With decreasing health care reimbursements, increasing costs, and payments more frequently linked to quality and safety outcomes, health care systems struggle with determining which services are sustainable and how to consistently deliver high quality care safely and affordably.
Embedded in this discussion and analysis is the question of whether there is a relationship between the volume in a particular service line and the outcomes of that service line. From a business perspective, there is a relationship between volume and cost; fixed expenses spread over a larger volume reduce unit cost. As long as variable expenses do not overshadow fixed expenses, providing more units of service, appropriate for the patients, reduces the cost of that service.
What do we know about the relationship of volume to outcomes? It’s very difficult to generalize because most studies involve surgical procedures. Comprehensive reviews
suggest there is a difference in quality and safety between high-volume providers and hospitals, and low-volume providers and hospitals. While it may seem intuitive that “practice makes perfect,” it seems that this is not always true. With all we know about the importance of reliable systems, there is also a relationship between high-volume providers working in high-volume hospitals that seem synergistic. It is likely that high volume hospitals have more reliable systems to ensure the process of care.
For example, one study of volume and myocardial infarction mortality showed better mortality in high-volume institutions that was highly correlated with better use of aspirin and beta blocker protocols. The data also suggest that the difference between high-volume and low-volume providers and hospitals is especially important with new technologies. Interestingly, intermediate-volume providers can look like high-volume providers or low-volume providers. A systematic review in 2002
concluded “high-volume is associated with better outcomes across a wide range of procedures and conditions, but the magnitude of the association varies greatly.” The authors note that differences in processes and case mix influence the association.
Implementation of volume standards (not performing these procedures unless volume minimums are met) for 5 high risk procedures is estimated to save 2,500 lives a year. (Surgery 2001; 130:415-22).
How are providers and health care administrators going to use volume in making difficult decisions about service line sustainability in the context of needing to achieve the triple aim? There is no one answer, so I suggest that it has to be an important factor because it does seem to significantly impact outcomes and cost. It would not be fair or rational to use volume as the only factor. If volume is low, administrators and providers will need to assure themselves that such services are affordable and of high quality.
As physicians and other providers are more carefully evaluated for their outcomes, it seems reasonable to use volume as an indicator to take a more careful look, but if outcomes, cost, and patient experience are all high, then sustainability becomes the question. How much training, support services, and process standardization is needed to sustain such services?
In health care, our current ability to perform true cost accounting is dismal. So when we calculate costs, we miss hidden labor costs and other costs required to sustain the infrastructure for low-volume services. And in the context of effective health care policy, providers need to take a broad view of alternative service providers and their volumes, outcomes, patient experience, and cost. If it’s difficult and expensive to maintain a service locally, and there is a good service nearby, is it the best use of resources to sustain a low-volume service?
There is a complex relationship between volume and outcomes, which means volume is best used as a trigger to carefully evaluate quality, safety, cost, sustainability, and alternatives. How would you approach this complicated issue?