| IQ quintile‡ | p Value* | ||||||
| 1 (⩽86) | 2 (87–99) | 3 (100–11) | 4 (111–22) | 5 (>122) | |||
| Numbers | 817 | 759 | 814 | 934 | 992 | ||
| Percentage† | |||||||
| Age at telephone interview, years | ⩽34 | 15.4 | 16.6 | 12.3 | 11.5 | 6.9 | <0.001 |
| 35–39 | 65.6 | 67.2 | 70.4 | 72.1 | 64.8 | ||
| ⩾40 | 19.0 | 16.2 | 17.3 | 16.5 | 28.3 | ||
| Army income, US$/month‡ | 83–119 | 19.6 | 29.1 | 37.6 | 42.6 | 54.8 | <0.001 |
| 120–144 | 59.7 | 53.5 | 50.4 | 47.9 | 41.3 | ||
| 145 | 20.7 | 17.4 | 12.0 | 9.6 | 4.0 | ||
| Place of service‡ | Served in USA only | 15.3 | 15.9 | 17.5 | 19.8 | 24.0 | <0.001 |
| Other overseas posting | 24.9 | 24.9 | 24.3 | 25.2 | 29.3 | ||
| Ever served in Vietnam | 59.8 | 59.2 | 58.2 | 55.1 | 46.7 | ||
| Ethnic group‡ | White | 56.7 | 74.4 | 85.2 | 91.2 | 95.8 | <0.001 |
| Black | 31.6 | 17.1 | 8.7 | 3.9 | 1.8 | ||
| Other | 11.8 | 8.5 | 6.1 | 5.0 | 2.5 | ||
| Marital status | Married | 68.2 | 73.3 | 72.4 | 76.5 | 75.4 | <0.001 |
| Divorced/widowed/separated | 23.1 | 20.0 | 19.4 | 15.1 | 14.3 | ||
| Never married | 8.7 | 6.7 | 8.2 | 8.5 | 10.3 | ||
| Smoking habit | Never smoked | 24.0 | 21.7 | 25.1 | 26.6 | 32.2 | <0.001 |
| Former smoker | 18.8 | 24.2 | 25.3 | 29.5 | 30.8 | ||
| Current smoker | 57.2 | 54.1 | 49.5 | 43.9 | 37.0 | ||
| Alcohol consumption | Never drinker | 12.1 | 10.4 | 10.9 | 9.7 | 6.9 | <0.001 |
| Non-drinker | 18.6 | 16.7 | 13.7 | 14.1 | 12.1 | ||
| Drinker: non-binger | 28.0 | 30.1 | 30.5 | 34.3 | 40.9 | ||
| Drinker: 1–3 binges/month | 23.3 | 22.7 | 24.5 | 24.7 | 26.3 | ||
| Drinker: 4–7 binges/month | 9.1 | 10.0 | 9.6 | 7.3 | 7.8 | ||
| Drinker: ⩾8 binges/month | 8.9 | 10.0 | 10.9 | 9.9 | 6.1 | ||
| Educational attainment | Grade ⩾13 | 24.1 | 31.8 | 44.2 | 60.9 | 84.4 | <0.001 |
| Grade 12 | 42.3 | 49.8 | 47.7 | 36.2 | 14.3 | ||
| Grade ⩽11 | 33.6 | 18.5 | 8.1 | 2.9 | 1.3 | ||
| Family income, $/year | >40 000 | 7.0 | 10.8 | 17.5 | 27.3 | 38.8 | <0.001 |
| 20 001–40 000 | 42.7 | 53.2 | 54.7 | 53.4 | 47.4 | ||
| ⩽20 000 | 50.3 | 36.0 | 27.9 | 19.4 | 13.8 | ||
| Generalised anxiety disorder | Yes | 14.8 | 12.8 | 8.1 | 7.3 | 7.0 | <0.001 |
| Posttraumatic stress disorder | Yes | 11.1 | 9.4 | 6.2 | 6.8 | 4.3 | <0.001 |
| Depression | Yes | 8.6 | 7.9 | 5.6 | 6.1 | 4.7 | <0.001 |
| Somatic disease | Yes | 16.5 | 14.1 | 13.6 | 12.2 | 11.2 | <0.001 |
| Mean† (SD) | |||||||
| Occupational prestige§ | 23.7 (0.39) | 26.4 (0.44) | 29.6 (0.47) | 35.0 (0.49) | 43.7 (0.49) | <0.001 | |
| Height, m | 1.77 (0.08) | 1.78 (0.07) | 1.78 (0.07) | 1.79 (0.07) | 1.79 (0.07) | <0.001 | |
| FEV1, litres | 3.81 (0.66) | 3.94 (0.64) | 4.05 (0.63) | 4.11 (0.66) | 4.21 (0.63) | <0.001 | |
| Total cholesterol, mmol/l | 5.56 (1.11) | 5.52 (1.05) | 5.55 (1.06) | 5.45 (1.09) | 5.44 (1.06) | 0.004 | |
| HDL-cholesterol, mmol/l | 1.19 (0.36) | 1.14 (0.33) | 1.13 (0.29) | 1.16 (0.31) | 1.15 (0.31) | 0.17 | |
| Systolic blood pressure, mm Hg | 124.5 (13.3) | 122.8 (12.1) | 124.0 (11.5) | 121.9 (11.6) | 122.3 (11.7) | <0.001 | |
| Diastolic blood pressure, mm Hg | 85.4 (10.1) | 84.6 (9.9) | 84.6 (9.5) | 83.1 (8.9) | 83.5 (8.9) | <0.001 | |
| Pulse rate, beats/minute | 82.1 (12.9) | 81.9 (12.8) | 81.5 (11.6) | 81.0 (11.9) | 80.6 (12.4) | <0.001 | |
| Blood glucose, mg/dl§ | 95.1 (0.16) | 93.6 (0.12) | 93.0 (0.12) | 92.9 (0.12) | 92.5 (0.11) | <0.001 | |
| Body mass index, kg/m2 | 26.3 (4.2) | 26.0 (3.6) | 26.1 (3.8) | 25.8 (3.6) | 25.6 (3.4) | <0.001 | |
FEV1, Forced expiratory volume in one second; HDL, high-density lipoprotein. All data were collected during telephone survey and medical examination unless otherwise indicated. *p Value for trend for dichotomous and continuous measures; otherwise, p value for heterogeneity. †All means and percentages (apart from age) are adjusted for age. ‡Data extracted from military records. §Geometric mean with SE of logged variable in brackets.