Table 2. Difference-in-Differences Estimates for Drug Administrations, Drug Costs, and Overall Costs.
| Estimate | Cancer drug administrations | Cancer drug costs, $a,b | Overall cancer costs, $b,c | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Breast | Lung | Colon | Prostate | Breast | Lung | Colon | Prostate | Breast | Lung | Colon | Prostate | |
| Mean (SD), No. | 1.52 (1.79) | 2.18 (2.44) | 3.70 (4.16) | 1.20 (1.76) | 4131 (2996) | 5777 (4164) | 4667 (4105) | 3083 (5335) | 2411 (2424) | 3407 (3407) | 2708 (3288) | 2089 (4004) |
| Observations, No. | 11 869 | 11 135 | 8592 | 9045 | 8733 | 7887 | 6065 | 6111 | 11 869 | 11 135 | 8592 | 9045 |
| Difference, OCM × postperiod (95% CI)d | –0.10 (–0.29 to 0.09) | –0.12 (–0.39 to 0.15) | –0.08 (–0.55 to 0.38) | –0.29 (–0.47 to –0.11) | –134 (–531 to 263) | –558 (–1173 to 58) | –146 (–1015 to 722) | –706 (–1383 to –29) | –233 (–495 to 30) | –337 (–618 to –55) | –385 (–780 to 10) | –610 (–1095 to –125) |
| P value | .28 | .38 | .71 | .003 | .49 | .07 | .73 | .04 | .08 | .02 | .06 | .02 |
| Change, relative to mean, % | –6.6 | –5.4 | –2.3 | –24.0 | –3.2 | –9.7 | –3.1 | –22.9 | –9.7 | –9.9 | –14.2 | –29.2 |
Abbrevation: OCM, Oncology Care Model.
a
Drug costs are conditional upon a billed patient with a given physician in a given month.
b
Costs are in monthly mean terms.
c
Monthly Enhanced Oncology Services payments were backed out at a uniform $160-monthly amount. Actual Monthly Enhanced Oncology Services payments varied, with 86% being paid at $156.80 ($160 − 2% under sequestration).
d
Confidence intervals are calculated using SEs clustered on practice.