E C ardiac surgery is truly a team effort, dependent for its success on the knowledge, skills, and behaviors of a team of health professionals, supporting staff, and community caregivers. 1 Hitherto, attention has typically focused on the performance of the cardiac surgeon with little consideration of the contribution to outcomes of other members of the team, notably the anesthesiologist. 2 In this edition of the journal, Glance et al. 3 report on a retrospective study of 7920 patients undergoing coronary artery bypass graft in which the rate of death or major complications varied markedly across anesthesiologists. Analyses were controlled for patient demographics, severity of coronary artery disease, comorbidities, and hospital quality. It was assumed that assignment to surgeon was random. The rate of death or serious complications in patients managed by low-performing anesthesiologists (3.33%; 95% confidence interval, 3.09-3.58) was nearly double the rate in patients managed by high-performing anesthesiologists (1.82%; 95% confidence interval, 1.58%-2.10%). Results were similar for all patient risk groups.In this editorial, we consider 3 questions: How reliable is this observation? If this observation is true, what is the reason? If this observation is true, what should be done about it?
HOW RELIABLE IS THIS OBSERVATION?This study has many strengths. The large patient cohort, derived from a population of approximately 20 million in New York state, underwent surgery during a short time span, so changes over time in the practice or performance of individual anesthesiologists were minimized. The analyses were adjusted for factors outside the control of anesthesiologists that may have affected the outcome, such as patient health status, and the observed effect was large, clinically relevant, and consistent with previous findings. 4,5 This study also has limitations, many of which were enumerated by Glance et al. 3 in their article. Three limitations concern us. First, data on the training, qualifications, and years of experience of the anesthesiologists are not collected in the New York State Cardiac Reporting System and therefore were not included in the analyses. We think these factors matter in cardiac anesthesiology. 6 Second, the volume of practice of the included anesthesiologists was not considered. Anesthesiologists who managed <50 cases during the study period were excluded because of concerns about the precision of adjusted outcomes for low-volume providers. This amounted to 66% of the anesthesiologists and 33% of the cases. However, anesthesiologists managing widely varying numbers of patients remained in the cohort and their volumes of practice could have been factored in. It is known that volume of practice matters for cardiac surgeons, so why not cardiac anesthesiologists? 2 Third, Glance et al. assumed that assignment of anesthesiologists to cases was random with respect to surgeon. They justified this on the grounds that they needed to choose between hospital and surgeon as a fixed effect in their ...
