Reimbursement levels for medical care in large US hospitals are reduced by up to 2% if compliance with evidence-based clinical care standards falls below threshold levels. Does this result in improved care compared to control hospitals not exposed to the financial incentive? To find out, intervention hospitals were compared to control hospitals. The ‘value based purchasing’ schemes were not introduced in a prospective experiment, and the controls (small rural hospitals) are very different in nature to those larger hospitals to whom the incentive applies. To mitigate potential bias, difference-in-difference approaches were used; hospitals were matched for previous performance; and the usual statistical adjustments were made. Adherence to appropriate clinical processes was increasing among both control and intervention hospitals before the intervention was implemented. Rates of adherence did not differ between intervention and control hospitals post-intervention. The clinical indicators related to three tracer conditions frequently used in studies of adherence to clinical standards – pneumonia, heart attack or heart failure. Patient experience measures also did not differ over intervention and controls, and while mortality was improved for pneumonia, it did not do so for the other conditions. The effect on pneumonia deaths was regarded as a chance finding (alpha error), given the null result on mediating variables (i.e. clinical process variables). Arguably these results were null because the incentive was low (only 2% of total reimbursement) and distributed over a large number of outcomes. Alternatively, doctors are largely intrinsically motivated and do not need financial incentives to moderate their performance. We will pick up on this issue in our next News Blog.
— Richard Lilford, CLAHRC WM Director
- Ryan AM, Krinsky S, Maurer KA, Dimick JB. Changes in Hospital Quality Associated with Hospital Value-Based Purchasing. N Engl J Med. 2017; 376: 2358-66.