[Evaluation of incidence and risk profile for suffering Covid-19 infection by underlying conditions among middle-aged and older adults in Tarragona.]

Vila-Córcoles, Ángel; Ochoa-Gondar, Olga; Torrente-Fraga, Cristina; Vila-Rovira, Ángel; Satué-Gracia, Eva; Hospital-Guardiola, Immaculada; de Diego-Cabanes, Cinta; Gómez-Bertomeu, Frederic; Basora-Gallisà , Josep

OBJECTIVE Population-based data on the current Covid-19 pandemic is scarce. This study investigated incidence and risk to suffer Covid-19 by baseline underlying conditions in people ≥50 years in Tarragona region across march-april 2020. METHODS Population-based retrospective cohort study involving 79,071 adults ≥50 years-old in Tarragona region (Southern Catalonia, Spain). Cohort characteristics (age, sex, residence, vaccinations history and comorbidities) were established at baseline, and Covid-19 cases occurring between 01/03/2020-30/04/2020 were registered. Cox regression analysis calculating Hazard ratios (HRs) adjusted by age, sex and comorbidities was used to estimate risk for Covid-19. RESULTS Across study period, 1,547 cohort members were PCR tested (22.6% positive) and 367 were presumptive cases without PCR tested. Considering PCR-confirmed Covid-19, incidence (per 100,000 persons-period) was 441 overall (248, 141, 424, 1,303 and 3,135 in 50-59, 60-69, 70-79, 80-89 and ≥90 years-old, respectively; 380 in men and 497 in women; 259 in community-dwelling and 10,571 in nursing-home). By comorbidities, maximum incidence emerged among persons with neurological disease (2,723), atrial fibrillation (1,348), chronic renal failure (1,050), cardiac disease (856), respiratory disease (798) and diabetes (706). Lower incidence appeared in rheumatic diseases (230) and smokers (180). In multivariable analysis focused on community-dwelling individuals (N=77,671), only cardiac disease (HR: 1.47; 95% CI: 1.01-2.15; p=0.045) and respiratory disease (HR: 1.75; 95% CI: 1.00-3.02; p=0.051) were associated with an increased risk, whereas smoking (HR:0.43; 95% CI: 0.25-0.74; p=0.002) and influenza vaccinated (HR: 0.63; 95% CI: 0.43-0.92; p=0.015) appeared associated with a decreased risk. CONCLUSIONS Apart of increasing age and nursing-home residence, chronic respiratory and cardiac disease appear at increased risk for suffering covid19. This study investigated population-based incidence of Covid-19 infection by underlying conditions among adults ≥50 years in Tarragona (Southern Catalonia, Spain) across two first months pandemic period.