Admission phenotype and 180-day mortality in older adults hospitalized with SARS-CoV-2 infection.

Introduction In older inpatients, SARS-CoV-2 positivity does not always indicate that COVID-19 is the cause of admission. Aim To compare clinical profiles and 180-day mortality between older adults admitted for typical COVID-19 and those with incidental SARS-CoV-2 infection. Material and methods This retrospective cohort study included 306 hospitalized patients aged ≥60 years with SARS-CoV-2 infection. Admission phenotype was manually adjudicated as typical COVID-19 respiratory disease or incidental SARS-CoV-2 infection. Baseline characteristics, multimorbidity, CRP, IL-6, D-dimer, SpO2, and 180-day mortality were analyzed. Mortality was assessed using Kaplan–Meier curves and multivariable logistic regression. Results and discussion The cohort included 266 typical and 40 incidental admissions. Multimorbidity was common in both groups (79.2% vs 89.7%; p = 0.122). Typical admissions had lower SpO2 and higher CRP at admission (75.2 vs 34.8 mg/L; p = 0.007), whereas incidental admissions had higher D-dimer concentrations (2.2 vs 1.1 ng/mL; p = 0.016). Crude 180-day mortality was higher in the typical COVID-19 group (42.9% vs 22.5%; p=0.014). After adjustment for age and multimorbidity, incidental phenotype was independently associated with lower mortality odds (OR = 0.40; 95% CI: 0.18–0.89; p = 0.027). Conclusions Typical COVID-19 and incidental SARS-CoV-2 infection are distinct geriatric admission phenotypes. Typical COVID-19 admissions are associated with higher 180-day mortality, independent of baseline multimorbidity.