Predictors for development of critical illness amongst older adults with COVID-19: Beyond age to age-associated factors.

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 ≥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 ≥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.

Appropriateness of blood culture: A comparison of practices between the emergency department and general wards.

BACKGROUND: The decision to perform a blood culture is influenced by factors, such as the pretest probability of bacteremia, resource availability and individual clinician's preference. The lack of formal guidelines results in inconsistencies in practices and an inappropriate or overuse of blood cultures. The primary aim of this study is to compare the rate of positive blood cultures in the emergency department (ED) and general ward. The secondary aim of this study is to analyze factors associated with a positive blood culture. METHODS: We compared 200 consecutive patients in the ED with 200 consecutive patients with first blood cultures done within 24 h of admission from ED to the general ward. We analyzed the clinical characteristics, proportion of positive blood cultures, and variables associated with a positive blood culture. RESULTS: The percentage of positive blood cultures was 13.5% (n = 27) in the ED group, compared with 6.0% (n = 12) in the general ward group. Contamination rates were higher in the ED compared to general ward (4% vs 0.5%). Heart rate and rigors were independently associated with a positive blood culture in a multivariate logistic regression model. CONCLUSION: There was a lower rate of positive blood cultures in the general ward group. Reasons may include a lower threshold for performing blood cultures in the general ward, and prior antibiotics in the ED reducing the sensitivity of blood cultures taken in the general ward. Adherence to clinical decision rules and education of junior staff are needed to improve the efficiency of blood culture taking practices.