COVID-19 in Adults with Sickle Cell Disease: Data from Cerner Real-World Database

Introduction

Sickle cell disease (SCD) is the most common inherited hemoglobinopathy and is estimated to affect more than 100,000 Americans. A voluntary clinical reported registry of COVID-19 infections in patients with SCD reported both high hospitalization rates (69%) and case fatality rates (7%) (Panepinto, 2020), but only reported data from March 20-May 21, 2020. We hypothesize that the rate of hospitalizations among patients with SCD and COVID 19 decreased with time as vaccinations became available and COVID-19 treatment improved.

We report on all patients, both ambulatory and hospitalized, with SARS-CoV-2 and SCD at institutions contributing data to the Cerner Real-World Data^TM (CRWD) database. The CRWD is a de-identified cloud-based data source of electronic health records from more than 100 health systems in the United States.

Methods

Exempted retrospective review was approved by ChristianaCare IRB. We obtained access to the CRWD, which included data for all patients with SARS-CoV-2 and SCD as documented by ICD 10 D57.XX and positive lab result or ICD-10 U07.X from 3/1/2020-10/15/2021. Those with sickle cell trait were excluded. The final dataset included 896 patients, after excluding patients <18 years and those without prior health care encounters. We used Wilcoxon rank sum test to compare the characteristics between ambulatory and hospitalized patients and examined the trend in hospitalizations between 2020 quarter 1 and 2021 quarter 3.

Results:

The final data set included 896 adult patients, 371 of whom were hospitalized. There was no difference in sex or insurance status between the 2 groups. Those hospitalized were more likely to have at least 1 AHRQ comorbidity (80.3% vs. 72.8% p=0.01), notably coronary artery disease, hypertension, renal failure, and congestive heart failure and be considered immunocompromised as defined by AHRQ (reference?). The median length of stay [IQR]was 5 days [3;9]. A total of 35/371 (9.43%) patients were admitted to the ICU and 25/371 (6.74%) were treated with invasive ventilation for a median of 15 days; 28/371 patients died (7.5%) and 5 were discharged to hospice care.

When evaluated by quarter, the hospitalization rate peaked in 2020 Q2 at 46.9% then remained stable with an average over the next 5 quarters of 40.9%.

Discussion

Ambulatory patients were slightly younger and had fewer prior encounters, potentially representing less severe sickle cell phenotypes. Death rate is similar to other COVID cohorts. Geographic variability of patients- some zip code areas had relatively few, corresponds to areas with low patient density. Contrary to what we expected, after a peak in 2020Q2, the rate of hospitalizations remained stable until 2021Q3 at approximately 41%.

There are several limitations to this study: it only draws from Cerner EMR institutions, representing a 26% market share and does not include data from the Omicron wave which started after October 2021. The vaccination status relied on import of external data and is likely incomplete. Finally, we could not adequately gauge severity of COVID-19 disease given notable variations in institutional resources.

Guarino:Novartis: Consultancy.