ABSTRACT
OBJECTIVES: 1. to evaluate mortality risk excess in the population residing in nursing care homes (NCHs) compared to non-NCHs before the COVID-19 outbreak; 2. to verify if the outbreak modified risk excess; 3. to estimate the COVID-19 impact; 4. to ascertain incidence-mortality relationship. DESIGN: cohort study. SETTING AND POPULATION: Mantua and Cremona provinces (Lombardy Region, Northern Italy) - included in ATS Val Padana - with COVID-19 incidence rate 7.5 and 16.9, respectively. Inhabitants aged >= 75 years as of 1st January 2018, 2019, and 2020 (three cohorts), stratified in NCH or not. The indicators calculated were: 1. rate ratio (RR) for NCH vs non-NCH, adjusted by gender, age, chronic diseases number, at least 1 hospitalisation, at least 1 Emergency room access in the previous year, for 2018, 2019, and 2020; 2. adjusted RR, 2019 and 2020 vs 2018, both sub-cohorts (i.e., NCH and non-NCH). MAIN OUTCOME MEASURES: first four-month period mortality of the considered years. RESULTS: aproximately 100,000 inhabitants by year, 7% in NCH. In the 2020 first four-month period, 4,343 deaths occurred of which 45% in NCH. RR in NCH population vs non-NCH for the year 2018 was 2.13 (95%CI 1.94-2.34); for the year 2019 was 2.70 (95%CI 2.43-3.00); for the year 2020 was 6.98 (95%CI 6,49-7,50). Adjusted RR for NCH population in 2020 vs 2018 was 2.22 (95%CI 2.05-2.42) in the whole ATS Val Padana; 1.58 (95%CI 1.40-1.77) in Mantua Province; 2.93 (2.62-3.27) in Cremona Province. Adjusted RR in non-NCH population in the year 2020 vs 2018 was 1.59 (95%CI 1.48-1.70) in the whole ATS; 1.34 (95%CI 1.23-1.46) in Mantua Province; 1.89 (95%CI 1.73-2.07) in Cremona Province. CONCLUSIONS: the NCH population experienced an excess risk mortality compared to non-NCH before the COVID-19; this excess increased during the outbreak. In 2020, in NCHs the risk was more than double compared to the 2018 risk, while in non-NCHs it rose approximately by 60%. The gap between NCHs/non-NCHs COVID-19 impact was higher in Cremona than in Mantua.