Factors including older age and certain comorbidities have been linked to more serious COVID-19 outcomes in previous research, and now a large dataset collected from hundreds of hospitals nationwide provides more detailed data regarding risk for mechanical ventilation and death.
History of pulmonary disease or smoking, interestingly, were not.
One expert urges caution when interpreting the results, however. Although the study found a number of risk factors for ventilation and mortality, she says the dataset lacks information on race and disease severity, and the sample may not be nationally representative.
The investigators hope their level of granularity will further assist researchers searching for effective treatments and clinicians seeking to triage patients during the COVID-19 pandemic.
The study was published online August 28 in Clinical Infectious Diseases.
COVID-19 and comorbidities
“What I found most illuminating was this whole concept of comorbid conditions. This provides suggestive data about who we need to worry about most and who we may need to worry about less,” study author Robert S. Brown Jr, MD, MPH, told Medscape Medical News.
Comorbid conditions included hypertension in 47% of patients, diabetes in 28%, and cardiovascular disease in 19%. Another 16% were obese and 12% had chronic kidney disease. People with comorbid obesity, chronic kidney disease, and cardiovascular disease were more likely to receive mechanical ventilation compared to those without a history of these conditions in an adjusted, multivariable logistic analysis.
With the exception of obesity, the same factors were associated with risk for death during hospitalization.
In contrast, hypertension, history of smoking, and history of pulmonary disease were associated with a lower risk of needing mechanical ventilation and/or lower risk for mortality.
Furthermore, people with liver disease, gastrointestinal diseases, and even autoimmune diseases – which are likely associated with immunosuppression – “are not at that much of an increased risk that we noticed it in our data,” Brown said.
“As I tell many of my patients who have mild liver disease, for example, I would rather have mild liver disease and be on immunosuppressant therapy than be an older, obese male,” he added.
Assessing data for people in 38 U.S. states, and not limiting outcomes to patients in a particular COVID-19 hot spot, was a unique aspect of the research, said Brown, clinical chief of the Division of Gastroenterology and Hepatology at Weill Cornell Medicine in New York City.
Brown, lead author Michael W. Fried, MD, from TARGET PharmaSolutions in Durham, North Carolina, and colleagues studied adults from a commercially available Target Real-World Evidence (RWE) dataset of nearly 70,000 patients. They examined hospital chargemaster data and ICD-10 codes for COVID-19 inpatients between February 15 and April 20.
This population tended to be older, with 60% older than 60 years. A little more than half of participants, 53%, were men.
Key findings
A total of 21% of patients died after a median hospital length of stay of 8 days.
Older patients were significantly more likely to die, particularly those older than 60 years (P < .0001).
“This confirms some of the things we know about age and its impact on outcome,” Brown said.
The risk for mortality among patients older than 60 years was 7.2 times that of patients between 18 and 40 years in an adjusted multivariate analysis. The risk for death for those between 41 and 60 years of age was lower (odds ratio [OR], 2.6), compared with the youngest cohort.
Men were more likely to die than women (OR, 1.5).
When asked if he was surprised by the high mortality rates, Brown said, “Having worked here in New York? No, I was not.”