Pre-Existing Characteristics Associated with Covid-19 Illness Severity

Ebinger, J. E.; Achamallah, N.; Ji, H.; Claggett, B. L.; Sun, N.; Botting, P.; Nguyen, T.-T.; Luong, E.; Kim, E. H.; Park, E.; Liu, Y.; Rosenberry, R.; Matusov, Y.; Zhao, S.; Pedraza, I.; Zaman, T.; Thompson, M.; Raedschelders, K.; Berg, A. H.; Grein, J. D.; Noble, P. W.; Chugh, S. S.; Bairey Merz, C. N.; Marban, E.; Van Eyk, J. E.; Solomon, S. D.; Albert, C. M.; Chen, P.; Cheng, S.

Background. Certain individuals, when infected by SARS-CoV-2, tend to develop more severe forms of Covid-19 illness for reasons that remain unclear. Objective. To determine the demographic and pre-existing clinical characteristics associated with increased severity of Covid-19 infection. Design. Retrospective observational study. We curated data from the electronic health record, and used multivariable logistic regression to examine the association of pre-existing traits with a Covid-19 illness severity defined by level of required care: need for hospital admission, need for intensive care, and need for intubation. Setting. A large, multihospital healthcare system in Southern California. Participants. All patients with confirmed Covid-19 infection (N=442). Results. Of all patients studied, 48% required hospitalization, 17% required intensive care, and 12% required intubation. In multivariable-adjusted analyses, patients requiring a higher levels of care were more likely to be older (OR 1.5 per 10 years, P<0.001), male (OR 2.0, P=0.001), African American (OR 2.1, P=0.011), obese (OR 2.0, P=0.021), with diabetes mellitus (OR 1.8, P=0.037), and with a higher comorbidity index (OR 1.8 per SD, P<0.001). Several clinical associations were more pronounced in younger compared to older patients (Pinteraction<0.05). Of all hospitalized patients, males required higher levels of care (OR 2.5, P=0.003) irrespective of age, race, or morbidity profile. Conclusion. In our healthcare system, greater Covid-19 illness severity is seen in patients who are older, male, African American, obese, with diabetes, and with greater overall comorbidity burden. Certain comorbidities paradoxically augment risk to a greater extent in younger patients. In hospitalized patients, male sex is the main determinant of needing more intensive care. Further investigation is needed to understand the mechanisms underlying these findings.