To avoid severe COVID-19 outcomes, people with asthma should stay on top of the condition with control medication during the pandemic

Individuals with well-controlled asthma have less severe COVID-19 outcomes than those with uncontrolled asthma, according to a large study conducted by USC and Kaiser Permanente Southern California.

The findings, published today in The Journal of Allergy and Clinical Immunology: In Practice suggest that asthma patients, especially those who require clinical care, should continue taking control medications during the COVID-19 pandemic.

“Anyone with asthma should continue to work with their healthcare provider to ensure they are getting the best treatment for their asthma, which leads to better asthma control and decreases the likelihood of severe COVID-19 outcomes,” said co-first author Zhanghua Chen, an assistant professor of population and public health sciences at the Keck School of Medicine of USC.

Approximately 25 million Americans have asthma, a potentially serious underlying condition in the face of widespread COVID transmission. The asthma numbers equal about 1 in 13 Americans, including 8 percent of adults and 7 percent of children.

The USC/Kaiser collaboration gave researchers a chance to evaluate the impact of breathing disorders on COVID outcomes in a population with equal access to health care.

Researchers collected data on 61,338 COVID-19 patients using electronic medical records from Kaiser Permanente Southern California from March 1 to August 31, 2020. The mean age was 43.9; 53.9% were women and 66% had Hispanic race/ethnicity.   

Medical codes were used to determine if these patients had asthma or chronic obstructive pulmonary disease (COPD) prior to their COVID-19 diagnosis. Researchers also separated the data further, with the “active” group accounting for any patients who’d had a clinical visit for asthma within the last 12 months, and the “inactive” group accounting for those who had not.

A total of 2,751 patients were in the inactive asthma group versus 2,775 in the active asthma group. Additionally, 820 patients had a history of COPD. Patients in the active asthma group had significantly higher odds of hospitalization, a need for intensive respiratory support (IRS), and ICU admission within 30 days of COVID-19 diagnosis compared to those with inactive asthma, or no history of asthma or COPD.

A history of COPD was associated with a higher risk of hospitalization, need for intensive respiratory support, and death within 60 days from COVID-19. Notably, researchers did not see a higher likelihood of mortality within 60 days for the active asthma group. 

“This study went beyond examining asthma’s impact on COVID-19 outcomes, and instead focused on how COVID-19 outcomes might change for asthma patients depending on their level of asthma control,” said study author Anny H. Xiang, PhD, of the Kaiser Permanente Southern California Department of Research & Evaluation. “We also saw that even in patients with active asthma, if they were using asthma medications their odds of worsened COVID-19 outcomes decreased, which demonstrates just how important these medications are.”

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In addition to Chen and Xiang, other study authors are co-first author Brian Huang of the Keck School and Kaiser; Sandrah Eckel, Duncan Thomas and Frank Gilliland, all of the Keck School; Margo Sidell and Mayra Martinez of Kaiser; and Fred Lurmann of Sonoma Technology.

This study was supported by the National Institute of Environmental Health Sciences (grant No. 3R01ES029963-01), and the National Cancer Institute (grant Nos. T32CA229110 and K99CA256525) at the National Institutes of Health, and the COVID-19 Pandemic Research Center (CPRC) at the Keck School of Medicine of USC’s Department of Population and Public Health Sciences.