Table 2.
Characteristics of the lidA Cohort Study cohort at baselinea
| Variables | Birth cohort 1959 |
Birth cohort 1965 |
Tests of significance |
||||
|---|---|---|---|---|---|---|---|
|
n (%) |
n (%) |
1959 vs 1965 |
|||||
| Males | Females | Males | Females | Males | Females | ||
| 1286 (46.2 %) | 1499 (53.8 %) | 1685 (47.4 %) | 1869 (52.6 %) | ||||
| Sociodemographic variables | |||||||
| Highest school-leaving qualification | without graduation | §) | §) | §) | §) | 9.72 | 30.76 |
| low graduation | 427 (33.2 %) | 356 (23.7 %) | 490 (29.1 %) | 320 (17.1 %) | χ2 | χ2 | |
| middle graduation | 442 (34.4 %) | 705 (47.0 %) | 590 (35.0 %) | 890 (47.6 %) | P = 0.45 | P < 0.001 | |
| high graduation | 381 (29.6 %) | 409 (27.3 %) | 570 (33.8 %) | 630 (33.7 %) | |||
| other | §) | §) | §) | §) | |||
| missing data | 0 | 0 | 0 | 0 | |||
| Occupational status | unskilled/semiskilled worker | 155 (12.1 %) | 170 (11.3 %) | 187 (11.1 %) | 188 (10.1 %) | 3.55 | 10.99 |
| skilled worker | 242 (18.8 %) | 24 (1.6 %) | 301 (17.9 %) | 50 (2.7 %) | χ2 | χ2 | |
| foreman / master craftsman | 66 (5.1 %) | §) | 78 (4.6 %) | §) | P = 0.737 | P = 0.090 | |
| employee without staff responsibilities | 256 (19.9 %) | 753 (50.2 %) | 373 (22.1 %) | 920 (49.2 %) | |||
| employee with staff responsibilities | 524 (40.7 %) | 503 (33.6 %) | 702 (41.7 %) | 634 (33.9 %) | |||
| official | §) | §) | §) | §) | |||
| self-employed person/freelancer | §) | §) | §) | 37 (2.0 %) | |||
| other | §) | §) | §) | §) | |||
| missing data | §) | §) | §) | §) | |||
| Nationality | German | 1242 (96.6 %) | 1459 (97.3 %) | 1588 (94.2 %) | 1784 (95.4 %) | 9.43 | 7.84 |
| other | §) | 40 (2.7 %) | 97 (5.8 %) | §) | χ2 | χ2 | |
| missing data | §) | 0 | 0 | §) | P = 0.002 | P = 0.006 | |
| Employment specific variables | |||||||
| Weekly working hours | full time | 1207 (93.9 %) | 655 (43.7 %) | 1597 (94.8 %) | 790 (42.3 %) | 1.67 | 2.47 |
| part time | 47 (3.7 %) | 670 (44.7 %) | 57 (3.4 %) | 882 (47.2 %) | χ2 | χ2 | |
| other | 32 (2.5 %) | 174 (11.6 %) | 31 (1.8 %) | 197 (10.5 %) | P = 0.435 | P = 0.291 | |
| Years of employment with current employer | M (SD) | 18.69 (10.90) | 16.36 (10.53) | 15.24 (8.86) | 13.40 (8.80) | 9.42 | 8.80 |
| t-statistics | t-statistics | ||||||
| P < 0.001 | P < 0.001 | ||||||
| Personal net income | <1000 Euro | 68 (5.3 %) | 552 (36.8 %) | 70 (4.2 %) | 748 (40.0 %) | 6.52 | 5.46 |
| 1000–<2000 Euro | 493 (38.3 %) | 658 (43.9 %) | 629 (37.3 %) | 781 (41.8 %) | χ2 | χ2 | |
| 2000–<3000 Euro | 393 (30.6 %) | 165 (11.0 %) | 553 (32.8 %) | 187 (10.0 %) | P = 0.163 | P = 0.244 | |
| 3000–<4000 Euro | 127 (9.9 %) | §) | 187 (11.1 %) | §) | |||
| ≥4000 Euro | 131 (10.2 %) | §) | 144 (8.5 %) | §) | |||
| missing data | 74 (5.8 %) | 92 (6.1 %) | 102 (6.1 %) | 101 (5.4 %) | |||
| Work exposure (selection) | |||||||
| ERI (effort-reward imbalance) | M (SD) | 0.56 (0.26) | 0.57 (0.29) | 0.58 (0.27) | 0.57 (0.29) | −1.58 | 0.42 |
| missing data | 235 (18.3 %) | 348 (23.2 %) | 279 (16.6 %) | 430 (23.0 %) | t-statistic | t-statistic | |
| P = 0.115 | P = 0.671 | ||||||
| Over-commitment | M (SD) | 13.20 (4.29) | 13.65 (4.49) | 13.36 (4.20) | 13.29 (4.36) | −1.04 | 2.39 |
