Hydroxyurea Use and Clinical Outcomes Among Adults with Severe Sickle Cell Disease: A retrospective Cohort Study using Electronic Health Record Data

Author(s)

Siang-Hao Cheng, BS Pharm1, Enrico M. Novelli, MD, MS2, Terri V. Newman, PharmD, MS1, Kangho Suh, PharmD, PhD1;
1University of Pittsburgh School of Pharmacy, Pittsburgh, PA, USA, 2University of Pittsburgh School of Medicine, Pittsburgh, PA, USA

Presentation Documents

OBJECTIVES: To evaluate (1) factors associated with Hydroxyurea (HU) use and (2) compare time to vaso-occlusive crisis (VOC) between HU users and non-users among adults with severe sickle cell disease (SCD).
METHODS: This retrospective cohort study analyzed the University of Pittsburgh Medical Center's electronic health records (2014-2024). We included adults (≥18 years) who had one inpatient or 2 outpatient records (>30 days apart) with an SCD diagnosis and ≥3 VOCs in a year, both using ICD-9/10 codes, who are guideline recommended to receive HU. HU use was assessed within 90 days after the third VOC event (index date). Baseline characteristics were measured 6 months pre-index. Multivariable logistic regression analyzed factors associated with HU use within 90 days. Using patients' HU use status within 90 days, time to VOC was compared between groups from 90-365 days post-index using Cox proportional hazards models, both in the overall cohort and in patients with Sickle Cell Anemia (SCA, defined as homozygous HbSS or HbS/β⁰ thalassemia).
RESULTS: Among 540 patients in our cohort, HU utilization rate was 18.9% at 90 days post-index, with 38.8% in SCA patients (n=232) and <5% in other genotypes. Significant factors associated with HU use included SCA genotype (Odds Ratio [OR]=6.85, 95% Confidence Interval [95% CI]: 3.37-13.93), younger age (OR=0.96, 95% CI: 0.93-0.99 per year), pulmonary complications (pneumonia, URTI, pulmonary embolism, pulmonary hypertension OR=2.85, 95% CI: 1.57-5.19), and opioid use (OR=6.6, 95% CI: 1.91-22.95). In SCA patients, significant factors were younger age (OR=0.95, 95% CI: 0.92-0.99), pulmonary complications (OR=3.0, 95% CI: 1.52-5.91), and opioid use (OR=6.2, 95% CI: 1.26-29.03). After baseline covariate adjustment, no significant differences in time to VOC were observed between groups.
CONCLUSIONS: Despite proven benefits in reducing VOC-related complications, HU utilization rates remain suboptimal, particularly among non-SCA genotypes. Patients using HU tend to have more severe disease manifestations and be younger.

Conference/Value in Health Info

2025-05, ISPOR 2025, Montréal, Quebec, CA

Value in Health, Volume 28, Issue S1

Code

CO84

Topic

Clinical Outcomes

Topic Subcategory

Clinical Outcomes Assessment, Relating Intermediate to Long-term Outcomes

Disease

SDC: Rare & Orphan Diseases, SDC: Systemic Disorders/Conditions (Anesthesia, Auto-Immune Disorders (n.e.c.), Hematological Disorders (non-oncologic), Pain)

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