Each year in the United States, about 15.4 million people are treated for asthma, but the impact of the disease extends beyond medical care, absenteeism, and mortality. “People with severe asthma are often refractory to standard treatment and have poor symptom control, but little is known about the impact of asthma on health-related quality of life (HRQOL) or health preference values by disease severity,” explains Haesuk Park, PhD. “Healthcare professionals (HCPs) need information on how asthma symptoms or severity affect HRQOL, including physical and mental health, and it’s important to recognize risk factors that negatively influence HRQOL.”

The 12-item Short Form Health Survey (SF-12) Questionnaire can distinguish clinically important HRQOL differences between patients with well-controlled and not-well-controlled asthma. “In addition, the SF-6D from the SF-12—which assesses health utility weights—enhances the evidence of associations between asthma and HRQOL by translating health outcomes into a preference-based value for cost-effectiveness studies,” Dr. Park adds.

For a study published in the Journal of Asthma & Allergy, Dr. Park, Kathryn Blake, PharmD, and colleagues estimated the HRQOL and health utilities of adult patients with asthma by the severity of asthma using SF-12 and SF-6D. The investigators also sought to identify factors associated with low HRQOL and health utilities in patients with asthma using nationally representative data.


Asthma Severity Impacts HRQOL

“When compared with patients without asthma, those with asthma had a significantly decreased HRQOL for both the physical and mental component summaries of the SF-12,” says Dr. Park. “A higher deterioration in physical health than mental health was seen among individuals with asthma. This may be related to poor lung function and activity limitations due to asthma.”

The study also showed that the percentage of patients reporting low quality of life in overall health increased as the severity of asthma worsened (Figure). “Patients with moderate and severe asthma had significantly lower HRQOL and health utilities—especially for physical health—when compared with those with mild disease,” says Dr. Park. After controlling for covariates, no significant differences in mental health by asthma severity were observed.


Vigilance Required for At-Risk Patients

Importantly, several risk factors were associated with poor HRQOL among patients with asthma. “When patients were subdivided by physical and mental health, our results suggest that female sex, older age, and less education were associated with poor physical health,” Dr. Blake notes. Other risk factors linked to poor HRQOL were lower household income, public insurance, smoking, and number of comorbidities.

Dr. Blake says the identification of patient groups at risk for poor physical health is a novel and important finding, which “suggests that HCPs should ensure that these patients fully understand the purpose of prescribed medications and how to correctly use inhalers. Older women, for example, may also have other comorbidities, such as arthritis, that can make it difficult to use certain inhalers, which places them at risk for asthma exacerbations.”

Of note, nearly 20% of patients with asthma reported low quality of life in mental health. “While poor mental health may not indicate depression, some adults with asthma may be mildly, moderately, or severely depressed,” says Dr. Blake. “As such, HCPs should regularly screen patients with asthma for depression using the Patient Health Questionnaire-9 and inquire about anxiety. Clinicians should also ask patients about their family and caregiver support systems if an asthma exacerbation occurs.”


Directions for Future Research

The Focused Update to the Asthma Management Guidelines from NHLBI, published in December 2020, identified several areas of further research to improve asthma care. “These areas include adherence, biologics, biomarkers to predict treatment response, and engagement of community health workers in asthma management,” Dr. Blake says. “The guidelines now recommend single maintenance and reliever therapy with inhaled corticosteroid (ICS)–formoterol-containing inhalers in patients with moderate to severe asthma, but additional data are needed in mild and intermittent asthma. Also, ICS–albuterol combination inhalers are being developed and need to be compared with ICS–formoterol for persistent asthma to determine their effects on reducing exacerbation frequency.”