Risk factors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections: a nationwide population-based study

The coronavirus disease 2019 (COVID-19) has rapidly turned into a public health emergency worldwide; however, the risk factors for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been well-described. We aimed to identify the clinical risk factors for SARS-CoV-2 infections in Korea, where social distancing and face masks have been strongly recommended. The data of individuals who underwent the reverse transcription polymerase chain reaction test for SARS-CoV-2 between January 3 and May 31, 2020 were retrieved from the Health Insurance Review and Assessment Service dataset. We used multivariable logistic regression models to identify the risk factors for SARS-CoV-2 infections in the population. We retrieved the results of 219,729 SARS-CoV-2 tests, of which 7,333 were positive results. In the multivariable analysis, female sex was associated with a higher risk of testing positive for SARS-CoV-2 [odds ratio (OR) =1.30, 95% confidence interval (CI): 1.24-1.37, P