Comparing Clinical Characteristics of Influenza and Common Coronavirus Infections Using Electronic Health Records

Abstract Background We compared outcomes in inpatients and outpatients, pre-COVID-19, who were infected with either coronavirus or influenza. Methods Using deidentified electronic health records data from the Geisinger-Regeneron partnership, we compared patients with RT-PCR–positive tests for the 4 common coronaviruses (229E, HKU1, NL63, OC43) or influenza (A and B) from June 2016 to February 2019. Results Overall, 52 833 patients were tested for coronaviruses and influenza. For patients ≥21 years old, 1555 and 3991 patient encounters had confirmed positive coronavirus and influenza tests, respectively. Both groups had similar intensive care unit (ICU) admission rates (7.2% vs 6.1%, P = .12), although patients with coronavirus had significantly more pneumonia (15% vs 7.4%, P < .001) and higher death rate within 30 days (4.9% vs 3.0%, P < .001). After controlling for other covariates, coronavirus infection still had a higher risk of death and pneumonia than influenza (odds ratio, 1.64 and 2.05, P < .001), with no significant difference in ICU admission rates. Conclusions Common coronaviruses cause significant morbidity, with potentially worse outcomes than influenza. Identifying a subset of patients who are more susceptible to poor outcomes from common coronavirus infections may help plan clinical interventions in patients with suspected infections. While common coronavirus infections are thought to be generally mild compared to influenza, this study showed increased risk of both death within 30 days of diagnosis and pneumonia for patients with RT-PCR–confirmed infections.