Context The accuracy of the clinical examination in detecting obstructive airway
disease (OAD) is largely unknown because of a paucity of methodologically
Objective To determine the accuracy of patient history, wheezing, laryngeal height,
and laryngeal descent in the diagnosis of OAD.
Design Comparison study conducted from November 3, 1998, to December 4, 1998,
evaluating 4 clinical examination elements for diagnosis of OAD vs the gold
standard of forced expiratory volume in 1 second (FEV1) and FEV1–forced vital capacity (FVC) ratio less than the fifth percentile
(adjusted for patient height, age, and sex).
Setting Twenty-five sites, including primary care and referral practices, in
Participants A total of 309 consecutive patients were recruited (mean age, 56 years;
43% female), 76 (25%) with known chronic OAD, 114 (37%) with suspected chronic
OAD, and 119 (39%) with neither known nor suspected OAD.
Main Outcome Measures Sensitivity, specificity, and likelihood ratios (LRs) for each of the
4 elements of the clinical examination compared with the gold standard.
Results Mean FEV1 and FVC values were 2.1 L/s and 2.9 L; 52% had
an FEV1 and FEV1-FVC ratio less than the fifth percentile.
The LR for wheezing was 2.7 (95% confidence interval [CI], 1.7-4.2) and was
not statistically significant in the multivariate model. The LR for laryngeal
descent ranged from 0.9 (95% CI, 0.5-1.4) to 1.2 (95% CI, 0.4-3.4), depending
on the cut point chosen, and did not enter the multivariate model. Only 4
of the history or physical examination elements we tested were significantly
associated with the diagnosis of OAD on multivariate analysis: smoking for
more than 40 pack-years (LR, 8.3), self-reported history of chronic OAD (LR,
7.3), maximum laryngeal height of at least 4 cm (LR, 2.8), and age at least
45 years (LR, 1.3). Patients having all 4 findings had an LR of 220 (ruling
in OAD); those with none had an LR of 0.13 (ruling out OAD). The area under
the receiver operating characteristic curve for the model incorporating these
4 factors was 0.86.
Conclusions Further research is needed to validate our model, but in the meantime,
our data suggest that less emphasis should be placed on the presence of individual
symptoms or signs (such as wheezing or laryngeal descent) in the diagnosis