Table 2.
Sociodemographic characteristics of the study sample
| N (2398 at baseline) or mean (standard deviation) |
Percentage | |
|---|---|---|
| Covariates | ||
| Age | ||
| 45–54 years | 840 | 35.3 |
| 55–60 years | 767 | 31.8 |
| > 60 years | 791 | 32.9 |
| Marital Status | ||
| Widowed, divorced, separated | 177 | 7.4 |
| Single | 122 | 5.1 |
| Married | 2099 | 87.5 |
| Registrar General Social Class | ||
| Non-manual | 780 | 32.6 |
| Manual | 1610 | 67.4 |
| Employment status | ||
| Employed | 1107 | 43.6 |
| Self-employed | 152 | 6.3 |
| Unemployed | 362 | 15.1 |
| Retired | 770 | 32.3 |
| Smoking status | ||
| Non-smoker | 431 | 18.0 |
| Ex-smoker | 907 | 37.9 |
| Current smoker | 1054 | 44.1 |
| BMI | 26.4 (3.64) | Not applicable |
| Alcohol consumption ccs/week | 15,414 (199) | Not applicable |
| Physical activity | 130,252 (134355) | Not applicable |
| Noise at work | ||
| 1 | 747 | 32.1 |
| 2 | 878 | 37.8 |
| 3 | 700 | 30.1 |
| Noise variables | ||
| Noise exposure (LAeq 16 h) | ||
| 51-55dBA | 2101 | 72.6 |
| 56-60dBA | 247 | 8.5 |
| 61-65dBA | 374 | 12.9 |
| 66-70dBA | 174 | 6.0 |
| Noise sensitivity | ||
| Lowest tertile | 808 | 34.6 |
| Mid tertile | 773 | 33.1 |
| Highest tertile | 753 | 32.3 |
| Noise annoyance | ||
| Never, Seldom, Sometimes | 2262 | 96.4 |
| Often, Always | 84 | 3.6 |
| Cardiovascular variables | ||
| CHD prior to phase 2 | ||
| No | 2345 | 97.8 |
| Yes | 53 | 2.2 |
| IHD mortality between phase 2 and phase 4 | ||
| No | 1976 | 82.4 |
| Yes | 422 | 17.6 |
| IHD morbidity between phase 2 and phase 4 | ||
| No | 1659 | 69.2 |
| Yes | 739 | 30.8 |
| Psychological variables | ||
| GHQ2 | ||
| No | 7177 | 77.7 |
| Yes | 490 | 22.3 |
| GHQ3 | ||
| No | 1319 | 76.2 |
| Yes | 410 | 23.8 |
| GHQ4 | ||
| No | 1124 | 75.3 |
| Yes | 369 | 24.7 |