The risk factors of COVID-19 in a longitudinal population-based study

Abstract

The present longitudinal study aims to investigate the risk factors for getting COVID-19 in a population aged 50 to 74 years. Data were collected from Shahroud Eye Cohort Study and the electronic system of COVID-19 in Shahroud, northeast Iran. Participants were followed for about 13 months and predisposing factors for COVID-19 infection were investigated using log binomial model and by calculation of relative risks. From the beginning of the COVID-19 outbreak in Shahroud (February 20, 2020) to March 26, 2021, out of 4394 participants in the Eye Cohort Study, 271 (6.1%) were diagnosed with COVID-19 with a positive Reverse Transcription Polymerase Chain Reaction test on two nasopharyngeal and oropharyngeal swabs. Risk factors for getting COVID-19 were included male gender (Relative Risk (RR) = 1.51; 95% Confidence Intervals (CI), 1.15-1.99), BMI over 25 (RR = 1.03; 95% CI, 1.01-1.05) and diabetes (RR = 1.31; 95% CI, 1.02-1.67). Also, smoking (RR = 0.51; 95% CI, 0.28-0.93) and education (RR = 0.95; 95% CI, 0.92-0.98) had reverse associations. In conclusion men and diabetic patients and those who have BMI over 25, should be more alert to follow the health protocols related to COVID-19 and priority should be given to them considering COVID-19 vaccination.