Aim: To determine whether a numerical ranking system can provide an equitable basis for prioritising patients awaiting coronary artery bypass grafting.
Methods: A review of the current coronary surgery waiting list was undertaken using a newly developed scoring system. The factors included in the score were age, symptoms, results of exercise testing, coronary anatomy, employment status and perceived surgical risk. This score was compared with a Canadian consensus system. Rankings were then compared with the clinical priorities given by clinicians when the patients were placed on the waiting list.
Results: There was excellent correlation between the two priority ranking systems using only those items included in the Canadian system (r = 0.9179). However, correlation between the Canadian system and the full Green Lane Hospital (GLH) scoring system was weaker (r = 0.6869). The Canadian system assigned higher surgical priorities than Auckland clinicians. Comparison between the GLH system and clinical priority gradings (O, urgent out of hospital), (A) and (B) showed considerable scatter. Waiting times for these three categories considered acceptable by the Canadian consensus group were two to six weeks for priority (O), six weeks to three months for priority (A) and three to six months for priority (B). The mean times on the waiting list for the 260 patients still awaiting surgery at GLH were two months for (O), 11 months for (A) and 22 months for (B).
Conclusions: The Canadian and expanded GLH ranking systems are no more than aids to establishing priorities. They cannot replace clinical judgement because the importance of individual scoring items is heavily influenced by the ranking of other items. Waiting times for surgery are now grossly excessive despite the use of criteria for entry to the waiting list which are very conservative by international standards. There is no equitable or clinically acceptable way to modify priorities to reduce waiting times, and institution of a booking system is impractical.