In a new paper published in JAMA Network Open, researchers used the United States Department of Veterans Affairs (VA) national healthcare system to determine prognostic risk factors for poor outcomes of patients with severe SARS-CoV-2 infection. The primary goal of this study was to characterize risk factors associated with hospitalization, mechanical ventilation, and mortality in patients with SARS-CoV-2 infection.
Over 10,000 veterans with covid-19 were included in this study. Although the majority of patients were male (91 percent), the patient population was uniquely diverse: 49.6 percent were White, 41.6 percent Black and 9.3 percent Hispanic. Patients admitted to VA hospitals with SARS-CoV-2 were more likely to have long hospital admissions, require mechanical ventilation and die during the hospital stay (10.8 vs 2.4 percent) compared to patients admitted for conditions other than SARS-CoV-2 (and who did not also have the infection in addition to another medical problem).
Similar to other studies covered by Brief19, patients who were elderly and with numerous comorbidities such as diabetes and hypertension were more likely to die from covid-19. Clinical features such as fever and acute kidney failure were also associated with fatal outcomes. Most interestingly, obesity, chronic lung disease, Black race, Hispanic ethnicity and hypertension were not associated with increases in mortality (as has been shown by previous studies) among patients admitted to the hospital.
There are some limitations of this study to keep in mind. As with most studies that look at prognostic factors of covid-19, this was a retrospective study of patients whose outcomes were known at the beginning of the study. But while many of the other studies we have covered have had relatively small numbers of patients, this one was unusual, given its large sample size of patients representing hospitals all over the United States. While the results alone do not prove that chronic lung disease, obesity and hypertension are not in fact important risk factors for poor outcomes in covid-19 patients, it does call into question the strength of these associations observed in smaller, single center studies.