TABLE 1.
GEMS participant characteristics overall and by study community presented as n and percent except where indicated (N = 2564)a
| Winston-Salem, NC | Sacramento, CA | Hagerstown, MD | Pittsburgh, PA | |||
|---|---|---|---|---|---|---|
| All | N = 579 | N = 781 | N = 386 | N = 818 | P-valueb | |
| All-cause dementia | 324 (12.6) | 65 (11.2) | 108 (13.8) | 66 (17.1) | 85 (10.4) | 0.005 |
| AD only | 212 (8.3) | 48 (8.3) | 66 (8.5) | 41 (10.6) | 57 (7.0) | 0.20 |
| VaD/AD mixed | 97 (3.8) | 17 (2.9) | 34 (4.4) | 22 (5.7) | 24 (2.9) | 0.061 |
| Follow-up time, y, mean (SD) | 5.7 (1.5) | 5.5 (1.5) | 5.7 (1.4) | 5.7 (1.6) | 5.7 (1.5) | 0.082 |
| Age at randomization, y, mean (SD) | 78.4 (3.2) | 78.3 (3.3) | 78.5 (3.1) | 78.7 (3.4) | 78.2 (3.0) | 0.036 |
| Male | 1,394 (54.4) | 302 (52.2) | 449 (57.5) | 213 (55.2) | 430 (52.6) | 0.15 |
| Non-White | 84 (3.3) | 18 (3.1) | 42 (5.4) | 1 (0.3) | 23 (2.8) | <0.001 |
| Placebo assignment | 1,285 (50.1) | 293 (50.6) | 392 (50.2) | 181 (46.9) | 419 (51.2) | 0.56 |
| Education | <0.001 | |||||
| High school or less | 930 (36.3) | 191 (33.0) | 244 (31.2) | 208 (53.9) | 287 (35.1) | |
| Some college | 628 (24.5) | 177 (30.6) | 202 (25.9) | 76 (19.7) | 173 (21.1) | |
| College graduate | 425 (16.6) | 105 (18.1) | 117 (15.0) | 42 (10.9) | 161 (19.7) | |
| Postgraduate | 581 (22.7) | 106 (18.3) | 218 (27.9) | 60 (15.5) | 197 (24.1) | |
| Smoking status | 0.060 | |||||
| Never | 1,017 (40.4) | 213 (37.4) | 288 (38.0) | 175 (45.9) | 341 (42.2) | |
| Former | 1,391 (55.2) | 327 (57.4) | 441 (58.2) | 188 (49.3) | 435 (53.8) | |
| Current | 110 (4.4) | 30 (5.3) | 29 (3.8) | 18 (4.7) | 33 (4.1) | |
| Pack-years smoking | 0.022 | |||||
| 0 | 1030 (43.4) | 218 (40.0) | 294 (41.5) | 175 (48.6) | 343 (45.0) | |
| >0 to 24 | 692 (29.1) | 185 (33.9) | 213 (30.1) | 84 (23.3) | 210 (27.6) | |
| >24 | 653 (27.5) | 142 (26.1) | 201 (28.4) | 101 (28.1) | 209 (27.4) | |
| Percent of life exposed to SHS | 0.009 | |||||
| ≤1.14 | 615 (24.6) | 129 (22.6) | 185 (24.4) | 110 (29.2) | 191 (24.0) | |
| >1.14 to ≤24.39 | 616 (24.6) | 138 (24.2) | 207 (27.3) | 81 (21.5) | 190 (23.8) | |
| >24.39 to ≤46.43 | 637 (25.4) | 137 (24.0) | 206 (27.1) | 81 (21.5) | 213 (26.7) | |
| >46.43 | 636 (25.4) | 167 (29.2) | 161 (21.2) | 105 (27.9) | 203 (25.5) | |
| NDI, mean (SD) | ||||||
| 5 year | −0.08 (3.09) | −0.55 (3.37) | 0.09 (3.05) | 1.73 (1.99) | −0.77 (2.99) | <0.001 |
| 10 year | −0.08 (3.05) | −0.60 (3.35) | 0.11 (3.01) | 1.68 (1.99) | −0.72 (2.93) | <0.001 |
| 15 year | −0.08 (3.01) | −0.62 (3.32) | 0.10 (2.95) | 1.63 (2.03) | −0.68 (2.90) | <0.001 |
| 20 year | −0.09 (2.99) | −0.61 (3.31) | 0.09 (2.89) | 1.60 (2.08) | −0.68 (2.88) | <0.001 |
| Body mass index, kg/m2, mean (SD) | 27.2 (4.2) | 27.0 (4.3) | 27.2 (4.3) | 27.5 (4.1) | 27.3 (4.3) | 0.25 |
| Alcoholic drinks/wk, mean (SD) | 3.7 (6.6) | 3.3 (6.0) | 5.0 (7.6) | 2.1 (4.7) | 3.5 (6.4) | <0.001 |
| Occupation History | 0.001 | |||||
| Professional | 1484 (57.9) | 357 (61.7) | 473 (60.6) | 206 (53.4) | 448 (54.8) | |
| Sales or clerical | 436 (17.0) | 95 (16.4) | 128 (16.4) | 57 (14.8) | 156 (19.1) | |
| Manual labor | 325 (12.7) | 50 (8.6) | 88 (11.3) | 73 (18.9) | 114 (13.9) | |
| Homemaker | 263 (10.3) | 65 (11.2) | 72 (9.2) | 44 (11.4) | 82 (10.0) | |
| Other | 56 (2.2) | 12 (2.1) | 20 (2.6) | 6 (1.6) | 18 (2.2) | |
| APOE ε4 carrier status | 472 (22.9) | 94 (20.8) | 140 (23.0) | 81 (25.0) | 157 (23.1) | 0.58 |
Abbreviations: AD, Alzheimer’s disease; APOE, apolipoprotein E.; NDI, neighborhood deprivation index; SD, standard deviation; SHS, secondhand smoke; VaD, vascular dementia.
a
Information was missing for the following covariates: APOE ε4 carrier status (n = 500), body mass index (n = 9), alcohol number (n = 38), smoking (n = 46), passive smoking percentage (n = 60), pack-years (n = 189), and NDI (n = 2).
b
Differences by study community were examined using analysis of variance or chi-square tests, as appropriate.