[Sensitivity and specificity of multi-frequency oscillation methods, body plethysmography and spirometry in...

We compared specificity and sensitivity of the forced oscillation technique with the standard methods of body plethysmography and spirometry in children suffering from asthma (age 5-8 yrs). We investigated 60 healthy and 66 asthmatic children by forced oscillation, plethysmography and spirometry. Mean FEV1% pred was 99.7 and 82.4% in the healthy and asthmatic subjects, respectively, and mean SRaw was 0.68 and 1.18 kPa*s, respectively. Forced oscillation and plethysmography could be measured in all children, whereas 29% of the investigated children failed to perform valid spirometry. Discriminant analysis was used to compare the optimal classification which could be obtained from the measured data with the clinical one. Fixing specificity to 95%, we computed sensitivities of 66% (forced oscillation), 68% (body plethysmography), and 76% (spirometry). We conclude that the diagnostic value of the three methods in young children with asthma is similar. However, the value of spirometry is limited by cooperation in these young children.