Differences in Post-Acute Care Healthcare Expenditures After Hospitalization Due to Influenza or Covid-19 Infection

ABSTRACT

Rationale The long-term consequences of SARS-CoV-2 infection on patients' health are increasingly recognized. It is unknown if these consequences are common to all severe viral infections or are specific to SARS-CoV-2. A syndrome of persistent exertional dyspnea has been described after influenza infection. Here, we describe patterns in healthcare expenditures for patients hospitalized for either influenza or COVID-19. Methods: We used an all-payer administrative dataset comprised of coding and billing data from over 600 healthcare entities in the United States that use a financial analytics platform by Strata Decision Technology, a private company. The de-identified analytic sample included patients aged 18 years or older who were admitted to a hospital between January 2018 and February 2021 with either an ICD-10 code for COVID-19 (COVID-19 hospitalizations) or for influenza (influenza hospitalizations). Linear regression models were used to evaluate the relationship between infection type (COVID-19 or influenza) and total post-acute healthcare expenditures (post-acute expenditures), defined as cumulative charges 1 month or more after hospitalization. The dependent variable was log-transformed post-acute expenditures and the independent variables included health system classification (academic, multi-site, single site community, and children's) and size (based on operating budget), pre-hospitalization charges, date of admission (spline), gender, and US census region. Analyses were stratified by age (18-44, 45-64, and 65+) and need for ventilation during acute hospitalization. Results: Of the 98222 patients included in our analysis, 83278 (84.8%) were COVID-19 hospitalizations and 14944 (15.2%) were influenza hospitalizations. This patient cohort was 52% female, and contained 36039 (36.7%) patients from the Midwest, 20102 (20.5%) from the Northeast, 32031 (32.6%) from the West, and 9514 (9.7%) from the South. Mean length of stay was 6.78 days. Patients with COVID-19 were more likely to receive mechanical ventilation during hospitalization (3.8%) than patients with influenza (1.8%). Compared to influenza, linear model results suggest that COVID-19 was associated with similar or lower postacute expenditures (see table 1). Results are presented separately by ventilation status to accommodate potentially differential relationships between infection severity, post-acute expenditures, and length of stay in the two patient populations. Conclusion: In previously hospitalized patients, post-acute expenditures are similar between COVID-19 (March 2020-February 2021) and influenza (January 2018- February 2021). Despite the high burden of healthcare utilization related to post-acute sequelae of COVID-19, these findings suggest that individual healthcare expenditures after acute COVID-19 infection are similar to severe influenza infection.