Table 1.
Baseline sample characteristics
| Control subjects | SS participants | P value* | |
|---|---|---|---|
| n | 1,413 | 618 | |
| Demographics | |||
| Age (years) | 72 ± 5 | 72 ± 5 | 0.47 |
| Sex (% female) | 835 (59) | 312 (50) | <0.001 |
| Comorbidities† | |||
| RxRisk ($) | 3,498 ± 2,356 | 3,300 ± 1,990 | 0.05 |
| Arthritis | 212 (15) | 128 (21) | 0.002 |
| Coronary artery disease | 294 (21) | 140 (23) | 0.35 |
| Heart registry | 473 (33) | 230 (37) | 0.10 |
| Congestive heart failure | 134 (9) | 47 (9) | 0.17 |
| Hypertension | 503 (36) | 241 (39) | 0.14 |
| Depression | 118 (8) | 52 (8) | 0.96 |
| A1C (%)‡ | 7.48 ± 1.4 | 7.38 ± 1.28 | 0.12 |
| Serum HDL‡ | 49 ± 13 | 49 ± 13 | 0.94 |
| Total cholesterol‡ | 207 ± 46 | 202 ± 44 | 0.04 |
| Preventive services index§ | 1.4 ± 1.6 | 1.8 ± 1.7 | <0.001 |
Data are means ± SD or n (%) unless indicated otherwise. n = 2,031.
Unadjusted comparisons using t test for unequal variance (continuous variables) or χ2 test (dichotomous variables).
RxRisk is expressed as predicted 6-month costs. Higher costs represent higher comorbidity; comorbid conditions (arthritis, coronary artery disease, congestive heart failure, hypertension, diabetes, and depression) were derived from problem lists for outpatient visits.
A1C (control subjects, n = 1,325; SS participants, n = 588); serum HDL and total cholesterol (n = 907 and n = 440, respectively).
Preventive services index is the total number of preventive services that an individual used in the 2 years preceding the index date (colon cancer screening [fecal occult blood test or flexible sigmoidoscopy], a screening mammogram, prostate cancer screening, an influenza vaccine, or a pneumococcal vaccine [range 0–8]).