Comparison of home-based spirometry and oscillometry measurements in school-age children with bronchopulmonary dysplasia

Introduction: This study compares home-based oscillometry and spirometry for characterizing respiratory system disease in school-aged children with bronchopulmonary dysplasia (BPD) in clinical research. We hypothesized higher rates of successful completion and abnormal cases identified through oscillometry, with correlations between device measurements.

Methods: Participants 6-12 years old with BPD in the ongoing Air Quality, Environment and Respiratory Outcomes in BPD (AERO-BPD) study performed oscillometry followed by spirometry at two separate home visits. Parameters measured included airway resistance at 5 Hz(R₅), resistance from 5 to 19 Hz(R_5-19), resonance frequency(F_res), reactance at 5 Hz(X₅), area under the curve between F_res and X₅(AX), forced expiratory volume in 1 second(FEV₁), forced vital capacity(FVC), and FEV₁/FVC. Descriptive statistics identified the proportion of successful tests, correlation in measurements, and rate of lung disease for each device.

Results: Among 76 subjects with 120 paired observations, 95% and 71% of participants successfully performed oscillometry and spirometry, respectively, at home visit one. 98% and 77% successfully performed oscillometry and spirometry, respectively, at home visit two. Odds ratios favored oscillometry (range 5.31-10.13, p < 0.01). FEV₁ correlated with AX (correlation coefficient r = -0.27, p = 0.03); FEV₁/FVC with AX (r = -0.32, p = 0.02); and FEV₁/FVC with R₅ (r = -0.37, p = 0.01). AX exhibited the highest prevalence of abnormality at 25%; other oscillometry parameters ranged from 5%-22%. Forty-five to sixty-four percent of participants had abnormal spirometry. Oscillometry assessments had significantly lower odds of capturing lung disease (odds ratios 0.07-0.24, p < 0.0001).

Conclusions: School-aged children with BPD demonstrated higher success rates in field-based oscillometry than spirometry. Spirometry exhibited higher rates of abnormality than oscillometry. Moderate correlation exists between device measurements.