Asthma screening as part of a routine school health assessment in the Australian Capital Territory

OBJECTIVE: To determine the feasibility and performance of a routine screen for childhood asthma in new entrants to primary school relative to diagnosis by a paediatrician. DESIGN: Cross-sectional study with a validation substudy. PARTICIPANTS AND SETTING: All 4539 new primary school entrants (mean age, 5.72 years; 95% CI, 5.71-5.74) in the Australian Capital Territory (ACT) in 1999; 180 of these children (73% of the 248 contacted) participated in the validation substudy. MAIN OUTCOME MEASURE: Performance of the screening test relative to a paediatrician's diagnosis of current asthma (defined as a history of wheeze suggestive of a clinical diagnosis of asthma within the past 12 months) based on history and examination. RESULTS: 3748 of the 4539 new primary school entrants (83%) returned completed asthma and respiratory questions. The screening test was positive in 38% of children. Estimated sensitivity was 92% (95% CI, 75%-99%); specificity, 76% (95% CI, 72%-80%); positive predictive value, 51% (95% CI, 41%-63%); negative predictive value, 98% (95% CI, 90%-100%); positive likelihood ratio, 3.8 (95% CI, 2.8-4.8); and negative likelihood ratio, 0.14 (95% CI, 0.02-0.33). CONCLUSIONS: It is feasible to conduct population screens for asthma that have good diagnostic test performance against a specialist paediatrician's diagnosis through school health programs. This approach could facilitate monitoring changes in asthma prevalence over time.