WHY DOES THE VOLUME–OUTCOME RELATIONSHIP MATTER? WHO CARES AND HOW COULD IT BE USED?
To set the context for the discussion, Dr. John Eisenberg, in opening remarks to workshop participants, identified a diverse set of potential users of information on the volume–outcome relationship.
Health Insurance Purchasers and Health Plans
Health insurance purchasers could use findings from research on the volume–outcome relationship to stipulate “evidence-based referrals” in contracts with health plans. Such a program is being explored by the Leapfrog Group, a coalition of employers interested in improving the quality of care for employees. In addition, employers could make information about the relationship between volume and outcome directly available to employees (e.g., on a company intranet site) and encourage employees to choose hospitals and providers based on available evidence. Similarly, health plans could direct members to high-volume providers.
Information about the relationship between volume and outcome could be provided more broadly through public websites, via advocacy groups, or as part of widely distributed quality report cards. In New York State, for example, information on the volume of cardiovascular and other procedures performed by individual surgeons and by hospitals is available through the Center for Medical Consumers, a nonprofit advocacy organization (www.medicalconsumers.org).
Insurers must decide which new technologies or services to include in their benefit packages and, sometimes, the conditions under which these new service will be provided. For a new technology, insurers could offer interim service coverage until any volume–outcome relationship can be established. Once a relationship became apparent, coverage could be conditional on its provision in high-volume settings.
Hospital administrators could, based on a positive volume–outcome relationship, decide to credential providers according to their volume of procedures or number of hospital admissions. Staffing decisions could also be affected. For some services, patients might be triaged to specialty units within hospitals, in part to ensure that providers have a sufficient volume to maintain their skills. One of the tenets of disease management is that assigning patients to certain disease-specific programs or institutions will improve care. This is not entirely related to volume, but evidence of a volume –outcome relationship for certain services could foster the development of specialty services, concentrating patients into settings with high volume.
A few states have certificate of need (CON) legislation, a regulatory mechanism for review and approval of capital expenditures and service capacity expansions by health care facilities. In