Longitudinal Validation of a Tool for Asthma Self-Monitoring

Abstract

WHAT'S KNOWN ON THIS SUBJECT: To prevent asthma exacerbations, asthma guidelines recommend ongoing monitoring of patients' asthma symptoms to promote timely adjustments of therapy to achieve and maintain optimal control. Existing tools, validated for ongoing monitoring, have significant limitations in children.WHAT THIS STUDY ADDS: Our study established longitudinal validation of the Asthma Symptom Tracker, a novel tool designed for use by children or their parents to facilitate ongoing monitoring of patients' asthma symptoms and proactive medical decision-making to prevent acute exacerbations. abstract OBJECTIVES: To establish longitudinal validation of a new tool, the Asthma Symptom Tracker (AST). AST combines weekly use of the Asthma Control Test with a color-coded graph for visual trending.METHODS: Prospective cohort study of children age 2 to 18 years admitted for asthma. Parents or children (n = 210) completed baseline AST assessments during hospitalization, then over 6 months after discharge. Concurrent with the first 5 AST assessments, the Asthma Control Questionnaire (ACQ) was administered for comparison.RESULTS: Test-retest reliability (intraclass correlation) was moderate, with a small longitudinal variation of AST measurements within subjects during follow-ups. Internal consistency was strong at baseline (Cronbach' s a 0.70) and during follow-ups (Cronbach' s a 0.82-0.90). Criterion validity demonstrated a significant correlation between AST and ACQ scores at baseline (r = 20.80, P , .01) and during follow-ups (r = 20.64, 20.72, 20.63, and 20.69). The AST was responsive to change over time; an increased ACQ score by 1 point was associated with a decreased AST score by 2.65 points (P , .01) at baseline and 3.11 points (P , .01) during follow-ups. Discriminant validity demonstrated a strong association between decreased AST scores and increased oral corticosteroid use (odds ratio 1.13, 95% confidence interval, 1.10-1.16, P , .01) and increased unscheduled acute asthma visits (odds ratio 1.23, 95% confidence interval, 1.18-1.28, P , .01). CONCLUSIONS:The AST is reliable, valid, and responsive to change over time, and can facilitate ongoing monitoring of asthma control and proactive medical decision-making in children. Pediatrics 2013;132:e1554-e1561 AUTHORS: