Table 1.
Characteristics of the Study Population - Combined Medical
| Low Risk (<25%) | Medium Risk (25–75%) | High Risk (75–90%) | Very High Risk (≥90%) | |
|---|---|---|---|---|
| Medicare | ||||
| Number patients | 966,108 | 1,931,170 | 580,012 | 386,178 |
| Mean age | 75.08 | 77.74 | 81.91 | 82.95 |
| % male | 42.3 | 46.2 | 46.2 | 49.9 |
| Mean number comorbidities | 2.13 | 1.98 | 1.96 | 2.47 |
| Metastatic Cancer (%) | 0.02 | 0.74 | 2.24 | 12.12 |
| Liver disease (%) | 0.72 | 1.08 | 1.39 | 2.71 |
| Renal Failure (%) | 1.45 | 5.41 | 9.82 | 22.98 |
| Hypertension (%) | 13.13 | 11.20 | 9.59 | 9.03 |
| CHF (%) | 4.91 | 12.27 | 17.81 | 43.88 |
| Teaching Intensity1 | ||||
| RB ratio = 0 | 26.0 | 49.4 | 14.8 | 9.9 |
| RB ratio >0–0.25 | 24.1 | 50.7 | 15.2 | 10.0 |
| RB ratio 0.26–0.60 | 23.8 | 50.3 | 15.3 | 10.0 |
| RB ratio >0.60 | 22.9 | 51.4 | 15.5 | 10.2 |
| VA | ||||
| Number patients | 36,470 | 72,935 | 21,910 | 14,590 |
| Mean age | 58.0 | 69.1 | 75.4 | 76.9 |
| % male | 97.0 | 98.5 | 98.8 | 99.0 |
| Mean number comorbidities | 2.0 | 2.1 | 2.4 | 3.2 |
| Metastatic Cancer (%) | 0.0 | 0.2 | 1.3 | 13.6 |
| Liver disease (%) | 0.9 | 4.3 | 6.1 | 10.6 |
| Renal Failure (%) | 0.8 | 3.5 | 11.4 | 29.0 |
| Hypertension (%) | 73.9 | 62.2 | 48.3 | 42.3 |
| CHF (%) | 1.7 | 6.6 | 15.3 | 29.3 |
| Teaching Intensity1 | ||||
| RB ratio = 0 | 20.1 | 50.7 | 17.8 | 11.5 |
| RB ratio >0–0.25 | 24.0 | 49.8 | 15.8 | 10.4 |
| RB ratio 0.26–0.60 | 25.5 | 50.2 | 14.7 | 9.6 |
| RB ratio >0.60 | 25.6 | 49.8 | 14.6 | 10.0 |
1 Teaching intensity is presented as a row percentage (specifically, the percentage of patients in each category of teaching hospitals who are within that risk stratum). All other percentages given are column percentages (prevalence of each comorbidity among patients in each risk stratum).