Written action plan use in inner-city children: is it independently associated with improved asthma outcomes?

BACKGROUND Guidelines from the National Asthma Education and Prevention Program stipulate that multicomponent self-management interventions for asthma should include a written action plan (WAP). However the specific, independent effect of WAPs in improving outcomes remains unclear. OBJECTIVE To measure the association between WAP use during the previous year and improved asthma outcomes. METHODS We conducted a longitudinal quasi-experimental study using data from the Healthy Homes II (HH-II) randomized controlled trial in Seattle, WA. Action plan use during the previous year was measured at exit of HH-II. A participant was a WAP user if he used his action plan every day, almost every day, or once per week, and non-user if he did not meet these criteria. Sensitivity analyses explored less stringent criteria for WAP user designation. Prespecified outcomes were baseline-to-exit changes in asthma control in the previous 2 weeks, Pediatric Asthma Caregiver Quality of Life Scale score, and urgent health services utilization. We used robust linear and logistic regression to compare outcomes across groups. RESULTS Two hundred fifty-one patients participated: 112 WAP users; 139 non-users. After adjustment, no significant differences in outcomes were observed between WAP users and non-users. Among a subgroup of participants with recent urgent health services utilization, WAP users had better asthma control than non-users. Changing WAP user criteria to include those who simply owned an action plan, irrespective of use, did not alter our results. CONCLUSION WAP use during the previous year was not associated with improved outcomes compared with non-use. Additional studies are needed to assess the long-term, independent benefit of this universally recommended intervention.