Table 2.
Comparison of Baseline Population Characteristics by Latent Classaof Depressive Symptoms in the Women’s Health Initiative Study on Cognitive Aging (N = 1,989).
| Resilient | Early emerging | Late emerging | Sustained-Mild | Decreasing | Sustained-Moderate | ||
|---|---|---|---|---|---|---|---|
| N = 779 | N = 228 | N = 159 | N = 644 | N = 70 | N = 109 | ||
| Mean (sd) | Mean (sd) | Mean (sd) | Mean (sd) | Mean (sd) | Mean (sd) | ||
| or | or | or | or | or | or | ||
| Population Characteristics | %b (N) | %b (N) | %b (N) | %b (N) | %b (N) | %b (N) | pc |
| Age (years) | 73.00 (3.56) | 73.37 (3.82) | 72.72 (3.45) | 73.83 (4.02) | 72.89 (3.61) | 73.87 (3.71) | <.01 |
| GDS-15d | .25 (.58) | .09 (.3) | 1.36 (1.43) | 2.12 (1.57) | 3.09 (2.25) | 5.79 (2.5) | <.01 |
| Region | .08 | ||||||
| Northeast | 39% (163) | 10% (43) | 8% (33) | 34% (144) | 3% (12) | 6% (23) | |
| South | 37% (110) | 12% (37) | 10% (31) | 33% (100) | 3% (9) | 4% (12) | |
| Midwest | 40% (310) | 14% (109) | 8% (59) | 29% (220) | 4% (30) | 6% (44) | |
| West | 39% (196) | 8% (39) | 7% (36) | 36% (180) | 4% (19) | 6% (30) | |
| Ethnicity | <.01 | ||||||
| African-American | 34% (39) | 10% (11) | 6% (7) | 36% (41) | 3% (3) | 12% (14) | |
| Hispanic White | 17% (4) | 17% (4) | 4% (1) | 35% (8) | 4% (1) | 22% (5) | |
| White (not Hispanic) | 40% (713) | 12% (212) | 8% (150) | 32% (577) | 4% (64) | 4% (86) | |
| Other or Missing | 47% (23) | 2% (1) | 1% (1) | 37% (18) | 4% (2) | 8% (4) | |
| Education | <.01 | ||||||
| Less than high school | 24% (21) | 16% (14) | 1% (1) | 45% (40) | 3% (3) | 11 % (10) | |
| High school | 38% (163) | 11% (46) | 9% (38) | 32% (137) | 4% (16) | 7% (31) | |
| More than high school | 41% (595) | 11% (168) | 8% (120) | 32% (467) | 3% (51) | 5% (68) | |
| Employment | .01 | ||||||
| Currently working | 39% (148) | 10% (37) | 12% (47) | 32% (122) | 3% (11) | 5% (18) | |
| Not working | 40% (76) | 10% (18) | 2% (4) | 40% (76) | 4% (7) | 5% (9) | |
| Retired | 39% (555) | 12% (173) | 7% (108) | 32% (446) | 4% (52) | 6% (82) | |
| Annual income | |||||||
| (dollars) | <.01 | ||||||
| < 9,999 | 31% (129) | 12% (50) | 8% (32) | 39% (165) | 2% (9) | 9% (37) | |
| 10,000–34,999 | 38% (235) | 10% (65) | 8% (52) | 36% (224) | 3% (18) | 5% (31) | |
| 35,000–49,999 | 43% (185) | 13% (58) | 8% (34) | 26% (110) | 4% (18) | 6% (25) | |
| 50,000–74,999 | 48% (132) | 9% (26) | 10% (28) | 24% (66) | 5% (13) | 4% (12) | |
| 75,000 or more | 45% (79) | 14% (25) | 5% (9) | 31% (55) | 4% (7) | 1% (1) | |
| Don’t know | 32% (19) | 7% (4) | 7% (4) | 41% (24) | 8% (5) | 5% (3) | |
| Lifestyle | |||||||
| Smoking status | 0.55 | ||||||
| Never smoked | 40% (447) | 12% (130) | 8% (89) | 30% (337) | 3% (38) | 6% (65) | |
