Abstract
Wilson et al state that cardiovascular surgery programs should "adhere to standard morbidity and mortality criteria rather than case-volume criteria." We agree, as long as criteria are defined a priori (with appropriate recognition of the need to adjust for factors such as a hospital's case mix) and "adherence" is defined as statistically acceptable evidence that an individual surgery unit has met these criteria. The burden of proof needs to be shifted to hospitals to show that they are providing high-quality services.Unfortunately, definitive statistical evidence is rarely available for an individual surgery unit.1 Our data suggest that, given a lack of other evidence, patients might improve their chances of a good outcome if, after consultation with their physician, they choose to have surgery in a high-volume surgery unit.