Impact of Health Care Funding on Compliance and Survival in Patients with Chronic Myeloid Leukemia in the Era of Tyrosine Kinase Inhibitors: A Single Institution Experience

Background: Health care funding has been shown to have an effect on the outcomes of several hematological malignancies. There hasn't been enough data on the impact of health care funding and compliance on the outcomes of chronic myeloid leukemia (CML) in the era of Tyrosine kinase inhibitors (TKIs).

Methods: We conducted a retrospective review of patients diagnosed with CML between January 1, 2000 and June 30, 2014. Several factors such as age, sex, race, health care funding, distance traveled to access health care facility (less than or greater than 100 miles), compliance with medications and clinic visits, white blood cell count at the time of diagnosis, time to response and dates of death or last follow up were collected by review of electronic health records. Impact of compliance with medications and clinic visits, and health care funding status on overall survival were the main outcomes of the study. Chi-Square or fisher's exact test were used where appropriate to assess the association among variables and multivariate cox regression model was used to assess the effect of variables on survival of these patients.

Results: A total of 93 patients were included in the review, most recent follow up being in June 2015. Median age of the patients at diagnosis was 50 years. In a multivariate cox regression analysis, compared to patients with Medicaid, those with Medicare (HR=0.311, 95% CI: 0.11-0.89) and private health care funding (HR=0.32, 95% CI: 0.32-0.99) had an increased survival where as lack of funding had no impact on survival (HR=0.52, 95% CI: 0.2-1.36). White blood cell count (WBC) of less than 80,000/microL at diagnosis predicted an increased survival (HR=0.43, 95% CI: 0.20-0.91) as compared to patients with WBC greater than 80,000/microL, whereas age at diagnosis, sex, race, achievement of major molecular response, compliance with oral TKIs or clinic visits had no impact on survival. There was a trend towards increased compliance with TKIs in patients with Medicare and private funding when compared to those with Medicaid and no health care funding (p=0.09). Patients with Medicaid and private funding were more compliant with their clinic visits (84% and 62% respectively) when compared to those with Medicare and no funding (51.6% and 37% respectively, p=0.02). Patients who traveled less than 100 miles to reach health care facility were more compliant with oral chemotherapy (TKI) than those who had to travel farther, (62.5% vs. 55%, p=0.46) whereas patients who traveled far to access health care were more compliant with clinic visits (64% vs. 53%, p=0.26). However, neither of these findings was statistically significant.

Conclusion: Health care funding and WBC at diagnosis seem to have a significant impact on overall survival in patients with CML. There seems to be a trend towards increased compliance with TKIs in patients with Medicare and private funding as compared to those with Medicaid and no funding. Equal access to health care through patient assistance programs could probably explain the non-inferior survival in patients with no funding. Further studies are needed to validate these findings in a larger patient population.