Table 1.
Baseline characteristics of participants*
| Characteristic | E + P trial |
E-alone trial |
||
| Active HT (N = 8506) | Placebo (N = 8102) | Active HT (N = 5310) | Placebo (N = 5429) | |
| No. (%) | No. (%) | No. (%) | No. (%) | |
| Age, y | ||||
| 50–59 | 2837 (33.4) | 2683 (33.1) | 1639 (30.9) | 1674 (30.8) |
| 60–69 | 3854 (45.3) | 3655 (45.1) | 2386 (44.9) | 2465 (45.4) |
| 70–79 | 1815 (21.3) | 1764 (21.8) | 1285 (24.2) | 1290 (23.8) |
| Race/ethnicity | ||||
| White | 7141 (84.0) | 6805 (84.0) | 4009 (75.5) | 4075 (75.1) |
| Black | 548 (6.4) | 574 (7.1) | 781 (14.7) | 835 (15.4) |
| Hispanic | 471 (5.5) | 415 (5.1) | 319 (6.0) | 332 (6.1) |
| American Indian | 25 (0.3) | 30 (0.4) | 41 (0.8) | 34 (0.6) |
| Asian or Pacific Islander | 194 (2.3) | 169 (2.1) | 86 (1.6) | 78 (1.4) |
| Unknown | 127 (1.5) | 109 (1.3) | 74 (1.4) | 75 (1.4) |
| Education level | ||||
| Less than high school diploma or GED | 2090 (25.7) | 2148 (26.5) | 1769 (33.3) | 1707 (31.4) |
| Some school after high school diploma | 3357 (39.5) | 3060 (37.8) | 2271 (42.8) | 2351 (43.3) |
| College degree or higher | 2915 (34.3) | 2839 (35.0) | 1217 (22.9) | 1327 (24.4) |
| Body mass index, kg/m2 | ||||
| <25 | 2579 (30.3) | 2479 (30.6) | 1110 (20.9) | 1096 (20.2) |
| 25 to <30 | 2992 (35.2) | 2835 (35.0) | 1798 (33.9) | 1915 (35.3) |
| ≥30 | 2899 (34.1) | 2737 (33.8) | 2375 (44.7) | 2385 (43.9) |
| Smoking status | ||||
| Never | 4178 (49.1) | 3999 (49.4) | 2723 (51.3) | 2705 (49.8) |
| Past | 3362 (39.5) | 3157 (39.0) | 1986 (37.4) | 2090 (38.5) |
| Current | 880 (10.3) | 838 (10.3) | 542 (10.2) | 571 (10.5) |
| NSAID use (ever) | ||||
| Yes | 2853 (33.5) | 2767 (34.2) | 1881 (35.4) | 1945 (35.8) |
| No | 5653 (66.5) | 5335 (65.8) | 3429 (64.6) | 3484 (64.2) |
| Total vitamin D intake, IU† | ||||
| <200 | 3320 (39.0) | 3164 (39.1) | 2379 (44.8) | 2350 (43.3) |
| 200 to <400 | 1608 (18.9) | 1547 (19.1) | 885 (16.7) | 937 (17.3) |
| 400 to <600 | 1875 (22.00) | 1775 (21.9) | 1083 (20.4) | 1161 (21.4) |
| ≥600 | 1414 (16.6) | 1347 (16.6) | 731 (13.8) | 727 (13.4) |
| Regional solar radiation, langleys‡ | ||||
| 300–325 | 2517 (29.6) | 2370 (29.3) | 1458 (27.5) | 1501 (27.6) |
| 350 | 2000 (23.5) | 1927 (23.8) | 1118 (21.1) | 1129 (20.8) |
| 375–380 | 965 (11.3) | 905 (11.2) | 640 (12.1) | 662 (12.2) |
| 400–430 | 1334 (15.7) | 1258 (15.5) | 966 (18.2) | 991 (18.3) |
| 475–500 | 1690 (19.9) | 1641 (20.3) | 1123 (21.1) | 1142 (21.0) |
| Total outdoor walking energy expenditure, METs/wk | ||||
| 0 | 2705 (31.8) | 2670 (33.0) | 1951 (36.7) | 1897 (34.9) |
| ≤3.5 | 1585 (18.6) | 1573 (19.4) | 1078 (20.3) | 1064 (19.6) |
| 3.6–7.0 | 1515 (17.8) | 1476 (18.2) | 901 (17.0) | 913 (16.8) |
| >7.0 | 1866 (21.9) | 1877 (23.2) | 950 (17.9) | 1031 (19.0) |
| History of cancer§ | ||||
| Yes | 167 (2.0) | 158 (2.0) | 241 (4.5) | 308 (5.7) |
| No | 8339 (98.0) | 7944 (98.0) | 5069 (95.5) | 5121 (94.3) |
| History of melanoma skin cancer | ||||
| Yes | 11 (0.1) | 10 (0.1) | 6 (0.1) | 10 (0.2) |
| No | 8495 (99.9) | 8092 (99.9) | 5304 (99.9) | 5419 (99.8) |
| History of nonmelanoma skin cancer | ||||
| Yes | 491 (5.8) | 456 (5.6) | 257 (4.8) | 290 (5.3) |
| No | 8015 (94.2) | 7646 (94.4) | 5053 (95.2) | 5137 (94.7) |
| Hormone therapy use | ||||
| Never used | 6277 (73.8) | 6022 (74.3) | 2769 (52.1) | 2769 (51.0) |
| Past user | 1671 (19.6) | 1587 (19.6) | 1871 (35.2) | 1947 (35.9) |
| Current user | 554 (6.5) | 490 (6.0) | 669 (12.6) | 709 (13.1) |
| Dietary modification intervention assignment | ||||
| Not randomly assigned | 6077 (71.4) | 5873 (72.5) | 3656 (68.9) | 3691 (68.0) |
| Intervention | 972 (11.4) | 925 (11.4) | 615 (11.6) | 670 (12.3) |
| Comparison | 1457 (17.1) | 1304 (16.1) | 1039 (19.6) | 1068 (19.7) |
| Calcium vitamin D intervention assignment | ||||
| Not randomly assigned | 3463 (40.7) | 3232 (39.9) | 2236 (42.1) | 2327 (42.9) |
| Active | 2508 (29.5) | 2475 (30.5) | 1531 (28.8) | 1540 (28.4) |
| Placebo | 2535 (29.8) | 2395 (29.6) | 1543 (29.1) | 1562 (28.8) |
*
Percentages may not total 100% because of missing data. E-alone = estrogen alone; E + P = estrogen plus progestin; GED = general equivalency diploma; HT = hormone therapy; NSAID = nonsteroidal anti-inflammatory drug; MET = metabolic equivalent tasks.
†
From diet and supplements.
‡
Based on the mean annual amount of sunlight reaching the clinic site as measured by the US Weather Bureau; 1 langley = 1 g-cal/cm2.
§
History of cancer (cancers diagnosed more than 10 years before enrollment) is defined as any cancer except nonmelanoma skin cancer.