• Health policy
• Health professions education
• Health services research

Healthcare organisations have a mandate to provide the highest standard of care for patients and their families. While it may be difficult to empirically demonstrate that an organisation provides a high standard of care using basic outcomes such as mortality,1 the foundations of both measuring and improving healthcare quality include consideration of adequate structures and processes of care with proven relationships to better outcomes.2 ,3 Healthcare organisations rely on evidence-based processes of care (eg, proven medication for the treatment of acute myocardial infarction and appropriate prevention strategies for avoiding postoperative infections, such as the use of deep venous thrombosis prophylaxis in hospitalised patients) and structures (such as adequate nurse–patient ratios and sufficient patient volumes for complex surgical procedures) to support quality for several important reasons.4 First, outcomes are influenced by patient-level factors that are unrelated to quality of care, such as case-mix5; second, risk-adjustment models are unreliable in detecting true outliers, with a large degree of variation across different models of care6 and third, even with perfect risk adjustment unmeasured confounders, such as differences in the proportions of high-risk patients, can produce misleading measures of performance.7 ,8 And, finally, organisations frequently do not have enough volume of cases to distinguish high performers from low performers within a useful time frame.9 Thus, it is imperative to identify structures and processes of care that are associated with better outcomes.

Processes of care are frequently identified from randomised controlled trials. Once a new drug or intervention is shown to be superior to a control (either a placebo …