Objective: To analyse susceptibility/risk of suffering COVID19 among adults with distinct underlying medical conditions. Methods: Cohort study (population-based) including 79,083 people >=50 years-old in Tarragona (Southern Catalonia, Spain). At study start (01/03/2020) baseline cohort characteristics (demographic, previous comorbidities, chronic medications and vaccinations history) were recorded. Primary outcome was laboratory-confirmed COVID19 incurred in cohort members throughout 01/03/2020-30/06/2020. Risk of suffering COVID19 was evaluated by Cox regression, estimating multivariable hazard ratios (HRs) adjusted for age/sex and previous comorbidities. Results: Across study period, 536 laboratory-confirmed COVID19 cases were observed (mean incidence: 39.5 cases per 100,000 persons-week). In multivariable-analysis, age/years (HR: 1.01; 95% CI: 1.00-1.02; p=0.050), nursing-home (HR: 20.19; 95% CI: 15.98-25.51; p<0.001), neurological disease (HR: 1.35; 95% CI: 1.03-1.77; p=0.029), taking diuretics (HR: 1.39; 95% CI: 1.10-1.75; p=0.006), antiplatelet (HR: 1.36; 95% CI: 1.05-1.76; p=0.021) and benzodiazepines (HR: 1.24; 95% CI: 1.00-1.53; p=0.047) significantly increased risk; while smoking (HR: 0.57; 95%CI: 0.41-0.80; p=0.001), angiotensin converting enzyme inhibitors (HR: 0.78; 95% CI: 0.61-1.00; p=0.048), angiotensin II receptor blockers (HR: 0.70; 95%CI: 0.51-0.96; p=0.027) and statins (HR: 0.75; 95% CI: 0.58-0.96; p=0.025) were associated with reduced risk. Among non-institutionalised persons, cancer, renal and cardiac disease appeared also related to increased risk, whereas influenza vaccination was associated with reduced risk. Conclusion: In a setting with relatively low incidence of COVID19 across the first wave of pandemic period, age, nursing-home residence and multiple comorbidities appear predisposing for COVID19 among middle-aged/older adults. Conversely, statins, angiotensin-receptor blockers/inhibitors and influenza vaccination were related with decreased risk. KEYWORDS: Coronavirus; SARS-COV-2; COVID19; Incidence; Risk.