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Oxford University Press - PMC COVID-19 Collection logoLink to Oxford University Press - PMC COVID-19 Collection
. 2020 Oct 27:ciaa1624. doi: 10.1093/cid/ciaa1624

Risk Factors for testing positive for SARS-CoV-2 in a national US healthcare system

Vincent S Fan 1,, Jason A Dominitz 2, McKenna C Eastment 3, Emily Locke 4, Pamela Green 4, Kristin Berry 4, Ann M O’Hare 5, Javeed A Shah 3, Kristina Crothers 1, George N Ioannou 2
PMCID: PMC7665412  PMID: 33105485

Abstract

Background

Identifying risk factors for SARS-CoV-2 infection could help health systems improve testing and screening strategies.

Objectives

Identify demographic factors, comorbid conditions, and symptoms independently associated with testing positive for SARS-CoV-2.

Design

Observational cross-sectional study.

Setting

Veterans Health Administration.

Patients

Persons tested for SARS-CoV-2 nucleic acid by polymerase chain reaction (PCR) between March 1 and May 14, 2020.

Measurements

Associations between demographic characteristics, diagnosed comorbid conditions, and documented symptoms with testing positive for SARS-CoV-2.

Results

Of 88,747 persons tested, 10,131 (11.4%) were SARS-CoV-2 PCR positive. Positivity was associated with older age (≥80 vs. <50 years: aOR 2.16, 95% CI 1.97-2.37), male sex (aOR 1.45, 95% CI 1.34-1.57), regional SARS-CoV-2 burden (≥2,000 vs. <400 cases/million: aOR 5.43, 95% CI 4.97-5.93), urban residence (aOR 1.78, 95% CI 1.70-1.87), Black (aOR 2.15, 95% CI 2.05-2.26) or American Indian/Alaska Native/Pacific Islander (aOR 1.26, 95% CI 1.05-1.52) vs. White race, and Hispanic ethnicity (aOR 1.52, 95% CI 1.40-1.65). Obesity and diabetes were the only two medical conditions associated with testing positive. Documented fevers, chills, cough, and diarrhea were also associated with testing positive. The population attributable fraction of positive tests was highest for regional SARS-CoV-2 burden (35.3%), followed by demographic variables (27.2%), symptoms (12.0%), obesity (10.5%), and diabetes (0.4%).

Limitations

Lack of information on SARS-CoV-2 exposures or the indications for testing which may affect the likelihood of testing positive.

Conclusion

The majority of positive SARS-CoV-2 tests were attributed to regional SARS-CoV-2 burden, demographic characteristics and obesity with a minor contribution of chronic comorbid conditions.


Articles from Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America are provided here courtesy of Oxford University Press

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