| missing data | §) | §) | §) | §) | t-statistic | t-statistic | |
| P = 0.298 | P = 0.017 | ||||||
| Primary health outcomes at baseline | |||||||
| Subjective health status (SF-12) | very good/good/fair | 1123 (87.3 %) | 1251 (83.5 %) | 1504 (89.2 %) | 1639 (87.7 %) | 2.82 | 12.27 |
| bad/ very bad | 163 (12.7 %) | 248 (16.5 %) | §) | 230 (12.3 %) | χ2 | χ2 | |
| missing data | 0 | 0 | §) | 0 | P = 0.105 | P = 0.001 | |
| Physical health (SF-12) | M (SD) | 48.88 (9.11) | 48.46 (9.54) | 50.89 (8.71) | 50.08 (8.98) | −6.08 | −5.04 |
| t-statistic | t-statistic | ||||||
| P < 0.001 | P < 0.001 | ||||||
| Mental health (SF-12) | M (SD) | 52.74 (9.30) | 51.01(10.26) | 52.08(9.48) | 50.84 (10.15) | 1.88 | 0.50 |
| t-statistic | t-statistic | ||||||
| P = 0.060 | P = 0.620 | ||||||
| Depression (BDI-V) | no clinically relevant depression (BDI-V <35) | 987 (76.7 %) | 1038 (69.2 %) | 1298 (77.0 %) | 1340 (71.7 %) | 0.55 | 0.52 |
| clinically relevant depression (BDV-V ≥35) | 109 (8.5 %) | 219 (14.6 %) | 158 (9.4 %) | 263 (14.1 %) | χ2 | χ2 | |
| missing data | 190 (14.8 %) | 242 (16.1 %) | 229 (13.6 %) | 266 (14.2 %) | P = 0.473 | P = 0.481 | |
| Grip strength, right hand | median (IQR) | 49.0 (43.0–54.5) | 29.5 (25.5–33.5) | 50.0 (44.0–46.0) | 31.5 (27.5–35.5) | P = 0.018 | P < 0.001 |
| missing data | 38 (3.0 %) | 63 (4.2 %) | 35 (2.1 %) | 58 (3.1 %) | NP test | NP test | |
| Grip strength, left hand | median (IQR) | 46.0 (40.0–51.5) | 27.0 (23.0–30.5) | 47.5 (41.5–53.0) | 29.0 (25.0–32.5) | P < 0.001 | P < 0.001 |
| missing data | 35 (2.7 %) | 61 (4.1 %) | 34 (2.0 %) | 54 (2.8 %) | NP test | NP test | |
| Employment attitudinal outcomes at baseline | |||||||
| Considering leaving employer | never/several times a year | 1111 (86.4 %) | 1267 (84.5 %) | 1406 (83.4 %) | 1569 (83.9 %) | 4.94 | 0.04, ns |
| at least several times a month | §) | §) | §) | §) | χ2 | χ2 | |
| missing data | §) | §) | §) | §) | P = 0.029 | P = 0.847 | |
| Considering leaving profession | never/several times a year | 1162 (90.4 %) | 1316 (87.8 %) | 1473 (87.4 %) | 1625 (86.9 %) | 5.97 | 0.39, ns |
| at least several times a month | §) | §) | §) | §) | χ2 | χ2 | |
| Considering leaving working | missing data | §) | §) | §) | §) | P = 0.015 | P = 0.565 |
| never/several times a year | 1220 (94.9 %) | 1428 (95.3 %) | 1635 (97.0 %) | 1808 (96.7 %) | 9.12 | 5.56 | |
| at least several times a month | §) | §) | §) | §) | χ2 | χ2 | |
| missing data | §) | §) | §) | §) | P = 0.003 | P = 0.023 | |
Tests of significance compare means/frequencies between the 1959 and 1965 cohorts separately for males and females. Tests of the frequencies were conducted using χ2-tests; tests of the means were conducted using t-tests for independent samples. NP test indicates a nonparametric median test for independent samples.
M, arithmetic mean; SD, standard deviation; IQR, interquartile range; §, no data because less than 20 cases were available; ns, not significant.
aThe database consists of n = 6339 employed persons (ILO-Definition); 246 not employed interviewees were excluded from further analysis (see text).