Diagnostic value of signs and symptoms – the CARE studies
Jon Deeks with Sharon Straus (Toronto), Finlay McAlister (Edmonton) and Siew Chan (Sydney)
Despite the central importance of the clinical examination in the care of patients, its elements have rarely been subjected to rigorous evaluation. In order to obtain data on the clinical value of signs and symptoms, a programme of multinational studies involving investigators at various levels (primary, secondary and tertiary care) has been instigated (the CARE programme). The studies have been facilitated by a using a web-based approach for clinical recruitment and data collection.
The first study in the series was published in 2001. A second study investigated the accuracy of history and selected elements of the physical examination in the diagnosis of chronic obstructive pulmonary disease (COPD). A similar approach was used, and 161 consecutive patients were recruited from 7 different centres. The likelihood ratios (LR) for the tested elements of the clinical examination (and their P values on chi squared testing) were: self-reported history of COPD, 5.6 (p<0.001); forced expiratory time >9 seconds, 6.7 (p<0.001); smoked >40 pack years, 3.3 (P=0.001); wheezing, 4.0 (p<0.001); male sex, 1.6 (p<0.001); and age >65 years, 1.6 (P=0.025). In multivariate analysis only three elements of the clinical examination were significantly associated with the diagnosis of COPD: adjusted likelihood ratios were 4.1 for self-reported history of COPD, 2.4 for wheezing, and 3.4 for forced expiratory time >9 seconds. Patients having all 3 of these findings have a likelihood ratio of 33 (ruling in COPD); those with none have a likelihood ratio of 0.18 (ruling out COPD).
Recently further studies have been completed in tertiary care populations and a screening population. An analysis is underway to combine the four datasets to investigate whether the degree to which the diagnostic value of different items of the history and examination depends on the population sampled.
Publication: 37
