Stratification of the risk of developing severe or lethal Covid-19 using a new score from a large Italian population: a population-based cohort study

• Published in: BMJ open Vol. 11; no. 11; p. e053281
• Main Authors: Corrao, Giovanni, Rea, Federico, Carle, Flavia, Scondotto, Salvatore, Allotta, Alessandra, Lepore, Vito, D'Ettorre, Antonio, Tanzarella, Cinzia, Vittori, Patrizia, Abena, Sabrina, Iommi, Marica, Spazzafumo, Liana, Ercolanoni, Michele, Blaco, Roberto, Carbone, Simona, Giordani, Cristina, Manfellotto, Dario, Galli, Massimo, Mancia, Giuseppe, Bellentani, Donata, Ceccolini, Carla, Feo, Angela De, Mariniello, Rosanna, Visca, Modesta, Magliocchetti, Natalia, Romano, Giovanna, Lora, Antonio, Pisanti, Paola, Zanini, Rinaldo, Skrami, Edlira, Cantarutti, Anna, Compagnoni, Matteo Monzio, Pugni, Pietro, Davoli, Marina, Martino, Mirko Di, Lallo, Adele, Vuillermin, Giuliana, Bernardo, Alfonso, Frusciante, Anna, Belotti, Laura, Palma, Rossana De, Lenarda, Andrea Di, Prezza, Marisa, Fusco, Danilo, Marinacci, Chiara, Leoni, Olivia, Pizzi, Simone, Gallo, Lolita, Attolini, Ettore, Luca, Giovanni De, Francesconi, Paolo, Rizzuti, Carla, Avossa, Francesco, Vigna, Silvia, Dondi, Letizia, Martini, Nello, Pedrini, Antonella, Piccinni, Carlo, Cosentino, Mimma, Marvulli, Maria Grazia, Maggioni, Aldo
• Format: Journal Article
• Language: English
• Published: London British Medical Journal Publishing Group 18-11-2021; BMJ Publishing Group LTD; BMJ Publishing Group
• Series: Original research
• Subjects: Codes; Cohort analysis; Comorbidity; Coronaviruses; COVID-19; COVID-19 vaccines; health policy; Health services; Immunization; Infections; Intensive care; Pandemics; Patients; Population; Population-based studies; Public Health; Regions; Severe acute respiratory syndrome coronavirus 2; Italy
• ISSN: 2044-6055; 2044-6055
• DOI: 10.1136/bmjopen-2021-053281

ObjectivesTo develop a population-based risk stratification model (COVID-19 Vulnerability Score) for predicting severe/fatal clinical manifestations of SARS-CoV-2 infection, using the multiple source information provided by the healthcare utilisation databases of the Italian National Health Service.DesignRetrospective observational cohort study.SettingPopulation-based study using the healthcare utilisation database from five Italian regions.ParticipantsBeneficiaries of the National Health Service, aged 18–79 years, who had the residentship in the five participating regions. Residents in a nursing home were not included. The model was built from the 7 655 502 residents of Lombardy region.Main outcome measureThe score included gender, age and 29 conditions/diseases selected from a list of 61 conditions which independently predicted the primary outcome, that is, severe (intensive care unit admission) or fatal manifestation of COVID-19 experienced during the first epidemic wave (until June 2020). The score performance was validated by applying the model to several validation sets, that is, Lombardy population (second epidemic wave), and the other four Italian regions (entire 2020) for a total of about 15.4 million individuals and 7031 outcomes. Predictive performance was assessed by discrimination (areas under the receiver operating characteristic curve) and calibration (plot of observed vs predicted outcomes).ResultsWe observed a clear positive trend towards increasing outcome incidence as the score increased. The areas under the receiver operating characteristic curve of the COVID-19 Vulnerability Score ranged from 0.85 to 0.88, which compared favourably with the areas of generic scores such as the Charlson Comorbidity Score (0.60). A remarkable performance of the score on the calibration of observed and predicted outcome probability was also observed.ConclusionsA score based on data used for public health management accurately predicted the occurrence of severe/fatal manifestations of COVID-19. Use of this score may help health decision-makers to more accurately identify high-risk citizens who need early preventive or treatment interventions.