Agreement between oscillometry and spirometry outcomes
Bronchodilator induced FEV1% change and change in oscillometry outcomes were correlated (Figure 1), however these correlations were weak (R2 <0.16, data not shown).
Of the 85 preterm individuals identified with a BDR (using published cut-offs), 76 had acceptable spirometry and oscillometry. Of these individuals, only 19 (25%) showed an agreement between tests; 38 (50%) were identified by spirometry only and 19 (25%) by oscillometry only (Figure 2). In the preterm group, agreement between tests was poor (k= 0.26; 95% CI 0.18 to 0.40, p<0.001). Similarly, in the term group, the agreement was extremely poor, with no overlap between tests (k= -0.06; 95% CI -0.10 to -0.01, p=0.641).
Oscillometry identified an additional 7 preterm-born individuals with a BDR that could not otherwise complete acceptable spirometry. Conversely, spirometry identified 2 preterm individuals with a BDR and no acceptable oscillometry measures.