Feasibility of school-based spirometry screening for asthma

To determine the feasibility and value of spirometry in school-based asthma screening, spirometry testing was coupled with parent questionnaires in a school-based asthma screening project. Children in grades five to eight of the Catholic school system in Rochester, Minn., performed spirometry with coaching and data acquisition by nurses trained for this activity. Most students completed three tests. For each student, the best test was selected for interpretation. Tests were considered technically unacceptable for screening purposes if the FEV1 was less than 85% and the curve showed evidence of cough, delayed start, poor initial effort, incomplete effort, or non-reproducibility. Students with acceptable tests and FEV1 < 85% as predicted for age, race, and BMI were classified as appropriate for referral for further evaluation of potential asthma. A sensitivity analysis was conducted using different FEV1 thresholds for referral. Children (119, 17.6% of all) with known asthma based on parent-completed questionnaire were not considered for referral. Of the remaining 557 students screened, 535 had technically acceptable tests, and 498 had normal spirometry performance. Using a threshold for referral of FEV1 < 85%, 37 children were candidates for referral for further evaluation of potential asthma. Only four (11%) of these also had questionnaire responses that made them candidates for referral. School-based spirometry screening for asthma is technically feasible but there is little overlap between those who are referral candidates based on spirometry data and those who are referral candidates based on parent-reported symptoms on screening questionnaires. Without further study, spirometry cannot be recommended for school-based asthma screening.