Risk Factors for Hospitalization and Mortality due to COVID-19 in Espírito Santo State, Brazil

Predictors of hospitalization and severe disease due to breakthrough SARS-CoV-2 infection in fully vaccinated individuals

Objective

We aimed to identify risk factors for hospital admission and severe disease among fully vaccinated (FV) individuals with COVID-19. Further, we investigated if risk factors for hospitalization and severe disease are similar between unvaccinated (UV) and vaccinated individuals.

Methods

This was a multicenter, observational cohort analysis from a large regional healthcare system in metro Detroit using electronic health record data to evaluate risk factors for hospitalization and severe COVID-19 disease. Vaccination data were retrieved using electronic medical records linked to our statewide immunization database. Consecutive adult FV and UV patients with a primary admission diagnosis of COVID-19 were included in the comparative analysis. Partially vaccinated patients and patients who had received a booster dose were excluded. The primary outcome of this study was hospital admission and severe disease inclusive of intensive care unit (ICU) admission, mechanical ventilation, or death.

Results

Between December 15, 2020 and December 19, 2021, 20,584 emergency department visits met our inclusion criteria. Among these, 2005 (9.7%) visits consisted of FV individuals, 18,579 (90.3%) were UV, and 40.3% of UV and 52.7% of FV required hospitalization with similar (12.7% and 12.6%, respectively) rates of severe disease. Hospitalized UV patients with severe disease were younger than their FV counterparts (49.5% <65 years vs. 13.5% p < 0.001). Risk factors for severe disease on UV and FV included age ≥65 years (UV: adjusted odds ratio [aOR] 1.49, 95% confidence interval [CI] 1.28-1.73, p < 0.001 and FV: aOR 2.50, 95% CI 1.44-4.36 p = 0.001) and weighted Elixhauser score >10 (UV: aOR 9.11, 95% CI 6.92-12.00, p < 0.001 and FV: aOR 6.04, 95% CI 2.68-13.26, p < 0.001). However, only on UV status, body mass index (BMI) ≥30 kg/m2 was associated with increased odds of severe disease (aOR 2.59, 95% CI 2.09-3.22, p < 0.001).

Conclusions

FV patients with breakthrough SARS-CoV-2 infection who require hospitalization and have severe disease are older and have more medical comorbidities compared to UV patients. When comparing risk factors for severe disease between UV and FV individuals, FV status is particularly associated with reduced risk among patients with a BMI ≥30 kg/m2 and a moderate number of medical comorbidities, regardless of age, highlighting the importance of vaccination in these particularly vulnerable groups.

Hospitalised versus outpatient COVID-19 patients' background characteristics and comorbidities: A systematic review and meta-analysis

This study aimed to systematically assess COVID-19 patient background characteristics and pre-existing comorbidities associated with hospitalisation status. The meta-analysis included cross-sectional, cohort, and case-series studies with information on hospitalisation versus outpatient status for COVID-19 patients, with background characteristics and pre-existing comorbidities. A total of 1,002,006 patients from 40 studies were identified. Significantly higher odds of hospitalisation were observed in Black individuals (OR = 1.33, 95% CI: 1.04-1.70), males (OR = 1.59, 95% CI: 1.43-1.76), and persons with current/past smoking (OR = 1.59, 95% CI: 1.34-1.88). Additionally, individuals with pre-existing comorbidities were more likely to be hospitalised [asthma (OR = 1.22, 95% CI: 1.02-1.45), COPD (OR = 3.68, 95% CI: 2.97-4.55), congestive heart failure (OR = 6.80, 95% CI: 4.97-9.31), coronary heart disease (OR = 4.40, 95% CI: 3.15-6.16), diabetes (OR = 3.90, 95% CI: 3.29-4.63), hypertension (OR = 3.89, 95% CI: 3.34-4.54), obesity (OR = 1.98, 95% CI: 1.59-2.46) and renal chronic disease (OR = 5.84, 95% CI: 4.51-7.56)]. High heterogeneity and low publication bias among all factors were found. Age was not included due to the large variability in the estimates reported. In this systematic review/meta-analysis for patients with COVID-19, Black patients, males, persons who smoke, and those with pre-existing comorbidities were more likely to be hospitalised than their counterparts. Findings provide evidence of populations with higher odds of hospitalisation for COVID-19.