Acute Care Utilization Is More Common in Patients with Sickle Cell Disease Who Have Chronic Complications and Chronic Pain: A Preliminary Report from the Escaped Trial

Background: We undertook a large multisite observational study collecting prospective data on health care utilization of patients with sickle cell disease (SCD). No prospective examination of symptom burden has been undertaken in SCD since the Cooperative Study of Sickle Cell Disease, and none in the modern era, since the widespread adoption of hydroxyurea therapy. The ESCAPED trial aims to compare patient centered outcomes following management of acute painful vaso-occlusive (VOC) events in the emergency department or in the infusion center. Here, we examine acute care utilization patterns in the first 223 subjects who have completed at least 6 months of follow-up and test determinants of utilization.

Methods: This is an ongoing, prospective cohort study that is recruiting across four sites (Baltimore, Cleveland, Milwaukee, and Baton Rouge). 500 adults with SCD who live in proximity to one of the study sites are being recruited and followed for 18 months. Data from visits for all acute, uncomplicated VOC are collected by chart review and patient interview. To ensure that acute visits are not missed, subjects are contacted on a monthly basis and where available statewide health information exchanges are queried. We tested for associations between subject characteristics upon enrollment and the number of acute visits during follow up using Poisson regression.

Results: The average length of follow-up to date is 9.1 months with a range of 6.1-14.2 months for the 223 subjects who have been enrolled for at least 6 months. The mean number of acute visits per month for uncomplicated VOC by the cohort was 0.65 (SD 0.87) with a median of 0.35, minimum of 0 and maximum of 5. 43 subjects have had no acute visits. 59% of the cohort are female, the mean age is 35.6 (SD 12.1). 74.3% have sickle cell anemia, 42% are employed and 52% reported having chronic pain. In a multivariate model, factors associated with an independent decrease in likelihood of an acute visit were increasing age, a history of leg ulcers, graduating high school and being employed, while an increase in likelihood of an acute visit was associated with chronic complications (kidney disease, retinopathy, stroke, and avascular necrosis) and chronic pain.

Conclusions: In this cohort, chronic complications like renal disease and AVN are associated with increased acute care visits. The association of chronic pain as an independent risk factor for acute visits, while intuitive, suggests that understanding and managing chronic pain may be central to mitigating pain and decreasing the need for acute care visits in the long term. The prevalence of chronic pain is high in this cohort, which likely well represents the contemporary US sickle cell community. The development of therapeutic strategies that address this significant complication of SCD are imperative if we are to both decrease symptom burden and the need for health care utilization in this population.