Study Design and Study Population

We designed a nested case-control study based on the cohort involved in an ongoing study (Pilot Study on the Burden of Influenza in the Nursing Home) being conducted in the Istituto AltaVita-IRA nursing home in the city of Padua, Italy. For this pilot study, 418 residents underwent a multidimensional assessment by experienced geriatric physicians between October and December 2019. Of that sample, 382 individuals were still residents in the nursing home in March 2020, 76 of whom became infected with SARS-CoV-2 up to May 15, 2020, and were, therefore, recruited as cases in the present study. We selected 76 controls matched to the cases by age ±3 years from those residents who were not infected by SARS-CoV-2 and were still alive up to June 2020. Among the cases, 20 residents (26.3%) deceased from March to July 2020, and 56 underwent the post-COVID-19 assessment (the study flow-chart is shown in Supplementary Figure 1). The study was approved by the local Ethics Committee of the Istituto AltaVita-IRA nursing home, and participants (or their next of kin) gave their written consent to participate in the study.

Flow chart of the study.