The Diagnostic Efficacy of Impulse Oscillometry for Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Impulse oscillometry (IOS) represents a non-invasive technique for assessing respiratory impedance and offers good clinical utility. Our study sought to systematically examine the accuracy of IOS in diagnosing chronic obstructive pulmonary disease (COPD). Eight databases (PubMed, Embase, Cochrane Library, etc.) were searched. We pooled data on diagnostic performance (sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic score, diagnostic odds ratio, summary receiver operating characteristic curves, and area under the curves). Fifteen studies were included, involving 9,895 subjects. Resonant frequency (Fres) showed a pooled sensitivity and specificity of 0.78 (95% CI: 0.71–0.84) and 0.75 (95% CI: 0.66–0.82), respectively. Frequency dependence of respiratory system resistance (R5-R20) and total airway reactance at 5 Hz (X5) showed pooled sensitivities of 0.77 (0.69–0.84) and 0.77 (0.60–0.89), and pooled specificities of 0.75 (0.66–0.83) and 0.79 (0.67–0.87), respectively. Total impedance (Z5) and total resistance (R5) demonstrated similar sensitivities (0.75 for both), with specificities of 0.69 and 0.72, respectively. The area of reactance (AX) exhibited the highest specificity (0.85) but a relatively lower sensitivity (0.70). Multiple IOS parameters showed moderate diagnostic accuracy for COPD, but the pooled estimates exhibited substantial heterogeneity and should therefore be interpreted cautiously. This indicates the potential clinical value of IOS and supports its use as a beneficial supplementary tool to spirometry.