Table 1.
Baseline Characteristics of the Study Population
| Characteristic | Diabetic Macular Edema (n = 13115) | Controls (n = 49653) | P Value |
|---|---|---|---|
| Age, mean (SD), y | 76 (6.0) | 76 (6.5) | .001 |
| Male sex, No. (%) | 5273 (40.2) | 21726 (43.8) | < .001 |
| Race/ethnicity, No. (%) | < .001 | ||
| Black | 1529 (11.7) | 5617 (11.3) | |
| White | 10795 (82.3) | 41470 (83.5) | |
| Other/unknown | 791 (6.0) | 2566 (5.2) | |
| Comorbid condition history, No. (%)a | |||
| Age-related macular degeneration | 894 (6.8) | — | |
| Any malignancy | 237 (1.8) | 956 (1.9) | .38 |
| Cataracts | 8250 (62.9) | 15656 (31.5) | < .001 |
| Cerebrovascular disease | 2902 (22.1) | 9461 (19.1) | < .001 |
| Chronic obstructive pulmonary disease | 3064 (23.4) | 11914 (24.0) | .13 |
| Coronary heart disease | 5963 (45.5) | 19737 (39.7) | < .001 |
| Dementia | 388 (3.0) | 2998 (6.0) | < .001 |
| Glaucoma | 3210 (24.5) | 6426 (12.9) | < .001 |
| Hypertension | 10999 (83.9) | 39365 (79.3) | < .001 |
| Peripheral vascular disease | 3092 (23.6) | 9511 (19.2) | < .001 |
| Renal disease | 1185 (9.0) | 2955 (6.0) | < .001 |
| US geographic region, No. (%) | < .001 | ||
| Midwest | 3302 (25.2) | 13113 (26.4) | |
| Northeast | 2920 (22.3) | 10059 (20.3) | |
| South | 5199 (39.6) | 20197 (40.7) | |
| West | 1694 (12.9) | 6284 (12.7) | |
| Year of incidence, No. (%)b | |||
| 2000 | 2564 (19.6) | — | |
| 2001 | 2517 (19.2) | — | |
| 2002 | 2608 (19.9) | — | |
| 2003 | 2542 (19.4) | — | |
| 2004 | 2884 (22.0) | — |
a
Patients with evidence of any retina disorder (ICD-9-CM code 362.xx) were excluded from the control group.
b The index date for controls was set arbitrarily to July 1, 2002.