WHAT IS A SAFE WAITING TIME FOR CORONARY-ARTERY BYPASS-SURGERY

To determine the factors that influenced doctors' prioritization and d ecisions on safe waiting time for coronary artery bypass surgery, 50 ' paper patients', based on a random sample of cases who actually had su rgery, were assessed by 33 clinicians. We used linear regression model s to reflect the impact of clinical and non-clinical 'cues' on safe wa iting time and priority decisions. The benefits of surgery tended to b e over-estimated. For example, the average perceived gain in life expe ctancy for patients with left main-stem disease was 6.74 years. Howeve r, models incorporating only the perceptions of benefit as independent variables (i.e. the anticipated symptom reduction, MI risk reduction and life expectancy extension), had only modest explanatory power (mea n R-2 was 0.55 for safe waiting time, and 0.56 for priority decisions) . Models which incorporated perceptions of benefit and the cases' clin ical and non-clinical characteristics had generally much higher explan atory power (mean R-2, 0.83 and 0.86, respectively). Lifestyle and dem ographic variables had much less impact on the doctors' judgements tha n the major clinical cues of angina severity and left main-stem stenos is. Demographic and lifestyle cues had different impacts on safe waiti ng time and priority for about 25% of doctors.