Validation of the auscultatory method for diagnosing peripheral arterial disease.

BACKGROUND: The Ankle brachial index (ABI) has been shown to be useful in diagnosing peripheral arterial disease (PAD). Ankle systolic blood pressures are measured by a Doppler device; however, general physicians cannot always use it in daily practice. The ausculutatory method (AUS) is an alternative method and quite easy to perform, but has not yet been validated in diagnosing PAD. OBJECTIVE: To validate AUS for diagnosing PAD based on ABI, compared with Doppler method as gold standard. METHODS: Cross-sectional study. Study subjects were 119 patients aged 50 years and older, who were consecutively admitted to the division of general internal medicine in two community hospitals in Japan. We measured the systolic blood pressures of the brachial and the posterior tibial arteries by two methods. We calculated the ABI from the systolic blood pressure obtained by these two methods. PAD was considered to be present when ABI 0.9. CONCLUSIONS: While AUS is not efficient enough to confirm the presence of PAD based on ABI, it could be clinically useful in excluding PAD when ABI >0.90. When measuring ankle blood pressure by AUS in the daily practice, it is important to realise its strengths and weaknesses.

Interpretation of and preference for probability expressions among Japanese patients and physicians.

BACKGROUND: Patients and physicians often communicate using qualitative probability expressions that describe expected outcomes or risks of a medical intervention without knowing whether or not they share the same understanding. OBJECTIVE: The aim of the present study was to determine interpretations of qualitative probability expressions in clinical settings by Japanese patients and physicians as well as their assessments and preferences about physicians' use of such expressions. METHODS: One hundred and sixty-eight consecutive patients aged 16 years or older, who attended a university hospital during a 2-week period in 1999, and 156 physicians recruited through the Japanese General Medicine Research Network participated in this cross-sectional survey, using a self-administered questionnaire. Participants were asked to assign numerical interpretations as a percentage to 10 qualitative expressions of probability in two clinical situations related to prescribing a medicine for a cold and an anti-cancer drug. They were also asked which type of expression, qualitative or quantitative, they usually use when communicating probabilistic clinical information and which they prefer. RESULTS: The estimates of probability expressions showed wide variations, especially among patients. Patients tended to assign lower and higher values to highly positive and negative probability expressions, respectively, than physicians. Clinical context also influenced the estimation: both groups tended to assign higher estimates in the anti-cancer drug situation than in the cold treatment situation. Factor analysis revealed three psychologically meaningful factors in each situation. More patients than physicians (64.6% versus 50.3%) thought that physicians do not use numbers in routine practice. More than 20% of both patients and physicians considered that the actual use of qualitative terms by physicians is undesirable. Nevertheless, a sizable number of patients (41.4%) and physicians (15.2%) considered it preferable that physicians do not use numbers. CONCLUSION: Since interpretation of qualitative expressions of probability in Japanese is subject to large interpersonal variability and differences between patients and physicians, as well as context dependence, the use of qualitative expressions alone might cause misunderstanding among the parties involved. However, the majority of patients prefer words to numbers at present. Therefore, physicians, at least in Japan, ought to provide patients with both numbers and words when critical decisions need to be communicated.