Table 1.
Sociodemographic and Clinical Characteristics of Medicare Beneficiaries with Diabetes or Cardiovascular Disease by Size of Assigned Provider Group*
| Size of Assigned Provider Group† | |||||
|---|---|---|---|---|---|
| Small N = 1,940,061 | Medium-sized N = 576,238 | Large N = 586,555 | Total N = 3,102,854 | ||
| Age (%) | |||||
| Under 65 years | 8.6 | 8.4 | 7.8 | 8.4 | |
| 65–69 years | 12.8 | 12.8 | 12.7 | 12.8 | |
| 70–74 years | 20.0 | 20.0 | 20.0 | 20.0 | |
| 75–79 years | 20.6 | 20.9 | 21.1 | 20.7 | |
| 80–84 years | 18.5 | 18.9 | 19.1 | 18.7 | |
| 85 years and older | 19.6 | 19.1 | 19.4 | 19.5 | |
| Female (%) | 58.6 | 58.4 | 57.8 | 58.4 | |
| Race (%) | |||||
| White | 90.1 | 91.0 | 92.0 | 90.6 | |
| Black | 9.9 | 9.0 | 8.0 | 9.4 | |
| Medicaid (%) | 15.3 | 12.7 | 11.6 | 14.1 | |
| ZCTA—level characteristics, mean | |||||
| % below federal poverty line | 9.4 | 8.8 | 8.4 | 9.1 | |
| % with high school degree or higher | 74.8 | 76.3 | 77.6 | 75.6 | |
| % with college degree or higher | 19.2 | 19.6 | 20.0 | 19.4 | |
| Population Area (%) | |||||
| Metropolitan county, 1 million or more | 45.6 | 39.4 | 41.9 | 43.7 | |
| Metropolitan county, less than 1 million | 29.1 | 39.2 | 36.4 | 32.3 | |
| Non-metropolitan county | 25.3 | 21.4 | 21.8 | 23.9 | |
| Chronic Conditions from the CCW (%) | |||||
| Diabetes mellitus | 50.7 | 49.0 | 48.3 | 50.0 | |
| Ischemic heart disease | 74.6 | 73.7 | 72.6 | 74.0 | |
| Acute myocardial infarction | 6.9 | 7.5 | 7.4 | 7.1 | |
| Congestive heart failure | 39.3 | 38.1 | 37.0 | 38.7 | |
| Stroke | 20.2 | 20.3 | 20.0 | 20.2 | |
| Atrial fibrillation | 18.2 | 19.5 | 19.4 | 18.7 | |
| Chronic obstructive pulmonary disease | 28.2 | 26.8 | 25.7 | 27.4 | |
| Chronic kidney disease | 21.3 | 22.5 | 22.8 | 21.8 | |
| Alzheimer’s disease | 4.7 | 4.3 | 4.2 | 4.5 | |
| Dementia | 12.1 | 11.4 | 11.2 | 11.8 | |
| Osteoporosis | 36.9 | 35.9 | 34.8 | 36.3 | |
| History of hip fracture | 3.5 | 3.5 | 3.5 | 3.5 | |
| Depression | 28.2 | 30.1 | 30.1 | 28.9 | |
| Arthritis | 36.9 | 35.9 | 34.8 | 36.3 | |
| Breast cancer | 4.6 | 5.1 | 5.4 | 4.8 | |
| Colon cancer | 2.9 | 2.8 | 2.9 | 2.9 | |
| Prostate cancer | 5.7 | 5.9 | 6.1 | 5.8 | |
| Lung cancer | 1.5 | 1.6 | 1.6 | 1.5 | |
| Endometrial cancer | 0.6 | 0.6 | 0.7 | 0.6 | |
| Cataract | 69.3 | 70.9 | 70.9 | 69.9 | |
| Glaucoma | 24.0 | 23.9 | 23.5 | 23.9 | |
| 3 or more conditions | 73.5 | 73.8 | 72.8 | 73.4 | |
| 4 or more conditions | 70.6 | 71.2 | 70.2 | 70.7 | |
| 5 or more conditions | 37.9 | 37.6 | 36.4 | 37.6 | |
| Mean number of chronic conditions | 5.0 | 5.0 | 4.9 | 5.0 | |
ZCTA = zip code tabulation area; CCW = Chronic condition warehouse
*Tests of statistical significance were conducted using chi-square tests for categorical variables and analysis of variance for continuous variables. Differences across the three categories of provider group size were statistically significant at a P < 0.01 level except for history of hip fracture. Sums of percentages may not equal 100 % due to rounding
† Size of provider groups was categorized according to eligibility for the two major Medicare ACO programs: small groups ineligible for ACO programs (< 5,000 assigned beneficiaries); medium-sized groups eligible for the Shared Savings Program (5,000–14,999 assigned beneficiaries); and large groups eligible for the Pioneer or Shared Savings Program (≥ 15,000 assigned beneficiaries), scaling eligibility thresholds to the 20 % sample