Table 2.
Rates of and changes in utilization of total knee and hip replacements after health reform in Massachusetts (MA) by race/ethnicity and socioeconomic status
| Population | Procedure rate (/10 000) (95% CI) | Overall change (%)* | % Change associated with health reform† | ||
|---|---|---|---|---|---|
| Before reform | After reform | Mean (95% CI) | P value‡ | ||
| Total knee and hip replacements | |||||
| All | 29.0 (28.5 to 29.4) | 35.5 (35.0 to 36.0) | 22.4 | 4.7 (2.3 to 7.1) | <0.001 |
| Race/ethnicity: | |||||
| White, non-Hispanic | 30.1 (29.6 to 30.6) | 37.3 (36.7 to 37.8) | 23.9 | 2.8 (1.3 to 4.4) | 0.03 |
| Black, non-Hispanic | 28.1 (26.0 to 30.2) | 37.9 (35.7 to 40.1) | 34.9 | 11.4 (7.2 to 15.8) | 0.03 |
| Hispanic | 12.9 (11.4 to 14.5) | 17.9 (16.4 to 19.4) | 38.8 | 37.9 (31.8 to 44.2) | <0.001 |
| Zip code median income: | |||||
| Low | 25.5 (24.6 to 26.4) | 33.3 (32.3 to 34.2) | 30.6 | 7.7 (1.9 to 13.8) | <0.001 |
| Medium | 28.9 (28.0 to 29.8) | 35.1 (34.1 to 36.0) | 21.5 | 3.7 (−0.2 to 7.7) | 0.12 |
| High | 30.4 (29.8 to 31.1) | 36.5 (35.9 to 37.2) | 20.1 | 4.7 (3.0 to 6.4) | <0.001 |
| Total knee replacements | |||||
| All | 17.5 (17.2 to 17.9) | 21.8 (21.4 to 22.2) | 24.6 | 5.3 (2.5 to 8.6) | <0.001 |
| Race/ethnicity: | |||||
| White, non-Hispanic | 18.0 (17.6 to 18.4) | 22.5 (22.1 to 22.9) | 25.0 | 3.5 (0.3 to 6.7) | 0.03 |
| Black, non-Hispanic | 18.5 (16.8 to 20.2) | 26.1 (24.3 to 28.0) | 41.1 | 18.7 (12.4 to 25.5) | 0.01 |
| Hispanic | 9.9 (8.6 to 11.3) | 13.6 (12.3 to 15.0) | 37.4 | 33.0 (32.0 to 34.1) | <0.001 |
| Zip code median income: | |||||
| Low | 16.7 (16.0 to 17.4) | 21.5 (20.7 to 22.3) | 28.7 | 6.3 (−0.2 to 12.4) | 0.06 |
| Medium | 17.7 (17.0 to 18.4) | 22.3 (21.6 to 23.1) | 26.0 | 6.5 (3.7 to 9.4) | 0.03 |
| High | 17.7 (17.2 to 18.2) | 21.6 (21.1 to 22.1) | 22.0 | 5.4 (2.7 to 8.1) | 0.01 |
| Total hip replacements | |||||
| All | 11.5 (11.2 to 11.8) | 13.7 (13.4 to 14.0) | 19.1 | 3.9 (0.1 to 7.8) | 0.05 |
| Race/ethnicity: | |||||
| White, non-Hispanic | 12.1 (11.8 to 12.5) | 14.8 (14.4 to 15.1) | 22.3 | 2.1 (−1.4 to 5.8) | 0.28 |
| Black, non-Hispanic | 9.6 (8.4 to 10.8) | 11.8 (10.6 to 13.0) | 22.9 | −1.8 (−7.1 to 3.8) | 0.84 |
| Hispanic | 3.0 (2.3 to 3.7) | 4.2 (3.5 to 5.0) | 40.0 | 49.8 (26.7 to 77.1) | 0.01 |
| Zip code median income: | |||||
| Low | 8.8 (8.3 to 9.4) | 11.7 (11.1 to 12.3) | 33.0 | 10.6 (4.9 to 16.5) | 0.02 |
| Medium | 11.2 (10.6 to 11.8) | 12.7 (12.2 to 13.3) | 13.4 | −0.3 (−6.5 to 6.4) | 0.94 |
| High | 12.7 (12.3 to 13.1) | 14.9 (14.5 to 15.4) | 17.3 | 4.2 (−2.8 to 11.7) | 0.10 |
*Overall change is % change between procedure rates before and after reform.
†Change associated with MA health reform obtained from difference-in-differences Poisson regression model to adjust for difference secular changes (based on comparison with New Jersey, New York, and Pennsylvania) with fixed effects for quarter and state. Standard errors corrected for clustering within states.
‡P value associated with null hypothesis of no change in procedure use associated with reform.