An Application of Outcomes Monitoring for Coronary Artery Bypass Surgery 2005–2008 at TPCH

Objective To describe monitoring of four years’ isolated coronary artery bypass surgery outcomes and complications at The Prince Charles Hospital, Brisbane, Australia. Methods Analysis of Cardiac Surgical Register database using tabulations, funnel plots and random-effects (Bayesian shrinkage) analysis for aggregated data. Combined CUSUM and cumulative observed minus expected (modified VLAD) charts and combined CUSUM and cumulative funnel plots used for individual observation sequential data and binomial control charts and generalised additive models (GAMs) for quarterly sequential data. Risk adjustment employed re-calibrated EuroSCORE. Results There were 2575 procedures with an unadjusted in-hospital mortality rate of 1.17%. Mean age was 65 years and 21% of patients were female; 43.6% were elective procedures. Median ventilation time was 10 hours and median length of stay in intensive care (ICU) was 23 hours. Return to theatre for bleeding occurred in 3% of cases. Return to theatre for surgical site infection occurred in 0.4% of cases; 4% were re-do procedures. Permanent stroke or neurological deficit occurred in 1%, perioperative myocardial infarction in 0.8%, arrest in 1.2%, renal failure in 1.6% and ICU return in 2.3% of cases. Conclusions Complication rates and mortality were comparable with similar units. Use of random-effects (Bayesian shrinkage) analysis for aggregated data is encouraged together with generalised additive models (GAMs) and combined CUSUM and cumulative observed minus expected (modified VLAD) charts for sequential data.