Association of Medicare Advantage Star Ratings With Racial, Ethnic, and Socioeconomic Disparities in Quality of Care

Abstract

Importance: Medicare Advantage (MA) plans, which disproportionately enroll racial/ethnic minorities and persons with socioeconomic disadvantage, receive bonus payments on the basis of overall performance on a 5-star rating scale. The association between plans' overall quality and disparities in quality is not well understood.

Objective: To examine the association between MA star ratings and disparities in care for racial/ethnic minorities and enrollees with lower income and educational attainment.

Design setting and participants: This cross-sectional study included 1 578 564 MA enrollees from 454 contracts across the 2015 and 2016 calendar years. Data analyses were conducted between June 2019 and June 2020.

Exposures: Self-reported race and ethnicity and low socioeconomic status (SES) (defined by low income or less than a high school education) vs high SES (neither low income nor low educational attainment).

Main outcomes and measures: Performance on 22 measures of quality and satisfaction determined at the individual enrollee level, aggregated into simulated star ratings (scale, 2-5) stratified by SES and race/ethnicity.

Results: A total of 1 578 564 enrollees were included in this analysis (55.8% female; mean [SD] age, 71.4 [11.3] years; 65.8% White; 12.3% Black; 14.6% Hispanic). Enrollees with low SES had simulated stratified star ratings 0.5 stars lower (95% CI, 0.4-0.6 stars) than individuals with high SES in the same contract. Black and Hispanic enrollees had simulated star ratings that were 0.3 stars (95% CI, 0.2-0.4 stars) and 0.1 stars (95% CI, -0.04 to 0.2 stars) lower than White enrollees within the same contracts. Black enrollees had a 0.4-star lower rating (95% CI, 0.1-0.7 stars) in 4.5- to 5-star contracts and a no statistical difference in 2.0- to 2.5-star-rated contracts (difference, 0.3 stars; 95% CI, -0.02 to 0.7 stars). Hispanic enrollees had a 0.6-star lower simulated rating (95% CI, 0.2-1.0 stars) in 4.5- to 5-star contracts and no statistical difference in 2- to 2.5-star contracts (difference, -0.01 stars; 95% CI, -0.5 to 0.4 stars). There was low correlation between simulated ratings for enrollees of low SES and high SES (difference, 0.2 stars; 95% CI, 0.03-0.4 stars) and between simulated ratings for White and Black enrollees (difference, 0.4 stars; 95% CI, 0.3-0.5 stars) and White and Hispanic enrollees (difference, 0.3 stars; 95% CI, 0.2-0.4 stars). As the proportion of Black and Hispanic enrollees increased in a contract, racial/ethnic disparities in ratings decreased.

Conclusions and relevance: In this cross-sectional study, simulated MA star ratings were only weakly correlated with those for enrollees of low SES in the same contract, and contracts with higher star ratings had larger disparities in quality. Measures of equity in MA plans' quality of care may be needed.

Figure 1.. Association Between Simulated Star Ratings for Enrollees with High vs Low Socioeconomic Status (SES) and for White vs Racial/Ethnic Minority Enrollees in the Same Medicare Advantage Contract

Each point represents a contract and plots the calculated star rating for each group. Dots above the 45-degree line indicate that either the high SES or the White enrollee stratified star ratings are higher than that of the comparison group. The US Centers for Medicare & Medicaid Services rounds star ratings to the nearest 0.5 increment. Dark blue dots represent that after rounding the star rating for each group would be the same. Orange dots represent that after rounding the stratified star ratings would be different.

Figure 2.. Socioeconomic and Racial/Ethnic Disparity in Simulated Star Rating by Decile of Low Socioeconomic Status (SES) or Race/Ethnicity Within the Medicare Advantage Contract

Each point represents the disparity in star rating between each group (low SES and high SES or Black or Hispanic and White) by decile of SES or race/ethnicity concentration. Points above the 0 line indicate that the enrollees with low SES or Black or Hispanic enrollees in a contract perform worse in star-rating calculations than the comparison groups. If the 95% CIs do not cross the line at 0, then there is a statistically significant disparity at the .05 level. The cut points for each decile are included in eTable 2 in the Supplement.

Figure 3.. Socioeconomic and Racial/Ethnic Disparity in Simulated Star Ratings by US Centers for Medicare & Medicaid Services’ Published Contract-level Star Rating

The y-axis in each panel represents either the average difference in stratified star rating between enrollees with low socioeconomic status (SES) and high SES or between White enrollees and Black or Hispanic enrollees. The x-axis represents the contract’s official star rating from 2016. Points above the 0 line indicate that the contracts perform worse for enrollees with low SES or Black and Hispanic enrollees. If the 95% CIs do not cross the line at 0, then there is a statistically significant disparity at the .05 level. For enrollees with low SES, the 4-star and 4.5- to 5-star–level disparities are significantly higher than the 2.5-star and 3-star groups (P < .05). For Black enrollees, the 4-star and 4.5- to 5-star–level disparities are significantly higher than the 3-star group (P < .05). For Hispanic enrollees, the 4-star and 4.5- to 5-star–level disparities are significantly higher than the 2.5-star and 3-star groups (P < .05).