INTRODUCTION: Older adults with COVID-19 have disproportionately higher rates of severe disease and mortality. It is unclear whether this is attributable to age or attendant age-associated risk factors. This retrospective cohort study aims to characterize hospitalized older adults and examine if comorbidities, frailty and acuity of clinical presentation exert an age-independent effect on COVID-19 severity. METHODS: We studied 275 patients admitted to the National Centre of Infectious Disease, Singapore. We measured: 1)Charlson Comorbidity Index(CCI) as burden of comorbidities; 2)Clinical Frailty Scale(CFS) and Frailty Index(FI); and 3)initial acuity. We studied characteristics and outcomes of critical illness, stratified by age groups (50-59,60-69 and &#8805;70). We conducted hierarchical logistic regression in primary model(N = 262, excluding direct admissions to intensive care unit) and sensitivity analysis(N = 275): age and gender in base model, entering CCI, frailty (CFS or FI) and initial acuity sequentially. RESULTS: The &#8805;70 age group had highest CCI(p<.001), FI(p<.001) and CFS(p<.001), and prevalence of geriatric syndromes (polypharmacy,53.5%; urinary symptoms,37.5%; chronic pain,23.3% and malnutrition,23.3%). Thirty-two (11.6%) developed critical illness. In the primary regression model, age was not predictive for critical illness when a frailty predictor was added. Significant predictors in the final model (AUC 0.809) included male gender (p=.012), CFS (p=.038), and high initial acuity (p=.021) but not CCI or FI. In sensitivity analysis, FI (p=.028) but not CFS was significant. CONCLUSIONS: In hospitalized older adults with COVID-19, geriatric syndromes are not uncommon. Acuity of clinical presentation and frailty are important age-independent predictors of disease severity. CFS and FI provide complimentary information in predicting interval disease progression and rapid disease progression respectively.
Predictors for development of critical illness amongst older adults with COVID-19: Beyond age to age-associated factors