Valuing improvement in value-based purchasing

Medicare will soon implement hospital value-based purchasing (VBP) using a scoring system that rewards both achievement (absolute performance) and improvement (performance increase over time). However, improvement is defined so as to give less credit to initial low performers than initial high performers. Because initial low performers are disproportionately hospitals in socioeconomically disadvantaged areas, these institutions stand to lose under Medicare's VBP proposal.

We developed an alternative improvement scale and applied it to hospital performance throughout the United States. By using 2005 to 2008 Medicare process measures for acute myocardial infarction (AMI) and heart failure (HF), we calculated hospital scores using Medicare's proposal and our alternative. Hospital performance scores were compared across 5 locational dimensions of socioeconomic disadvantage: poverty, unemployment, physician shortage, and high school and college graduation rates. Medicare's proposed scoring system yielded higher overall scores for the most locationally advantaged hospitals for 4 of 5 dimensions in AMI and 2 of 5 dimensions for HF. By using our alternative, differences in overall scores between hospitals in the most and least advantaged areas were attenuated, with locationally advantaged hospitals having higher overall scores for 3 of 5 dimensions for AMI and 1 of 5 dimensions for HF.

Using an alternative VBP formula that reflects the principle of "equal credit for equal improvement" resulted in a more equitable distribution of overall payment scores, which could allow hospitals in both socioeconomically advantaged and disadvantaged areas to succeed under VBP.