Background: Evidence-based medicine is gaining prominence in primary care. This study sought to examine the relationships among family physicians' attitudes toward EBM, contextual factors, and clinical decision-making and to investigate the factors that contribute to 'contrary to evidence' clinical decisions.
Methods: A postal survey mailed to a random sample of Canadian family physicians, stratified by age, gender, and practice setting. The main outcome measures were respondents' attitudes toward evidence-based medicine and preferred treatment option in four simulated clinical scenarios with wording randomly varied.
Results: Canadian family physicians report positive attitudes toward EBM, believe that EBM improves patient care, and agree that research findings are useful in the day-to-day management of patients. The scenario study showed that physicians were strongly influenced by a patient demanding/requesting either a screening test (adjusted Odds Ratio [OR] 5.15, 95% confidence interval [CI] 2.9 to 9.2 for demand mammogram; adjusted OR 3.11, 95% CI 1.7 to 5.6 for request mammogram) or a diagnostic test (adjusted OR 3.95, 95% CI 2.1 to 7.5 for demand lumbar spine x-ray; adjusted OR 2.08, 95% CI 1.1 to 4.1 for request x-ray). This relationship did not hold for the treatment scenario (prescribing antibiotics for acute bronchitis) where hours of practice (adjusted OR 3.5, 95% CI 1.1 to 11.7 for 50+ hours practice; adjusted OR 1.79, 95% CI 1.0 to 3.2 for 20-49 hours practice) and type of practice (adjusted OR 2.22, 95% CI 1.3 to 3.7 for solo practice) were significant. 80% of respondents reported teaching breast self-examination with female physicians twice as likely as males (adjusted OR 2.11, 95% CI 1.2 to 3.8).
Conclusions: Canadian family physicians are favourably disposed to the precepts of evidence-based medicine; however, patient expectations and practice characteristics can influence physicians such that decisions are taken that are broadly contrary to evidence. Recently revised models of EBM emphasizing the importance of patient preferences and the clinical context appear to reflect more accurately the clinical reality of primary care physicians.