Table 1.
Demographic and Health Characteristics of Participants and Controls, Silver Sneakers (SS) Program, Group Health Cooperative of Puget Sound, Seattle, Washington, 1998–2003
| Characteristic | Controls (n = 9035) | SS Participants (n = 4766) | P Valuea |
|---|---|---|---|
| Demographics | |||
| Age, y, mean (SD) | 72 (5) | 73 (5) | .09 |
| Women, n (%) | 5987 (66) | 3012 (63) | <.001 |
| Comorbidities,b n (%) | |||
| Arthritis | 1450 (16.1) | 990 (20.8) | <.001 |
| Coronary artery disease | 1087 (12.0) | 593 (12.4) | .48 |
| Inclusion in health plan's heart registry | 1681 (18.6) | 917 (19.2) | .36 |
| Congestive heart failure | 412 (4.6) | 145 (3.0) | <.001 |
| Hypertension | 2233 (24.7) | 1129 (23.7) | .18 |
| Depression | 816 (9.0) | 458 (9.6) | .27 |
| Diabetes | 1427 (15.8) | 620 (13.0) | <.001 |
| Inclusion in health plan's diabetes registry | 1413 (15.6) | 618 (13.0) | <.001 |
| RxRisk,c $, mean (SD) | 2557 (1676) | 2416 (1443) | <.001 |
| Preventive services index,d mean (SD) | 1.8 (1.7) | 2.4 (1.8) | <.001 |
Unadjusted comparisons were made using t test for unequal variance (continuous variables) or chi-square test (dichotomous variables).
Comorbid conditions (arthritis, coronary artery disease, congestive heart failure, hypertension, depression, and diabetes) were ascertained from problem lists for outpatient visits according to International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic codes (19).
RxRisk is a measure of chronic disease burden and comorbidity (20) and is expressed as predicted 6-month costs in 2003 dollars. Higher costs represent higher comorbidity.
Preventive services index is the sum of the number of times a person received preventive services in the 2 years preceding the index date. The following services were counted: fecal occult blood test, flexible sigmoidoscopy, screening mammogram, prostate cancer screening, influenza vaccine, and pneumococcal vaccine. Counts ranged from 0 to 8.