The Burden of Recurrent Vaso-Occlusive Crises in Ontario Sickle Cell Patients: Implications for Healthcare Management

A retrospective cohort Ontario study finds that patients with recurrent vaso‑occlusive crises (VOCs) face substantially higher complication rates, mortality, and healthcare utilization than matched controls.

The cohort included 859 patients with recurrent VOCs matched 1:3 to 2,577 controls; over follow-up the cumulative mortality proportion was 6.4% for the VOC group versus 0.35% for controls (incidence rates 0.86 vs 0.05 deaths per 100 person‑years). The VOC cohort also showed markedly higher complication prevalence and far greater inpatient and ED use, framing an urgent need for targeted management and prevention strategies.

At the population level, this real‑world evidence clarifies the scale of burden in Ontario and strengthens the observed link between VOC recurrence and downstream morbidity and system strain. Clinician interpretation should treat the measured risk as an operational input for resource allocation and outpatient prevention planning.

The recurrent‑VOC cohort had a mean (SD) age of 22.1 (14.4) years, 50.9% female representation, and a mean VOC rate of 3.2 events per person‑year; patients with recurrent VOCs were disproportionately from lower‑income neighbourhoods. Older age and higher VOC frequency correlated with greater burden across outcomes, linking socioeconomic disadvantage to higher recurrence risk within this cohort.

The analysis shows higher prevalence of both acute complications (for example, infections and gallstones) and chronic sequelae (including bone and joint complications, chronic pain, mental‑health and cardiopulmonary conditions). Mortality was significantly greater in the VOC group (mortality rate per 100 person‑years 0.86 vs 0.05); mean age at death in the VOC cohort was 39.2 years. These patterns are consistent with cumulative organ involvement as a likely driver of excess mortality, implicating age, VOC frequency, and end‑organ complications as central contributors to higher death rates.

Healthcare use was markedly greater in the recurrent‑VOC group: mean inpatient admissions 1.64 versus 0.04 per person‑year, mean hospital days 11.67 versus 0.17 per person‑year, and mean ED visits 3.0 versus 0.3 per person‑year (all P<0.0001). The study reports group means with associated P‑values. Overall, the utilization profile indicates concentrated resource intensity and cost burden across age and VOC‑frequency strata, supporting prioritization of prevention and care‑pathway redesign.