What is a safe waiting time for coronary artery bypass surgery?

To determine the factors that influenced doctors' prioritization anddecisions on safe waiting time for coronary artery bypass surgery, 50'paper patients', based on a random sample of cases who actually hadsurgery, were assessed by 33 clinicians. We used linear regression modelsto reflect the impact of clinical and non-clinical 'cues' on safe waitingtime and priority decisions. The benefits of surgery tended to beover-estimated. For example, the average perceived gain in life expectancyfor patients with left main-stem disease was 6.74 years. However, modelsincorporating only the perceptions of benefit as independent variables(i.e. the anticipated symptom reduction, MI risk reduction and lifeexpectancy extension), had only modest explanatory power (mean R2 was 0.55for safe waiting time, and 0.56 for priority decisions). Models whichincorporated perceptions of benefit and the cases' clinical andnon-clinical characteristics had generally much higher explanatory power(mean R2, 0.83 and 0.86, respectively). Lifestyle and demographic variableshad much less impact on the doctors' judgements than the major clinicalcues of angina severity and left main-stem stenosis. Demographic andlifestyle cues had different impacts on safe waiting time and priority forabout 25% of doctors.