Accountable care organizations (ACOs) that have a high proportion of minority patients were associated with low scores on about three-fourths of Medicare quality performance measures, according to new research published in Health Affairs.
Researchers from Dartmouth Institute, UC-Berkeley and elsewhere, set out to analyze racial and ethnic disparities in healthcare outcomes among ACOs to investigate the association between the share of an ACO’s patients who are members of racial or ethnic minority groups and the ACO’s performance on quality measures.
Using data from Medicare and a national survey of ACOs, they found that having a higher proportion of minority patients was associated with worse scores on 25 of 33 (76 percent) of Medicare quality performance measures, two disease composite measures, and an overall quality composite measure.
However, ACOs serving a high share of minority patients were similar to other ACOs in most observable characteristics and capabilities, including provider composition, services, and clinical capabilities. The findings suggested that ACOs with a high share of minority patients may struggle with quality performance under ACO contracts, especially during their early years of participation—maintaining or potentially exacerbating current inequities, according to the researchers.
Researchers conducted cross-sectional and longitudinal analyses of the quality performance of ACOs participating in the federal Medicare Shared Savings Program (MSSP) during the first and second years of their contracts, paying specific attention to the proportion of each ACO’s minority patients. In total, the research is based on data from the first contract year for 306 Medicare ACOs and from the second performance year for 191 ACOs (with data available, and substantive results on the associations of interest were the same as in the analysis of data from the first year). They then compared ACOs with a high proportion of minority patients to other ACOs on characteristics and capabilities from the National Survey of ACOs (there were 214 ACOs for which both CMS and survey data were available).
The mean percentage of minority patients attributed to ACOs was 17.8 percent; each ACO in the top 5 percent of ACOs in terms of proportion of minority patients had a patient population with more than 50 percent minority patients. The results indicated that ACOs serving a high proportion of minority patients had patients who were higher risk, somewhat sicker or more costly, and perhaps disadvantaged in other ways (for example, on Medicaid), compared to other ACOs.
What’s more, the proportion of minority patients was associated with worse performance on 29 of 36 measures unadjusted for patient and ACO characteristics, and on 25 of 36 adjusted for those characteristics. In some cases (such as patient’s rating of the doctor and influenza immunization), the associations between quality performance and proportion of minority patients decreased in magnitude and significance after adjustment. In other cases (such as shared decision making, screening for fall risk, and adult weight screening and follow-up), the associations increased in magnitude. But overall, these results suggest that some, but certainly not all, of the association between quality and the proportion of minority patients can be explained by a patient population with overall higher risk or higher acuity. In other words, some of the association of quality with minority patient share can be explained by the fact that ACOs with more minority patients also have, on average, sicker patients, the researchers stated.
Also notably, the association of proportion of minority patients and quality performance existed across all four domains of quality scores. The association was strongest in the domains of preventive health and at-risk populations, where more measures were associated with the proportion of minority patients. In addition, providers with high proportions of minority patients had lower overall quality composite scores, compared to other providers. This measure is used by CMS to determine the share of generated savings that an ACO will receive.
The researchers also tested whether ACOs with a high proportion of minority patients improved their performance more rapidly, compared to other ACOs. They found that in general, disparities in quality performance between ACOs with a high proportion of minority patients and other ACOs did not narrow between the first and second performance years.
They further noted that the difference in performance occurred across many types of measures, including both clinical and process measures. They wrote that while clinicians may have more control over process measures than over clinical measures, the results show that even on process measures, providers with a high proportion of minority patients often performed worse than other providers.
The researchers suggested that policy makers might want to consider using additional risk adjustment for quality outcomes to take into account socioeconomic characteristics of patients, such as race or income. This adjustment could make comparisons of provider quality fairer by taking into account patient-level factors beyond a provider’s control, such as patients’ financial resources, they said.
They concluded, “These results may have troubling implications. ACO programs are voluntary: Providers that participate in the Medicare Shared Savings Program have made a deliberate decision to do so. Providers may decide not to participate in programs such as ACOs if they are concerned about their ability to meet performance metrics. Our results indicate that a substantial share of providers may be either not capable or not ready to participate successfully in these programs. As Medicare aims to move an increasing share of healthcare providers to alternative payment models, the uneven mix and diversity of providers participating in ACO programs could have implications for patient-level disparities, outcomes, and care.”
