Utility of provider volume as an indicator of medical care quality and for policy decisions

Associations between hospital volume or physician caseload and patient outcome have been used to assess the performance of health care providers. Although most studies have focused on major surgical procedures, in-hospital or 30-day mortality from many nonsurgical conditions and procedures has also been examined. Although high volume may be a surrogate for the provider’s skill and experience, and better outcomes may attract greater volumes, aggregate data on provider volume show many outliers indicating that the outcome for some low-volume providers is better than that for high-volume providers. Mortality is only one measure of medical care quality. Although high volume may not always be indicative of favorable outcome, referral of patients from low-volume to high-volume providers has been recommended. It has also been suggested that patients choose health care providers on the basis of physician caseload. It is unclear how such recommendations could be implemented in practice; furthermore, they would deprive many patients from access to, as well as disrupt the provision of, adequate health care in many areas. An alternative to requiring patients to receive care from high-volume providers is to adopt other measures for improving outcomes, such as improving the quality of care provided by low-volume providers and attracting better providers to low-volume areas.