Development and validation of an electronic database-based frailty index to predict mortality and hospitalization in a population-based study of adults with SARS-CoV-2

Paola Rebora; Carlo Alberto Scirè; Giuseppe Occhino; Francesco Bortolan; Olivia Leoni; Francesco Cideni; Alberto Zucchelli; Emanuele Focà; Alessandra Marengoni; Giuseppe Bellelli; Maria Grazia Valsecchi

doi:10.3389/fmed.2023.1134377

Development and validation of an electronic database-based frailty index to predict mortality and hospitalization in a population-based study of adults with SARS-CoV-2

Front Med (Lausanne). 2023 May 12:10:1134377. doi: 10.3389/fmed.2023.1134377. eCollection 2023.

Affiliations

¹ Bicocca Center of Bioinformatics, Biostatistics and Bioimaging, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
² School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
³ Regione Lombardia, General Directorate for Welfare, Regional Epidemiological Observatory Organizational Unit, Directorate General for Health, Milan, Italy.
⁴ Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
⁵ Division of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
⁶ Acute Geriatric Unit San Gerardo Hospital, Monza, Italy.

Abstract

Background: Electronic health databases are used to identify people at risk of poor outcomes. Using electronic regional health databases (e-RHD), we aimed to develop and validate a frailty index (FI), compare it with a clinically based FI, and assess its association with health outcomes in community-dwellers with SARS-CoV-2.

Methods: Data retrieved from the Lombardy e-RHD were used to develop a 40-item FI (e-RHD-FI) in adults (i.e., aged ≥18 years) with a positive nasopharyngeal swab polymerase chain reaction test for SARS-CoV-2 by May 20, 2021. The considered deficits referred to the health status before SARS-CoV-2. The e-RHD-FI was validated against a clinically based FI (c-FI) obtained from a cohort of people hospitalized with COVID-19 and in-hospital mortality was evaluated. e-RHD-FI performance was evaluated to predict 30-day mortality, hospitalization, and 60-day COVID-19 WHO clinical progression scale, in Regional Health System beneficiaries with SARS-CoV-2.

Results: We calculated the e-RHD-FI in 689,197 adults (51.9% females, median age 52 years). On the clinical cohort, e-RHD-FI correlated with c-FI and was significantly associated with in-hospital mortality. In a multivariable Cox model, adjusted for confounders, each 0.1-point increment of e-RHD-FI was associated with increased 30-day mortality (Hazard Ratio, HR 1.45, 99% Confidence Intervals, CI: 1.42-1.47), 30-day hospitalization (HR per 0.1-point increment = 1.47, 99%CI: 1.46-1.49), and WHO clinical progression scale (Odds Ratio = 1.84 of deteriorating by one category, 99%CI 1.80-1.87).

Conclusion: The e-RHD-FI can predict 30-day mortality, 30-day hospitalization, and WHO clinical progression scale in a large population of community-dwellers with SARS-CoV-2 test positivity. Our findings support the need to assess frailty with e-RHD.

Keywords: COVID-19; care transitions; community; health services; hospital; public health.