Key Point:

Poor health-related quality of life independently predicts the need for ED asthma treatment; adherence to asthma treatment guidelines improves patients’ quality of life.

NEW YORK CITY—Health-related quality of life (QOL) and effective asthma treatment are clearly related, but does proper disease management improve quality of life in asthma patients, or does a poor quality of life make disease management harder? Both sides of this question were examined by investigators in the United States and the Netherlands. The two groups found, respectively, that poor quality of life is predictive of subsequent asthma-related emergency department (ED) visits and that better asthma care improves quality of life.[1,2]

The US study sought to identify risk factors for ED use among 1,406 asthma patients belonging to a large health plan. The Dutch investigators compared health-related quality of life in 146 asthma patients whose treatment did—or did not—meet international guidelines for care.

PHYSICAL SYMPTOMS, QOL, AND ED USE

In the US study, the asthma patients completed questionnaires about their physical health and quality of life. In addition, a subgroup of 360 patients underwent spirometry within three months of when the surveys were completed. The health plan’s database revealed that 116 of the 1,406 patients required asthma-related ED treatment during the one-year follow-up.

Physical functioning was below normal in more than half of the patients in the study. In fact, the mean Physical Component Summary score (which indicates physical health status) was 0.6 standard deviations lower in the study population than in the general population.

When the asthma patients were stratified by their Physical Component Summary scores, those with lower totals had worse baseline health status and were more likely to have an asthma-related ED visit than those with higher scores. A 10-point decrement in Physical Component Summary score was associated with a 72% increased risk of ED use.

Similarly, the patients with low scores on the Asthma Quality of Life Questionnaire were more likely to have subsequent asthma-related ED visits. Each 1-point decrement in Asthma Quality of Life score was associated with a 34% increased risk of ED use.

The association between ED use and poor health status or quality of life could not be explained simply by disease severity—at least among the subset of patients who underwent spirometry. After the investigators controlled their analysis for FEV1, both physical functioning and health-related quality of life remained independent predictors of ED use.

The investigators acknowledged that they do not know which quality-of-life factors affected the need for ED treatment or whether improvement in health-related quality of life could reduce ED visits for asthma. They suggest that patients with poor health-related quality of life may need more intensive medical evaluation or therapy. These patients may also benefit from specialist care or a disease management program.

COMPLIANCE WITH CARE AFFECTS QOL

In the Dutch investigation, researchers studied how patient adherence to the NIH international asthma guidelines affects health-related quality of life. The study included 146 adult asthma patients who were registered with a large general practice database. Participants had FEV1 measured and were given a questionnaire regarding asthma symptoms, medication use, and asthma-related quality of life.

Each patient’s treatment regimen was classified as adherent or nonadherent to the NIH Expert Panel Report 2 Guidelines for the Diagnosis and Management of Asthma. Disease severity was determined using the NIH guideline for pharmacological management of asthma, which combines asthma symptoms with lung function data. Severity was rated from class 1 to 4, with class 4 being the most severe. Health-related quality of life was assessed with a questionnaire.

USING ADEQUATE TREATMENT IMPROVES QOL

Slightly more than half of the treatment regimens were considered nonadherent. Furthermore, the likelihood that management did not conform to recommendations rose as disease severity increased. Treatment regimens were nonadherent in 16 (31%) of the 51 patients in class 1, five (56%) of the nine patients in class 2, 40 (57%) of the 70 patients in class 3, and 13 (81%) of the 16 patients in class 4.

In all four classes, the most commonly encountered problems were that patients were given no short-acting ß-agonist for symptomatic relief or that they were given only a short-acting ß-agonist. For example, four of the five class 2 patients with nonadherent regimens were using only a short-acting ß-agonist; they had not received an anti-inflammatory agent. Of the 40 class 3 patients with nonadherent treatment, 18 had not been given a short-acting ß-agonist and 27 were not using an anti-inflammatory medication. Of the 13 nonadherent class 4 patients, 10 were not using a short-acting ß-agonist, three did not have any anti-inflammatory medication, and six had not received either a long-acting ß-agonist or ipratropium.

Health-related quality of life decreased as asthma severity increased, falling from a mean of 6.1 in class 1 patients to 4.8 in class 4 patients. Patients treated according to the NIH guidelines had a significantly higher health-related quality of life than did those who were nonadherent (5.7 vs 5.3, respectively).

—Gale Jurasek