Clinical Burden and Health Care Resource Utilization Associated With Managing Sickle Cell Disease With Recurrent Vaso-occlusive Crises in England.

Abstract

Purpose: Sickle cell disease (SCD) is an inherited red blood cell disease caused by a mutation in the gene encoding the β-subunit of adult hemoglobin that leads to hemolysis, anemia, vaso-occlusive crises (VOCs), morbidity, and mortality. This study provides a real-world assessment of the clinical burden and health care resource utilization (HCRU) associated with SCD with recurrent VOCs in England.

Methods: This retrospective study linked primary care records from the Clinical Practice Research Datalink database with secondary care records from the Hospital Episode Statistics database to identify patients with SCD with recurrent VOCs between July 1, 2008, and June 30, 2018. A VOC was defined as SCD with crisis, acute chest syndrome, or priapism. Eligible patients had SCD, ≥2 VOCs/year in any 2 consecutive years after a diagnosis of SCD, and ≥1 year of follow-up data from the index date. Patients were exact matched with 5 controls from the general population in the databases. Demographics were assessed at index. Mortality, clinical complications, and HCRU were summarized during follow-up.

Findings: After applying eligibility criteria, 1117 patients with SCD with recurrent VOCs and 5585 controls were included in the study. Mean age at index was 25 years in both groups. The proportion of deaths (3.67% vs 0.68%; P < 0.001) and mortality rate (0.78 deaths per 100 person-years vs 0.16 deaths per 100 person-years) were substantially higher in patients with SCD with recurrent VOCs versus matched controls. Mean (standard deviation [SD]) age of death in patients with SCD with recurrent VOCs who died during the follow-up period was 40.17 (14.09) years. The mean (SD) rate of VOCs for patients with SCD with recurrent VOCs was 5.84 (12.50) per patient per year (PPPY) during follow-up. Compared with matched controls, patients with SCD with recurrent VOCs had substantially higher mean [SD] rates PPPY of inpatient hospitalizations (7.59 [14.50] vs 0.32 [2.71]), prescriptions (31.06 [60.62] vs 7.58 [27.77]), and outpatient visits (9.60 [10.69] vs 1.78 [4.18]). Older patients and those with increased numbers of VOCs had increased mortality, frequency of clinical complications, and HCRU.

Implications: Despite currently available care, patients with SCD with recurrent VOCs in England have increased mortality, substantial clinical complications, and significant HCRU driven by VOCs and hospitalizations. Elevated mortality and clinical complications in patients with SCD with recurrent VOCs highlight the need for novel therapies in this space.