified from Humana data. Performance status (PS) was imputed using procedure, diagnosis, and durable medical equipment codes pre-index. Guideline-recommended initiation of therapy was defined as >= 1 cycle of National Comprehensive Cancer Network-recommended first-line therapy based on age and PS or targeted therapies regardless of age and PS. Demographics and clinical characteristics were compared by guideline-recommended initiation of therapy. A Cox model assessed factors associated with 6-month mortality. End-of-life quality of care indicators included hospital admission and oncology infusions 30 days preceding death and were evaluated using logistic regression models. A generalized linear model assessed the relationship between guideline-recommended initiation of therapy and total health care costs in the 6 months post-index controlling for clinical, demographic, and treatment characteristics. Logistic models for inpatient stays and emergency department visits were also evaluated. RESULTS: Guideline-recommended therapy initiation was observed in 75.5% of patients. Patients not initiating guideline-recommended therapy were older, with a mean (SD) age of 72.5 (6.7) versus 71.2 (6.2) years (P = 0.001), and more frequently identified as having a low-income subsidy (30.0% vs. 16.4%; P < 0.001). Among the 24.6% of patients who died >= 6 months post-index, a greater percentage had not initiated guideline-recommended therapy (28.8% vs. 23.2%; P = 0.040). In adjusted models, PS (not initiation of guideline-recommended therapy) was predictive of mortality (patients with poor PS had an 84% higher probability of death [P = 0.014]). Among decedents, 64.2% were hospitalized, and 33.9% had an oncology-related infusion within 30 days of death, with no differences by guideline-recommended initiation of therapy. These end-of-life quality indicators were not associated with guideline-recommended initiation of therapy in adjusted models. Overall, 47.5% of patients who initiated guideline-recommended therapy were hospitalized compared with 55.0% of patients who did not (P = 0.026). Patients initiating guideline-recommended therapy had higher post-index total and oncology-related health care costs and fewer hospitalizations. In models, these differences in costs and hospitalizations were not associated with initiation of guideline-recommended therapy. CONCLUSIONS: Most patients initiated guideline-recommended therapy, with no differences in mortality and quality of care at the end of life by guideline-recommended initiation of therapy, though adherence beyond treatment initiation was not assessed. Unadjusted hospitalization rates were lower and costs were higher for patients who initiated guideline-recommended therapy. These differences were no longer observed after risk adjustment, suggesting that they may have been influenced by patient characteristics, disease progression, and subsequent treatment decisions. Copyright (c) 2018, Academy of Managed Care Pharmacy. All rights reserved.
