Defining the volume-quality debate: is it the surgeon, the center, or the training?

The quality movement in health care is ubiquitous in our society. The volume-quality debate is a central component of this that affects surgeons. In colorectal surgery and other fields, studies have demonstrated improved outcomes for patients having care provided at higher volume centers. What is unclear about this relationship however, is whether this improvement is related to the center, the surgeon, or the surgeon's training and experience. Some studies have tried to better examine this relationship and have suggested that limitations in administrative data may exaggerate the impact of a high-volume center. The use of crude mortality as the primary outcome instead of more specific outcomes such as cancer recurrence, inadequate risk data, and the failure to account for clustering of cases are other important limitations. Although higher volume likely equates to higher quality in some form, this may be more related to surgeon-specific factors rather than high-volume centers alone. The role of subspecialization, especially colorectal-trained surgeons with a high individual case volume may be the most important predictor of higher quality in colorectal surgery. This relationship may be especially important for the treatment of rectal cancer. The relationship of volume to outcomes is difficult to understand, and to appropriately answer these questions will require the collection and analysis of comprehensive, risk-adjusted data after adequate outcome measures are defined. This will only occur with significant institutional support, and a commitment to follow outcomes longitudinally and implement necessary changes to improve outcomes.