Table 1.
Characteristics of Participants at Baseline, According to Randomized Assignment to Treatment Agent and/or Placeboa
| Characteristic | Active Vitamin D3 and Active Omega-3s (n = 176) | Active Vitamin D3 and Placebo Omega-3s (n = 178) | Placebo Vitamin D3 and Active Omega-3s (n = 176) | Placebo Vitamin D3 and Placebo Omega-3s (n = 190) |
|---|---|---|---|---|
| Age at CTSC visit, mean (SD) | 65.3 (6.3) | 65.2 (6.2) | 65.5 (7.0) | 65.4 (6.7) |
| Sex | ||||
| Male | 96 (54.5) | 94 (52.8) | 98 (55.7) | 112 (58.9) |
| Female | 80 (45.5) | 84 (47.2) | 78 (44.3) | 78 (41.1) |
| Self-reported race/ethnicity | ||||
| Non-Hispanic White | 144 (81.8) | 154 (86.5) | 146 (83.0) | 168 (88.4) |
| Black | 12 (6.8) | 9 (5.1) | 16 (9.1) | 13 (6.8) |
| Hispanic | 6 (3.4) | 1 (0.6) | 3 (1.7) | 5 (2.6) |
| Othersb | 14 (8.0) | 14 (7.9) | 11 (6.3) | 4 (2.1) |
| Subthreshold depression | ||||
| Yesc | 20 (11.4) | 22 (12.4) | 22 (12.5) | 16 (8.4) |
| No | 156 (88.6) | 156 (87.6) | 154 (87.5) | 174 (91.6) |
| 1+ High-risk factors for late-life depression | ||||
| Yesd | 106 (60.2) | 111 (62.4) | 114 (64.8) | 107 (56.3) |
| No | 70 (39.8) | 67 (37.6) | 62 (35.2) | 83 (43.7) |
| Total no. of high-risk factors for late-life depression | ||||
| 0 | 70 (39.8) | 67 (37.6) | 62 (35.2) | 83 (43.7) |
| 1 | 62 (35.2) | 71 (39.9) | 66 (37.5) | 71 (37.4) |
| 2 | 35 (19.9) | 26 (14.6) | 34 (19.3) | 25 (13.2) |
| 3+ | 9 (5.1) | 14 (7.9) | 14 (8.0) | 11 (5.8) |
| Individual High-Risk Group | ||||
| Subthreshold or clinical anxietye | ||||
| Yes | 13 (7.4) | 15 (8.4) | 11 (6.3) | 13 (6.9) |
| No | 163 (92.6) | 163 (91.6) | 164 (93.7) | 176 (93.1) |
| Impaired activities of daily livingf | ||||
| Yes | 7 (4.0) | 3 (1.7) | 7 (4.0) | 4 (2.1) |
| No | 169 (96.0) | 175 (98.3) | 169 (96.0) | 185 (97.9) |
| Problem drinkingg | ||||
| Yes | 26 (14.8) | 28 (15.7) | 32 (18.2) | 30 (15.8) |
| No | 150 (85.2) | 150 (84.3) | 144 (81.8) | 160 (84.2) |
| Physical/functional limitationh | ||||
| Yes | 36 (21.8) | 29 (17.2) | 41 (25.3) | 30 (16.5) |
| No | 129 (78.2) | 140 (82.8) | 121 (74.7) | 152 (83.5) |
| Medical comorbidityi | ||||
| Yes | 23 (13.1) | 25 (14.0) | 22 (12.5) | 23 (12.1) |
| No | 153 (86.9) | 153 (86.0) | 154 (87.5) | 167 (87.9) |
| Cognitive impairmentj | ||||
| Yes | 48 (27.4) | 37 (20.9) | 51 (29.0) | 38 (20.1) |
| No | 127 (72.6) | 140 (79.1) | 125 (71.0) | 151 (79.9) |
| Caregiving burdenk | ||||
| Yes | 3 (1.7) | 13 (7.3) | 12 (6.8) | 7 (3.7) |
| No | 173 (98.3) | 164 (92.7) | 164 (93.2) | 181 (96.3) |
| Low psychosocial supportl | ||||
| Yes | 5 (2.9) | 15 (8.5) | 10 (5.9) | 9 (4.8) |
| No | 170 (97.1) | 162 (91.5) | 160 (94.1) | 180 (95.2) |
Values are shown as n (%) unless otherwise noted. Values for percentages may not add to 100.0 due to rounding.
Others race/ethnicity group included Asians and Pacific Indians, American Indians, Native Hawaiian, other unknown, and missing reported race/ethnicity participants.
Indicated prevention targeted participants with subthreshold depression, but who did not meet DSM-IV criteria for current major depressive disorders or dysthymia, at baseline.
Selective prevention targeted participants with ≥ 1 high-risk factor for late-life depression at baseline; see details in Supplementary Appendix 1 (under E. Approach for selective prevention).
Subthreshold or clinical anxiety was assessed based on core features of anxiety (GAD-2 score ≥ 3 or GAD-7 score ≥ 5) and/or adjudicated anxiety disorder diagnoses in administered diagnostic interviews.36
Impaired activities in daily living was determined based on IADL score (1+ points) reported on OARS multidimensional functional assessment questionnaire.37
Problem drinking was defined based on VITAL-DEP CTSC scoresheet alcohol gating questions and/or AUDIT-C score cutoff ≥ 5.38
Physical/functional function limitation was assessed using the PF-10 of the SF-36.39
Medical comorbidity was derived from the count of major chronic diseases.
Cognitive impairment was determined using published 3MS (range, 0–100) norm-based cut-points, accounting for age, sex, race/ethnicity, and education, for identifying presence of cognitive impairment; for non-Hispanic White men, < 92; for non-Hispanic White women, < 95; for Black and Hispanic participants, < 89; and for Other race/ethnicity participants, < 91.41
Caregiving burden was assessed using Zarit Burden Interview scale42; a cutoff of ≥ 10 and/or self-reported rating of moderately or higher caregiving burden were used to define presence of caregiving burden. The denominator for this group included participants who either did not report caregiver burden or were not providing any information on ill-caregiving.
Psychosocial support was measured using 10-item DSSI43; a cutoff of ≤ 26 for DSSI score was used to define low psychosocial support.44
Abbreviations: 3MS = Modified Mini-Mental State Exam, AUDIT-C = Alcohol Use Disorders Identification Test-Concise, CTSC = Clinical Translational Science Center, DSSI = Duke Social Support Index, GAD = generalized anxiety disorder, IADL = instrumental activities of daily living, OARS = Older Americans Resources and Services, PF-10 = 10-item physical functioning scale, SF-36 = Short Form-36, VITAL-DEP = VITamin D and OmegA-3 TriaL Depression Endpoint Prevention.