Table 1. Baseline characteristics of the AREDS and AREDS2 cohorts.
| AREDS | AREDS2 | P Valuea | |
|---|---|---|---|
| Subject-level variables | |||
| Number of subjects | N = 2721 | N = 1700 | |
| Age | |||
| Mean (SD) | 68.7 (4.9) | 71.5 (7.7) | 8.0 × 10−43 |
| Median (range) | 68.5 (55.3–81.2) | 73 (50–86) | |
| Sex (n, %) | |||
| Female | 1527 (56) | 997 (59) | 0.11 |
| Male | 1194 (44) | 703 (41) | |
| Education | |||
| ≤High school | 906 (33) | 485 (29) | 3.0 × 10−3 |
| >High school | 1814 (67) | 1189 (70) | |
| Missing | 1 (0) | 28 (2) | |
| Smoking (n, %) | |||
| Never smoked | 1272 (47) | 739 (43) | 0.08 |
| Former smoker | 1288 (47) | 863 (51) | |
| Current smoker | 161 (6) | 98 (6) | |
| Treatment | Placebo: 842 (31) | Placebo: 409 (24) | |
| Antioxidants alone: 850 (31) | L+Z: 418 (25) | ||
| Zinc: 507 (19) | LCPUFA: 451 (27) | ||
| Antioxidants+Zinc: 522 (19) | L+Z plus LCPUFA: 422 (25) | ||
| Genetic risk score (GRS) | |||
| Mean (SD) | 1.00 (0.14) | 1.08 (0.13) | 8.1 × 10−67 |
| Median (range) | 1.01 (0.61–1.45) | 1.08 (0.58–1.42) | |
| Follow-up time | |||
| Mean (SD) | 10.3 (1.7) | 4.8 (0.5) | |
| Median (range) | 10.9 (1.8–12.6) | 4.9 (2.1–5.9) | |
| Eye-level variables | |||
| Number of eyes | N = 5017 | N = 2830 | |
| Baseline AREDS AMD severity score | |||
| Mean (SD) | 3.0 (2.3) | 6.3 (1.3) | <1.0 × 10−300 |
| Median (range) | 2 (1–8) | 7 (1–8) | <1.0 × 10−300 |
| 1–3 (n, %) | 3125 (62) | 119 (4) | <1.0 × 10−300 |
| 4–6 (n, %) | 1293 (26) | 1211 (43) | |
| 7–8 (n, %) | 599 (12) | 1500 (53) |
a
P-values were from two-sided t-test for continuous variables, and were from chi-square test for categorical variables. Wilcoxon rank-sum test was applied to test the median of the eye-level baseline severity score.