OBJECTIVE: To assess the accuracy and variability of clinicians' estimates of pre-test probability for three common clinical scenarios. DESIGN: Postal questionnaire survey conducted between April and October 2001 eliciting pre-test probability estimates from scenarios for risk of ischaemic heart disease (IHD), deep vein thrombosis (DVT), and stroke. PARTICIPANTS AND SETTING: Physicians and general practitioners randomly drawn from College membership lists for New South Wales and north-west England. MAIN OUTCOME MEASURES: Agreement with the "correct" estimate (being within 10, 20, 30, or > 30 percentage points of the "correct" estimate derived from validated clinical-decision rules); variability in estimates (median and interquartile ranges of estimates); and association of demographic, practice, or educational factors with accuracy (using linear regression analysis). RESULTS: 819 doctors participated: 310 GPs and 288 physicians in Australia, and 106 GPs and 115 physicians in the UK. Accuracy varied from about 55% of respondents being within 20% of the "correct" risk estimate for the IHD and stroke scenarios to 6.7% for the DVT scenario. Although median estimates varied between the UK and Australian participants, both were similar in accuracy and showed a similarly wide spread of estimates. No demographic, practice, or educational variables substantially predicted accuracy. CONCLUSIONS: Experienced clinicians, in response to the same clinical scenarios, gave a wide range of estimates for pre-test probability. The development and dissemination of clinical decision rules is needed to support decision making by practising clinicians.
OBJECTIVE: To assess the accuracy and variability of clinicians' estimates of pre-test probability for three common clinical scenarios. DESIGN: Postal questionnaire survey conducted between April and October 2001 eliciting pre-test probability estimates from scenarios for risk of ischaemic heart disease (IHD), deep vein thrombosis (DVT), and stroke. PARTICIPANTS AND SETTING: Physicians and general practitioners randomly drawn from College membership lists for New South Wales and north-west England. MAIN OUTCOME MEASURES: Agreement with the "correct" estimate (being within 10, 20, 30, or > 30 percentage points of the "correct" estimate derived from validated clinical-decision rules); variability in estimates (median and interquartile ranges of estimates); and association of demographic, practice, or educational factors with accuracy (using linear regression analysis). RESULTS: 819 doctors participated: 310 GPs and 288 physicians in Australia, and 106 GPs and 115 physicians in the UK. Accuracy varied from about 55% of respondents being within 20% of the "correct" risk estimate for the IHD and stroke scenarios to 6.7% for the DVT scenario. Although median estimates varied between the UK and Australian participants, both were similar in accuracy and showed a similarly wide spread of estimates. No demographic, practice, or educational variables substantially predicted accuracy. CONCLUSIONS: Experienced clinicians, in response to the same clinical scenarios, gave a wide range of estimates for pre-test probability. The development and dissemination of clinical decision rules is needed to support decision making by practising clinicians.
Authors: Thomas Agoritsas; Delphine S Courvoisier; Christophe Combescure; Marie Deom; Thomas V Perneger Journal: J Gen Intern Med Date: 2010-11-04 Impact factor: 5.128