Examining the Effect of Hydroxyurea Treatment on Acute Care Spending and Utilization among Patients with Sickle Cell Disease

Abstract

Background: Sickle cell disease (SCD) is one of the most common inherited diseases in the U.S. and disproportionately affects African Americans and Hispanic Americans. People with SCD suffer acute pain crises and chronic pain throughout the lifespan and since disease cure is often unattainable, most turn to intensive and costly disease management, often with particularly high emergency care use. Hydroxyurea (HU), an inexpensive therapeutic drug, has proven to be effective at reducing pain crises. However, HU is underutilized for a variety of reasons including lack of insurance coverage, misperceptions and negative beliefs, and lack of provider awareness of guidelines. This paper aims to quantify how healthcare utilization, spending, and pain crises in SCD patients change before and after prescription of hydroxyurea, as well as estimate the potential averted burden if those not prescribed hydroxyurea were to be placed on the treatment regimen. Methods: MarketScan Commercial Claims and Encounters databases person-specific information on healthcare utilization, healthcare spending, prescriptions, and diagnoses from 2016 to 2019 was aggregated into 90-day periods. 2-tailed t-tests were used to compare their mean outcomes in care utilization, spending, and pain crises per 90 days, pre and post receipt of that prescription and negative binomial regressions were run to estimate mean outcomes over 5, 90-day time periods. Control SCD patients who had never received a prescription for hydroxyurea were matched 1:1 using propensity score matching to the previously established treated group on age, sex and genotype. T-tests and regressions were repeated to compare mean outcomes between control and treated groups. The ratio of change in outcome pre and post HU prescription among treated patients was then applied to the control group to estimate the potential averted care utilization, pain, and spending if the control received the treatment. Results: 7,793 patients between the ages of 0 and 65 with a diagnosis of SCD from ICD-10 with a minimum of 1 year data coverage were selected, of whom 25.7% (n =2008) received a prescription for hydroxyurea at any point. 631 patients met the inclusion criteria for at least 90 days prior to initial prescription of hydroxyurea and 360 days post prescription. Prior to initiating treatment, hydroxyurea-treated patients had worse outcomes per 90 days with an estimated total of 5.4 (95% confidence interval 5.0-5.9) visits, $15,691 (13,088 – 18,812) net pay, and 1.2 (1.1-1.4) pain crises, compared to matched controls who in cross section had 1.7 (1.6-1.8) total visits, $4,319 (3,750 – 4,975) total net pay, and 0.3 (0.3-0.3) pain crises. Though outcomes among those initiating hydroxyurea remained significantly higher than controls, across care utilization, spending, and pain crises, patient 90-day outcomes were significantly lower post hydroxyurea initiation, in all types of care except outpatient visits and outpatient net pay, and the greatest declines were in inpatient settings. Interpretation: SCD patients have high care utilization, spending, and pain outcomes. Those treated with hydroxyurea may experience greater disease severity, but this study indicates that if hydroxyurea were more widely utilized, their outcomes may be improved, and a large health and financial burden could be averted.