| Past smoker | 38% (292) | 12% (91) | 8% (62) | 34% (266) | 3% (28) | 5% (36) | |
| Current Smoker | 37% (40) | 6% (7) | 7% (8) | 38% (41) | 4% (4) | 7% (8) | |
| Alcohol use | 0.03 | ||||||
| Non-drinker | 42% (103) | 14% (34) | 8% (20) | 29% (71) | 4% (11) | 3% (7) | |
| Past drinker | 32% (112) | 9% (32) | 10% (33) | 39% (134) | 3% (10) | 7% (26) | |
| Less than 1 drink / day | 39% (449) | 12% (137) | 8% (89) | 32% (364) | 4% (42) | 6% (67) | |
| More than 1 drink / day | 46% (115) | 10% (25) | 7% (17) | 30% (75) | 3% (7) | 4% (9) | |
| Moderate or strenuous physical activities ≥ 20 minutes | <.01 | ||||||
| No activity | 35% (394) | 10% (113) | 8% (93) | 37% (415) | 3% (35) | 7% (78) | |
| Some activity | 37% (40) | 17% (18) | 12% (13) | 25% (27) | 3% (3) | 6% (6) | |
| 2–4 episodes/wk | 44% (180) | 13% (53) | 4% (18) | 30% (125) | 5% (19) | 4% (18) | |
| ≥episodes/week | 48% (165) | 13% (44) | 10% (35) | 23% (77) | 4% (13) | 2% (7) | |
| Physical Health | |||||||
| Hypertension | <.01 | ||||||
| No | 42% (532) | 11% (143) | 8% (98) | 29% (368) | 4% (52) | 5% (68) | |
| Yes | 34% (247) | 12% (85) | 8% (61) | 38% (276) | 2% (18) | 6% (41) | |
| High Cholesterol | .53 | ||||||
| No | 40% (657) | 11% (187) | 8% (130) | 32% (526) | 3% (54) | 5% (87) | |
| Yes | 35% (122) | 12% (41) | 8% (29) | 34% (118) | 5% (16) | 6% (22) | |
| Diabetes | <.01 | ||||||
| No | 40% (753) | 12% (224) | 8% (151) | 32% (599) | 4% (69) | 5% (94) | |
| Yes | 26% (26) | 4% (4) | 8% (8) | 45% (45) | 1% (1) | 15% (15) | |
| Cardiovascular disease | .01 | ||||||
| No | 41% (685) | 11% (187) | 8% (133) | 31% (527) | 4% (62) | 5% (86) | |
| Yes | 30% (94) | 13% (41) | 8% (26) | 38% (117) | 3% (8) | 7% (23) | |
| Hormone treatment | |||||||
| ever | .30 | ||||||
| No | 41% (447) | 11% (123) | 8% (89) | 30% (329) | 4% (38) | 5% (57) | |
| Yes | 37% (332) | 12% (105) | 8% (70) | 35% (315) | 4% (32) | 6% (52) | |
| Baseline exposure | |||||||
| PM2.5 (3-year average) | 12.78 (2.4) | 12.83 (2.4) | 12.64 (2.16) | 12.66 (2.46) | 12.56 (2.38) | 13.14 (2.52) | .42 |
a
Group membership estimated from the latent class model that includes the initial level of depressive symptoms with both fixed effects and random intercept, linear and quadratic change of follow-up time, initial WHISCA age, and attrition (yes/no if participant dropped out at the subsequent assessment time) to account for heterogeneity in the longitudinal profiles of depressive symptoms.
b
Percentage reported above represent row percentages.
c
p values calculated from chi-square or fisher exact tests for categorical variables, from ANOVA F-tests for continuous variables
d
GDS-15 = Geriatric Depression Scale-15