Clinical Frailty Scale (CFS) Indicated Frailty is Associated with Increased In-Hospital and 30-Day Mortality in COVID-19 Patients: A Systematic Review and Meta-Analysis

Abstract Background: The concept of frailty provides an age-independent, easy-to-use tool for risk stratification. We aimed to summarize the evidence regarding the use of frailty tools in COVID-19, assessing the risk of frail patients for in-hospital and 30-day mortality, intensive care unit (ICU) admission, and length of hospitalization (LOH).Methods: The protocol was prospectively registered via PROSPERO (CRD42021241544). Studies reporting on frailty in COVID-19 patients were eligible. We compared in-hospital and 30-day mortality, lengths of stay and ICU admission in frail and non-frail COVID-19 patients. We also compared average frailty in COVID-19 survivors and non-survivors. MEDLINE (via PubMed), EMBASE, Scopus, CENTRAL, and Web of Science were searched up to 3 February 2021 with terms related to COVID-19 and frail*. Search, selection, data extraction and risk of bias assessment were conducted in duplicate by two independent review authors. The QUIPS tool was used for the risk of bias assessment. Odds ratios (OR) and weighted mean differences (WMD) were calculated with 95% confidence intervals (CI) using a random effect model. Heterogeneity was assessed using the I 2 and χ 2 tests.Results: From 1693 records identified, 27 were included in the qualitative and 21 in the quantitative synthesis. Clinical Frailty Scale (CFS) was used in 24 studies, the Hospital Frailty Risk Score (HFRS) by one and the Frail Non-Disabled questionnaire by another one. One study reported both CFS and HFRS. We found that frail patients (CFS 5–9) compared to non-frail patients (CFS 1–4) have a higher risk for both in-hospital (OR: 2.77; CI: 1.86–4.15) and 30-day mortality (OR: 1.47; CI:1.05–2.06). Frail patients (CFS 5–9) were less likely to be admitted to ICU (OR 0.05, CI: 0.01–0.16). Statistical heterogeneity was not present for CFS 5–9 30-day mortality OR and ICU admission OR (CFS 1–3 vs 4–9), and was moderate for in-hospital mortality WMD. Quantitative synthesis for LOH was not feasible. Most studies carried a high risk of bias.Conclusions: As determined by CFS, frailty is strongly associated with in-hospital and 30-day mortality; hence, investigating its use in deciding on ICU admission further in COVID-19 is warranted.