Examining asthma quality of care using a population-based approach

Abstract

Background: Asthma accounts for considerable burden on health care, but in most cases, asthma can be controlled. Quality-of-care indicators would aid in monitoring asthma management. We describe the quality of asthma care using a set of proposed quality indicators.

Methods: We performed a retrospective cross-sectional study using health databases in Saskatchewan, a Canadian province with a population of about 1 million people. We assessed 6 quality-of-care indicators among people with asthma: admission to hospital because of asthma; poor asthma control (high use of short-acting beta-agonists, admission to hospital because of asthma or death due to asthma); no inhaled corticosteroid use among patients with poor control; at least moderate inhaled corticosteroid use among patients with poor control; high inhaled corticosteroid use and use of another preventer medication among patients with poor control; and any main preventer use among patients with poor control. We calculated crude and adjusted rates with 95% confidence intervals. We tested for differences using the chi2 test for proportions and generalized linear modelling techniques.

Results: In 2002/03, there were 24 616 people aged 5-54 years with asthma in Saskatchewan, representing a prevalence of 3.8%. Poor symptom control was observed in 18% of patients with asthma. Among those with poor control, 37% were not dispensed any inhaled corticosteroids, and 40% received potentially inadequate doses. Among those with poor control who were dispensed high doses of inhaled corticosteroids, 26% also used another preventer medication. Hospital admissions because of asthma were highest among those aged 6-9 years and females aged 20-44 years. Males and those in adult age groups (predominantly 20-44 years) had worse quality of care for 4 indicators examined.

Interpretation: Suboptimal asthma management would be improved through increased use of inhaled corticosteroids and preventer medications, and reduced reliance on short-acting beta-agonist medications as recommended by consensus guidelines.

Figure 1: Prevalence of asthma in Saskatchewan by age and sex in 2002/03. *Significant difference (p < 0.05) between males and females.

Figure 2: Rates of hospital admission because of asthma among people with asthma in Saskatchewan in 2003/04. *Significant difference (p < 0.05) between males and females.

Figure 3: Rates of asthma quality-of-care indicators in Saskatchewan in 2003/04. All rates, except crude overall rates, were adjusted using the indicator denominator population (Table 1). Residents with registered Indian status were excluded from our study. Of the cases identified in 2002/03 (26 616), 24 180 were eligible for inclusion in 2003/04. *Adjusted for sex. †Adjusted for age. ‡Adjusted for age and sex. §Significantly different (p < 0.05) from the rate across all other categories within the variable group. ¶At least moderate inhaled corticosteroid use was defined as ≥ 251 μg/d for fluticasone and beclomethasone-HFA, ≥ 501 μg/d for beclomethasone-CFC and budesonide nebulizer solution, ≥ 1001 μg/d for beclomethasone dry powder inhaler, ≥ 401 μg/d for budesonide inhaler. Note: CI = confidence interval, NR = not reported (owing to a sample size of less than 6).