# Hydroxyurea utilization among individuals with sickle cell disease in Tennessee: a pooled analysis of claims data

## TL;DR

This study examines how hydroxyurea use affects healthcare outcomes for people with sickle cell disease in Tennessee, finding that higher use is linked to fewer hospital visits and lower mortality.

## Contribution

The study provides new evidence on the relationship between hydroxyurea adherence and healthcare utilization in a large, diverse population with sickle cell disease.

## Key findings

- Hydroxyurea adherence was associated with reduced hospitalizations and emergency department visits.
- Higher hydroxyurea use was linked to lower mortality rates among individuals with sickle cell disease.
- Adherence to hydroxyurea showed a dose–response relationship with acute healthcare utilization, except in 18–25-year-olds.

## Abstract

Hydroxyurea reduces severe disease among individuals living with sickle cell disease (SCD). These individuals experience high acute care utilization, but the associations between patterns of hydroxyurea utilization and healthcare utilization are not well investigated.

This study aimed to determine the association between hydroxyurea use and healthcare utilization among individuals with SCD in Tennessee (TN).

We conducted a population-based, retrospective cohort study of individuals with SCD using secondary data analysis of Tennessee Medicaid, Medicare, and BlueCross BlueShield of Tennessee (BCBS-TN).

A total of 4,901 individuals with SCD were included in the study.

Hydroxyurea adherence was estimated using the medication possession ratio (MPR).

The incidence rate ratios of hospitalizations, emergency department visits, and mortality were calculated using negative-binomial models.

The prevalence of hydroxyurea prescription dispensation for the state was low (21% for TennCare, 21% for Medicare, and 17% for BCBS-TN). In TennCare and BCBS-TN, those younger than 18 had more hydroxyurea utilization, and individuals with HbSS or HbSβ0 thalassemia filled more hydroxyurea than those with other subtypes (30.5% in TennCare and 23.4% in BCBS-TN). The MPR for the entire state was 19.7%. There was a dose–response relationship between hydroxyurea adherence and the incidence of acute healthcare utilization, except in 18–25-year-olds. We also found lower mortality in those with higher hydroxyurea adherence.

In our pooled statewide analysis, hydroxyurea MPR was low. Higher hydroxyurea use was associated with decreased acute healthcare utilization and lower mortality. Interventions to support patient adherence and provider prescribing are required to improve health outcomes among individuals with SCD.