Baseline sociodemographic and clinical characteristics of participants in the study sample
| Characteristic | Overall (n=784) |
| Age at randomisation, mean years±SD | 65.6±6.3 |
| Male sex, n (%) | 458 (58.4) |
| Race, n (%) | |
| White | 537 (68.5) |
| Black | 115 (14.7) |
| Hispanic | 47 (6.0) |
| Other | 85 (10.8) |
| Highest level of education, n (%) | |
| Some high school | 120 (15.3) |
| High school graduate | 231 (29.5) |
| Some college | 253 (32.3) |
| College graduate or more | 180 (23.0) |
| Clinical centre network, n (%) | |
| Canada | 131 (16.7) |
| Western | 100 (12.8) |
| Minnesota/Iowa | 113 (14.4) |
| Ohio/Michigan | 146 (18.6) |
| Northeastern | 77 (9.8) |
| Southeastern | 109 (13.9) |
| Veterans affairs | 108 (13.8) |
| Insurance coverage, n (%) | 715 (91.2) |
| Smoking status, n (%) | |
| Current | 66 (8.4) |
| Former | 402 (51.3) |
| Never | 316 (40.3) |
| Cardiovascular disease, n (%) | 282 (36.0) |
| HbA1C, mean %±SD | 8.3±1.0 |
| Diabetes duration, mean years±SD | 16.3±8.0 |
| Medications, n (%) | |
| Oral hypoglycaemic agents | 628 (80.1) |
| Insulin | 368 (46.9) |
| Aspirin | 477 (60.8) |
| Cardiovascular agents | 80 (10.2) |
| Lipid-lowering agents | 563 (71.8) |
| Bilateral cataract surgery, n (%) | 500 (63.8) |
HbA1C, haemoglobin A1C.