Comparison of Characteristics Between Accountable Care Organizations Serving the Least to Most Deprived Communities in 2014
| Quartile 1 (Least Deprived Service Area), Mean (SD) | Quartile 2, Mean (SD) | Quartile 3, Mean (SD) | Quartile 4 (Most Deprived Service Area), Mean (SD) | Diff. (Q1–Q4), P Value | |
|---|---|---|---|---|---|
| Savings rate (%) | 1.14 (4.65) | −0.18 (4.46) | −0.25 (5.42) | 1.19 (4.95) | |
| Shared in savings | 0.31 (0.47) | 0.23 (0.42) | 0.25 (0.44) | 0.23 (0.42) | |
| Organization characteristics | |||||
| Number of assigned beneficiaries | 22,245 (19518) | 18,552 (17667) | 14,864 (10962) | 9,714 (6782) | <.01 |
| Entry year | |||||
| 2012 | 0.36 (0.48) | 0.25 (0.44) | 0.39 (0.49) | 0.34 (0.48) | |
| 2013 | 0.31 (0.47) | 0.36 (0.48) | 0.3 (0.46) | 0.24 (0.43) | |
| 2014 | 0.33 (0.47) | 0.39 (0.49) | 0.31 (0.47) | 0.43 (0.5) | |
| Region | |||||
| Northeast | 0.34 (0.48) | 0.19 (0.39) | 0.15 (0.36) | 0.15 (0.36) | <.01 |
| Midwest | 0.23 (0.42) | 0.23 (0.42) | 0.28 (0.45) | 0.10 (0.3) | <.05 |
| South | 0.33 (0.47) | 0.4 (0.49) | 0.44 (0.5) | 0.58 (0.5) | <.01 |
| West | 0.11 (0.32) | 0.19 (0.39) | 0.14 (0.35) | 0.18 (0.38) | |
| Track 2 | 0.00 (0.00) | 0.00 (0.00) | 0.01 (0.11) | 0.03 (0.16) | |
| Per capita historical benchmark ($) | 10,172 (2090) | 9,613 (1801) | 10,741 (2314) | 11,284 (3145) | <.01 |
| Quartile 1 | 0.25 (0.44) | 0.36 (0.48) | 0.18 (0.38) | 0.21 (0.41) | |
| Quartile 2 | 0.24 (0.43) | 0.30 (0.46) | 0.26 (0.44) | 0.20 (0.40) | |
| Quartile 3 | 0.33 (0.47) | 0.21 (0.41) | 0.26 (0.44) | 0.20 (0.40) | <.1 |
| Quartile 4 | 0.19 (0.39) | 0.13 (0.33) | 0.30 (0.46) | 0.39 (0.49) | <.01 |
| % Primary care physicians | 42.26 (21.14) | 41.95 (20.32) | 40.57 (18.12) | 44.55 (21.1) | |
| Beneficiary characteristics | |||||
| % Age 85 and older | 13.1 (3.0) | 12.5 (3.2) | 12.6 (3.1) | 11.5 (4.1) | <.01 |
| % Female | 57.5 (2.0) | 57.1 (2.0) | 57.6 (1.8) | 57.6 (2.6) | |
| % Aged duals | 4.0 (2.8) | 5.0 (4.0) | 6.3 (3.3) | 16.4 (15.2) | <.01 |
| % White | 88.3 (8.2) | 88.9 (6.8) | 83.8 (11.1) | 67.8 (21.6) | <.01 |
| % Disabled | 10.4 (3.7) | 13.0 (5.3) | 15.6 (4.4) | 20.4 (10.6) | <.01 |
| HCC score | 1.0 (0.1) | 1.0 (0.1) | 1.1 (0.1) | 1.1 (0.1) | <.05 |
| Service area characteristics | |||||
| Number of ZCTAs | 32.2 (19.4) | 32.7 (22.6) | 27.4 (24.3) | 33.9 (29.7) | |
| Social Deprivation index | −0.70 (0.21) | −0.26 (0.09) | 0.04 (0.08) | 0.53 (0.33) | <.01 |
| % < 12 years of schooling | 8.5 (1.9) | 10.9 (1.9) | 13.6 (2.1) | 19.5 (6.6) | <.01 |
| % Crowded housing units | 1.7 (0.8) | 2.1 (1.1) | 2.4 (1.3) | 4.9 (3.5) | <.01 |
| % Households with no care | 5.9 (1.9) | 6.4 (1.9) | 8.0 (2.9) | 12.9 (12.9) | <.01 |
| % < 100% FPL | 8.7 (2.4) | 12.5 (2.0) | 14.6 (2.1) | 19.9 (5.6) | <.01 |
| % Renter occupied | 26.0 (5.2) | 31.3 (5.0) | 33.2 (5.0) | 39.9 (10.5) | <.01 |
| % Single-parent households | 13.9 (2.7) | 16.6 (2.0) | 18.8 (2.3) | 21.4 (4.4) | <.01 |
| N | 80 | 80 | 80 | 80 |
FPL, federal poverty level; HCC, Hierarchical Condition Category; SD, standard deviation; ZCTA, ZIP code tabulation area.
Sources: Accountable Care Organizations (ACOs) were identified using the 2014 Shared Savings Program (SSP) ACO Provider File. Their beneficiaries were identified using the 2014 SSP Beneficiary File. The beneficiary ZIP codes were from the 2014 Master Beneficiary Summary File. ACO outcomes and characteristics were from the 2014 SSP ACO Public Use File. Service area characteristics were from the American Community Survey.
To generate the ACO service area, we summed the number of beneficiaries per ZIP code tabulation area (ZCTA), rank ordered those ZCTAs from most to least, and identified those ZCTAs comprising 70%.
The social deprivation index (SDI) is a measure of social and material deprivation, constructed by combining a variety of established publicly available socioeconomic measures into a composite measure using a latent variable approach.
Hierarchical Condition Category (HCC) risk score is the weighted mean HCC risk scores across eligibility categories—disabled, end-stage renal disease (ESRD), aged and dual eligible, and aged and non-dual eligible. The mean HCC score for each eligibility category was normalized such that the national average score was 1. For each ACO, we averaged across category–specific HCC scores using the assigned beneficiary share in that category as weights.