Predictors of short-term clinical response to acute asthma care in adults

Objective. We assessed the effects of potential patient risk factors on short-term clinical response to acute asthma care among adults who often require emergency department (ED) visits and hospitalizations to manage their asthma. Design and setting. Prospective cohort study that included adult patients treated for acute asthma, which was conducted in a US public hospital ED between March 1997 and August 1999, with a 2- to 3-week follow-up. Study participants. Three hundred and nine patients completed the study. Main measures. We identified patient risk factors that predicted lower peak expiratory flow rate (PEFR) change over 2-3 weeks following acute asthma care. Potential risk factors were ozone exposure, indoor allergy and exposure, smoking, upper respiratory infection in the last month, lower asthma knowledge, and medication non-adherence. Results. Univariate analyses indicated that lower asthma knowledge significantly and positively correlated with lower PEFR change (r=0.15, P=0.01). Multivariate analysis that controlled for patient case-mix indicated that indoor allergy and exposure [b=32.76, 95% confidence interval (CI)=3.98-61.53, P=0.03] significantly predicted lower PEFR change. There was no change in the multivariate analysis when the absence of treatment with corticosteroids during the 2-3 weeks before follow-up was added as a potential patient risk factor. Conclusion. The study suggests that interventions are needed to target the patient risk factors, indoor allergen exposure, and poor asthma knowledge, to promote short-term clinical response to acute asthma care in adults, especially among economically disadvantaged inner-city residents.