A high comorbidity burden among veterans hospitalized with COVID-19 infection is associated with longer admissions, higher rates of rehospitalization, and increased illness severity. These study results were published in Open Forum Infectious Diseases.
In an ongoing, prospective cohort study, researchers examined early outcomes of COVID-19 infection among hospitalized veterans at 15 Department of Veterans Affairs medical centers between February 2021 and June 2022. Researchers enrolled 1 COVID-19-negative participant for every 1 COVID-19-positive participant by hospitalization status (inpatient vs outpatient). Study data were collected on days 0, 3, 7, 14, 21, 28, and months 3, 6, 12, 18, and 24 after enrollment through questionnaires and electronic health records. The primary outcomes were illness severity, total number of hospital days within 60 days, and the rate of rehospitalization within 60 days. The 3 outcomes were assessed via multinomial logistic regression, negative binomial, and Cox proportional hazards models, respectively.
Among 542 participants included in the analysis, 140 were positive for COVID-19 infection and vaccinated, 152 were positive for COVID-19 infection and unvaccinated, and 250 were negative for COVID-19 infection. The 3 cohorts primarily consisted of men who were older and White.
Inpatients who are older or have a greater number of comorbidities, even if vaccinated, warrant close attention since they are at increased risk of worse outcomes after SARS-CoV-2 infection.
High Charlson comorbidity index (CCI) scores (≥5) were noted among 44% of COVID-19-positive participants who were vaccinated, 19% of COVID-19-positive participants who were unvaccinated, and 30.4% of COVID-19 negative participants.
The researchers evaluated illness severity outcomes among COVID-19-positive participants, controlling for age, sex, vaccination status, and calendar period of enrollment. Results showed that every 1-unit increase in CCI score was associated with increased risk for severe illness relative to mild illness (adjusted odds ratio [aOR], 1.21; 95% CI, 1.01-1.45).
Further analysis showed that total number of hospital days was higher among vaccinated COVID-19-positive participants compared with COVID-19-negative participants (adjusted incident rate ratio [aIRR], 1.55; 95% CI, 1.26-1.91). Other factors associated with higher total number of hospital days included older age (aIRR, 1.10; 95% CI, 1.03-1.17) and higher CCI score (aIRR, 1.06; 95% CI, 1.03-1.10).
Rehospitalization within 60 days occurred among 44% of COVID-19-positive participants who were vaccinated and 25% of COVID-19-negative participants (adjusted hazard ratio [aHR], 1.86; 95% CI, 1.28-2.69). As with outcomes of illness severity and total number of hospital days, higher CCI scores were also associated with increased risk for rehospitalization (aHR, 1.07; 95% CI, 1.01-1.12).
Limitations of this study include the relatively small sample size, the predominance of men, and the possibility that COVID-19 infection was not the primary cause of hospitalization among all participants in the COVID-19-positive cohorts.
The researchers noted, “Inpatients who are older or have a greater number of comorbidities, even if vaccinated, warrant close attention since they are at increased risk of worse outcomes after SARS-CoV-2 infection.”
Disclosure: Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
This article originally appeared on Infectious Disease Advisor