Table 1. Characteristics of Participants at Baseline, According to Randomized Assignment to Omega-3 Fatty Acid or Placeboa.
| Characteristic | No. (%) | |
|---|---|---|
| Omega-3 group (n = 9171)b | Placebo group (n = 9182)b | |
| Age, mean (SD), y | 67.4 (7.1) | 67.5 (7.0) |
| Age groups, y | ||
| 50-54 | 354 (3.9) | 298 (3.3) |
| 55-64 | 2947 (32.1) | 3018 (32.9) |
| 65-74 | 4633 (50.5) | 4598 (50.1) |
| ≥75 | 1237 (13.5) | 1268 (13.8) |
| Sex | ||
| Men | 4674 (51.0) | 4656 (50.7) |
| Women | 4497 (49.0) | 4526 (49.3) |
| Racial or ethnic groupc | ||
| No. | 8982 | 9007 |
| African American or Black | 1683 (18.7) | 1724 (19.1) |
| Asian | 150 (1.7) | 144 (1.6) |
| Hispanic (not African American) | 347 (3.9) | 361 (4.0) |
| Native American or Alaska Native | 80 (0.9) | 70 (0.8) |
| Non-Hispanic White | 6563 (73.1) | 6534 (72.5) |
| Otherd | 159 (1.8) | 174 (1.9) |
| Charlson-Deyo comorbidity index, pointse | ||
| 0 | 7764 (84.7) | 7776 (84.7) |
| 1 | 1206 (13.2) | 1199 (13.1) |
| ≥2 | 201 (2.2) | 207 (2.3) |
| Baseline biomarker levels, median (IQR), %f | ||
| No. | 5591 | 5638 |
| Plasma EPA | 0.5 (0.4-0.7) | 0.5 (0.4-0.7) |
| No. | 5598 | 5639 |
| Plasma DHA | 1.9 (1.5-2.4) | 1.9 (1.6-2.4) |
| Intake of total fish and seafood, median (IQR), servings/wkg | 1.5 (0.9-2.5) | 1.5 (0.9-2.5) |
| Randomization in vitamin D3 portion of trial | ||
| Active agent group | 4608 (50.3) | 4573 (49.8) |
| Placebo group | 4563 (49.8) | 4609 (50.2) |
Abbreviations: DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid.
Full comparison of baseline characteristics can be found in eTable 1 in Supplement 2.
Unless otherwise stated.
Race and ethnicity were reported by participants.
Includes Native Hawaiian or other Pacific Islander, multiple race, unknown race, or unknown ethnicity.
A weighted comorbidity score derived from the sum of the scores for each of several major medical comorbid conditions. Participants were categorized as having 0, 1, or 2 or more points.
Expressed as a percent of the total phospholipid fatty acids.
Assessed by a modified version of Harvard food frequency questionnaire. The combined category includes intake of mackerel, salmon, sardines, bluefish, swordfish, canned tuna, cod, haddock, halibut; breaded fish cakes, pieces, or fish sticks; shrimp, lobster, scallops.