Diagnosis-wide analysis of COVID-19 complications: an exposure-crossover study

CMAJ. 2021 Jan 4;193(1):E10-E18. doi: 10.1503/cmaj.201686. Epub 2020 Dec 7.

Abstract

Background: Many studies reporting coronavirus disease 2019 (COVID-19) complications have involved case series or small cohorts that could not establish a causal association with COVID-19 or provide risk estimates in different care settings. We sought to study all possible complications of COVID-19 to confirm previously reported complications and to identify potential complications not yet known.

Methods: Using United States health claims data, we compared the frequency of all International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) diagnosis codes occurring before and after the onset of the COVID-19 pandemic in an exposure-crossover design. We included patients who received a diagnosis of COVID-19 between Mar. 1, 2020, and Apr. 30, 2020, and computed risk estimates and odds ratios (ORs) of association with COVID-19 for every ICD-10-CM diagnosis code.

Results: Among 70 288 patients with COVID-19, 69 of 1724 analyzed ICD-10-CM diagnosis codes were significantly associated with COVID-19. Disorders showing both strong association with COVID-19 and high absolute risk included viral pneumonia (OR 177.63, 95% confidence interval [CI] 147.19-214.37, absolute risk 27.6%), respiratory failure (OR 11.36, 95% CI 10.74-12.02, absolute risk 22.6%), acute kidney failure (OR 3.50, 95% CI 3.34-3.68, absolute risk 11.8%) and sepsis (OR 4.23, 95% CI 4.01-4.46, absolute risk 10.4%). Disorders showing strong associations with COVID-19 but low absolute risk included myocarditis (OR 8.17, 95% CI 3.58-18.62, absolute risk 0.1%), disseminated intravascular coagulation (OR 11.83, 95% CI 5.26-26.62, absolute risk 0.1%) and pneumothorax (OR 3.38, 95% CI 2.68-4.26, absolute risk 0.4%).

Interpretation: We confirmed and provided risk estimates for numerous complications of COVID-19. These results may guide prognosis, treatment decisions and patient counselling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • COVID-19 / complications*
  • COVID-19 / diagnosis
  • COVID-19 / epidemiology
  • COVID-19 Testing / methods*
  • Cross-Over Studies
  • Female
  • Humans
  • Incidence
  • Male
  • Pandemics*
  • Pneumonia, Viral / diagnosis*
  • Pneumonia, Viral / epidemiology
  • Pneumonia, Viral / etiology
  • Risk Assessment / methods*
  • SARS-CoV-2*
  • United States / epidemiology