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
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.
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)