Study Adds Knowledge to Asthma Severity’s Effects on Health-Related Quality of Life

A cross-sectional analysis shared data that added needed context for how patients diagnosed with asthma generally experience worsening health-related quality of life (HRQOL) tied to the severity of their condition.

The negative health effects of asthma are treated in about 15.4 million Americans each year, costing billions of dollars in medical care, mortality, and absenteeism from school and work. The authors believe this is the first study with a nationally representative US sample to track HRQOL and the severity of asthma’s effects on health utilities (ie, health preference values).

The data drew from the Agency for Healthcare Research and Quality and the National Center for Health Statistics. The nationally representative Medical Expenditure Panel Survey (MEPS) database was used to sort respondents from 2010-2016 into the severity categories of mild, moderate, and severe.

Data was collected using the Short Form Health Survey (SF-12) questionnaire, which gathers responses to 12 items for a generic HRQOL measure which patients received 2 scores in: the mental component summary (MCS) and physical component summary (PCS), with a lower score equaling worse patient condition. The MCS measured domains such as vitality, mental health, and social functioning, while the PCS measured domains like body pain and physical functioning.

Patient data was generated from 10,222 individuals. Instances of mild, moderate, and severe asthma were 75.4%, 23.9%, and .08% of patients respectively.

From this basis, reports of subjective low quality of life in overall patient health became worse with rising severity, at 27.6% of mild, 32.3% of moderate, and 37.1% of severe asthma (P < .001). Physical limitations resulting from the patients’ conditions were at 66.1% of severe asthma cases versus 26.7% with mild (P < .001). Crucially, the authors noted that there was “no significant differences in MCS by the severity of asthma after controlling for covariates.”

Overall, the mean PCS score was more negative than MCS (43.2 vs 48.4) (P < .001), which the authors feel supports the prioritization of improving physical factors over mental when patients undergo asthma care. This was made especially imperative by the fact that the utility weight for severe asthma, determined through general HRQOL measures, was 0.659. For reference, this figure was comparable to patients suffering pneumococcal pneumonia or type 2 diabetes experiencing major deterioration in quality of life from stroke (0.621) or heart failure (0.677).

Additionally, a number of patient characteristics were found to correlate to a lower scoring physical component summary. In tandem with asthma severity, being female, a lower educational attainment level, older age, and the use of public insurance each had a significant statistical association with lower patient PCS.

The study had several limitations. There are different definitions of asthma severity, which could affect the calculation of HRQOL. Asthma control may also affect HRQOL, but this was not captured by measuring asthma severity. Since the study was cross-sectional by nature, it could not measure HRQOL changes over time.

With this in mind, the data nevertheless supported the authors’ observations that a more notable drop occurs in PCS than in MCS when measuring moderate and severe cases of asthma as opposed to mild.

These results may prove useful in adding to the relatively small body of information known about the relation between HRQOL and how the severity of asthma affects a patient’s preference values.

“These data suggest that the management of physical health of female, older aged, and low education patients with asthma should be focused on improving HRQOL,” the authors concluded.

Reference

Song HJ, Blake KV, Wilson DL, Winterstein AG, Park H. Health-related quality of life and health utilities of mild, moderate, and severe asthma: Evidence from the Medical Expenditure Panel Survey. J Asthma Allergy. Published online July 28, 2021. doi: 10.2147/JAA.S316278