Random clinical decisions: identifying variation in perioperative care.

T HE phrase “cleared for surgery” is one that nearly every anesthesiologist has seen documented in the medical record of a patient presenting for surgery. Unfortunately, being “cleared for surgery” means very little to the scrutinizing anesthesiologist. More fundamentally, it is unclear why certain patients are referred to be “cleared” in the first place. In this issue of ANESTHESIOLOGY, Wijeysundera et al. explore the practice of preoperative medical consultation and shed light on this intriguing part of the perioperative process. Using administrative data from 79 hospitals and more than 200,000 patients undergoing elective surgery in Ontario, Canada, over 5 yr, they observed that more than one-third of patients were referred for preoperative medical consultation. This preoperative medical consultation visit was distinct from routine primary care and presumably hoped to achieve the theoretical goals of preoperative optimization: reducing day of surgery delays or cancellations, day of surgery urgent testing, and ensuring that medical management of chronic comorbid diseases was consistent with contemporary guidelines and perioperative needs. However, the authors observed a striking range of consultation rates across hospitals, from 10 to 897 consultations per 1,000 patients. Of greater interest, although patients undergoing consultation were older and sicker, patient or procedural factors only explained 5.9% of the observed variation in consultation rates across hospitals. Essentially, the consultation process is driven by hospital practice patterns, provider preferences, and other unmeasured factors rather than patient risk and procedural complexity. Quantifying the extent of adjusted variation is the first step in a journey of quality improvement. At its most extreme, unexplained variation is attributable to either the absence of evidence-basedguidelines to establish standards of care or the absence of evidencebased care despite accepted standards of care. In reality, a blend between the two extremes is usually the cause of variation in care. Nearly every clinical specialty has described significant variation in care, from percutaneous coronary intervention in acute myocardial infarction to radioactive iodine for thyroid cancer. As a result, what is striking about the data presented by Wijesundera et al. is not the presence of variation, but the fact that it has taken so long for a robust analysis of multicenter data to be reported. Although the field of anesthesiology has been hailed as a patient safety leader for its reduction of catastrophic intraoperative mishaps, our specialty must now expand its quality-improvement efforts beyond rare events. A beginning point is to assess the extent of variation in fundamental processes of care controlled by the anesthesiologist, such as anesthesia technique, use of peripheral nerve blockade, invasive monitoring, blood pressure management strategies, and intraoperative medications. Although sporadic data evaluating the variation in use of general anesthesia for ophthalmic, orthopedic, and obstetric procedures have been published, our field