Diagnostic accuracy of clinical symptoms in obstructive airway diseases varied within different health care sectors

Objective: To determine the diagnostic accuracy and diagnostic patterns of clinical symptoms in patients suspected to suffer from obstructive airway diseases (OADs) within different health care sectors. Study Design and Setting: Ten general practices (219 patients), one practice of pneumologists (259 patients) and one specialist hospital (300 patients). Sensitivities, specificities, positive (LR+), and negative (LR-) likelihood ratios of clinical symptoms were compared with lung function testing. Results: Thirty-one percent had chronic obstructive pulmonary disease (COPD), 21% had asthma. Sensitivities increased and specificities decreased from outpatient to hospital setting. The multivariate model of adjusted likelihood ratios for COPD showed LR+ = 4.86 (95% confidence interval [CI] = 2.09-11.29) and LR- = 0.07 (95% CI = 0.01-0.43) of the combination "wheezing," "dyspnea when going upstairs," "smoking" in general practice. In hospital, the combination "dyspnea when going upstairs," "dyspnea during minimal exercise," and "smoking" showed LR+ = 3.34 (95% CI = 2.08-5.31) and LR- = 0.02 (95% CI = 0.01-0.12). The combination "no coughing," "dyspnea attacks," and "no smoking" showed LR+ = 4.08 (95% CI = 1.67-10.4) and LR- = 0.24 (95% CI = 0.12-0.58) for asthma in general practice. The combination "dyspnea attacks" and "no dyspnea when walking" showed LR+ = 6.48 (95% CI = 1.01-40.94) and LR- = 0.28 (95% CI = 0.11-0.75) for asthma in hospital. Conclusion: Clinical decision rules for OAD need to be derived from original studies in their respective settings or assessed on their transferability to other settings.