Table 1.
Characteristics of a Depression-free US Heavy Industrial Worker Cohort by Demand and Control Exposure (n = 7,566), 1998–2003
| Variable | Total (n = 7,566) | Demand |
P Value | Control |
P Value | ||||||||||||||||||
| High (n = 2,341) |
Moderate (n = 2,625) |
Low (n = 2,600) |
High (n = 2,125) |
Moderate (n = 2,678) |
Low (n = 2,763) |
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| No. | % | Mean (SD) | No. | % | Mean (SD) | No. | % | Mean (SD) | No. | % | Mean (SD) | No. | % | Mean (SD) | No. | % | Mean (SD) | No. | % | Mean (SD) | |||
| Gender | 0.66a | <0.0001a | |||||||||||||||||||||
| Female | 451 | 6.0 | 132 | 5.6 | 164 | 6.2 | 155 | 6.0 | 77 | 3.6 | 176 | 6.6 | 198 | 7.2 | |||||||||
| Male | 7,115 | 94.0 | 2,209 | 94.4 | 2,461 | 93.8 | 2,445 | 94.0 | 2,048 | 96.4 | 2,502 | 93.4 | 2,565 | 92.8 | |||||||||
| Race | <0.0001a | <0.0001a | |||||||||||||||||||||
| African American | 597 | 7.9 | 152 | 6.5 | 213 | 8.1 | 232 | 8.9 | 216 | 10.2 | 156 | 5.8 | 225 | 8.1 | |||||||||
| Caucasian | 6,727 | 88.9 | 2,142 | 91.5 | 2,333 | 88.9 | 2,252 | 86.6 | 1,873 | 88.1 | 2,396 | 89.5 | 2,458 | 89.0 | |||||||||
| Hispanic | 187 | 2.5 | 36 | 1.5 | 53 | 2.0 | 98 | 3.8 | 26 | 1.2 | 97 | 3.6 | 64 | 2.3 | |||||||||
| Other | 55 | 0.7 | 11 | 0.5 | 26 | 1.0 | 18 | 0.7 | 10 | 0.47 | 29 | 1.1 | 16 | 0.58 | |||||||||
| Educationb | 0.05a | 0.29a | |||||||||||||||||||||
| College/postgraduate | 957 | 23.6 | 274 | 25.3 | 333 | 21.6 | 350 | 24.6 | 206 | 22.3 | 356 | 23.1 | 395 | 24.9 | |||||||||
| Elementary/high school | 3,093 | 76.4 | 809 | 74.7 | 1,210 | 78.4 | 1,074 | 75.4 | 716 | 77.7 | 1,185 | 76.9 | 1,192 | 75.1 | |||||||||
| Smokingb | 0.04a | <0.0001a | |||||||||||||||||||||
| Current | 1,239 | 32.2 | 382 | 34.2 | 460 | 31.2 | 397 | 31.7 | 293 | 32.6 | 511 | 33.7 | 435 | 30.4 | |||||||||
| Former | 1,028 | 26.7 | 267 | 23.9 | 431 | 29.2 | 330 | 26.3 | 282 | 31.4 | 397 | 26.2 | 349 | 24.4 | |||||||||
| Never | 1,577 | 41.0 | 467 | 41.9 | 583 | 39.6 | 527 | 42.0 | 324 | 36.0 | 608 | 40.1 | 645 | 45.1 | |||||||||
| Demandc | 22.1 (5.7) | 24.0 (5.5) | 21.6 (5.8) | 21.1 (5.5) | <0.0001d | ||||||||||||||||||
| Controlc | 10.9 (5.2) | 12.1 (5.4) | 11.1 (5.0) | 9.6 (4.8) | <0.0001d | ||||||||||||||||||
| Age, years | 46.2 (9.5) | 45.2 (10.1) | 48.2 (8.4) | 45.1 (9.8) | <0.0001d | 49.0 (8.1) | 46.8 (9.3) | 43.6 (10.1) | <0.0001d | ||||||||||||||
| Tenure, years | 17.5 (11.2) | 15.8 (11.7) | 20.7 (9.8) | 15.9 (11.3) | <0.0001d | 19.8 (10.7) | 18.2 (11.2) | 15.2 (11.1) | <0.0001d | ||||||||||||||
| Income, dollars | 30,092 | 30,503 | 30,136 | 29,678 | <0.0001d | 31,079 | 30,097 | 29,329 | <0.0001d | ||||||||||||||
| Job grade | 18.0 (9.0) | 18.7 (10.8) | 19.0 (7.5) | 16.5 (8.3) | <0.0001d | 21.9 (8.4) | 18.8 (9.8) | 14.3 (6.8) | <0.0001d | ||||||||||||||
| Body mass index, kg/m2b | 29.7 (5.2) | 29.2 (5.2) | 29.9 (5.2) | 29.9 (5.2) | 0.0001d | 29.8 (5.1) | 29.5 (5.3) | 29.8 (5.3) | 0.19d | ||||||||||||||
| Cholesterol, mg/dLb | 201.9 (39.5) | 200.8 (39.2) | 203.1 (39.3) | 201.5 (39.8) | 0.43d | 204.7 (40.5) | 200.4 (38.7) | 202.0 (39.6) | 0.10d | ||||||||||||||
Abbreviation: SD, standard deviation.
a
P value for a chi-square test.
b
Education data (n = 4,050); smoking data (n = 3,844); body mass index data (n = 4,276); cholesterol data (n = 3,053).
c
Demand scale range, 3–36 (high); control scale range, 2–24 (high).
d
P value for an F test.