TABLE 3. Prospective Analysis: Psychological, Social, and Mechanical Factors as Independent Variables and Low WAI (<37 points) at Follow-Up as Outcome—Binary Logistic Regressions, Odds Ratios Adjusted for Baseline WAI.
| Baseline Exposure as Predictor | Average Exposure as Predictorb | ||||
|---|---|---|---|---|---|
| Work Exposure | Confounders Includeda | n | OR (99% CI) | n | OR (99% CI) |
| Decision demands | |||||
| Category | |||||
| Low | 165 | 1 (reference) | 159 | 1 (reference) | |
| Middle | 833 | 0.50 (0.26–0.96)* | 714 | 0.50 (0.26–0.96)* | |
| High | 1064 | 0.61 (0.32–1.16) | 1120 | 0.62 (0.33–1.16) | |
| Continuous | 2062 | 0.84 (0.64–1.10) | 1993 | 0.84 (0.62–1.14) | |
| Quantitative demands | |||||
| Category | |||||
| Low | 672 | 1 (reference) | 548 | 1 (reference) | |
| Middle | 817 | 1.37 (0.87–2.17) | 1020 | 0.98 (0.62–1.55) | |
| High | 627 | 1.55 (0.95–2.53) | 507 | 1.56 (0.93–2.64) | |
| Continuous | 2116 | 1.25 (0.97–1.61) | 2075 | 1.31 (0.98–1.74) | |
| Role clarity | |||||
| Category | |||||
| Low | 61 | 1 (reference) | 42 | 1 (reference) | |
| Middle | 225 | 0.75 (0.27–2.04) | 173 | 0.50 (0.16–1.49) | |
| High | 1845 | 0.57 (0.23–1.39) | 1906 | 0.29 (0.11–0.79)* | |
| Continuous | 2131 | 0.81 (0.64–1.03) | 2121 | 0.68 (0.52–0.90)** | |
| Role conflict | |||||
| Category | |||||
| Low | 1124 | 1 (reference) | 1258 | 1 (reference) | |
| Middle | 818 | 1.38 (0.93–2.07) | 708 | 1.30 (0.87–1.95) | |
| High | 188 | 2.29 (1.28–4.12)** | 156 | 2.92 (1.59–5.38)** | |
| Continuous | 2130 | 1.42 (1.12–1.80)** | 2122 | 1.51 (1.15–2.00)** | |
| Positive challenge | |||||
| Category | |||||
| Low | 65 | 1 (reference) | 54 | 1 (reference) | |
| Middle | 298 | 0.42 (0.17–1.04) | 247 | 0.45 (0.17–1.17) | |
| High | 1658 | 0.35 (0.15–0.80)* | 1639 | 0.26 (0.11–0.64)** | |
| Continuous | 2021 | 0.75 (0.58–0.96)* | 1940 | 0.58 (0.44–0.78)** | |
| Control over work intensity | |||||
| Category | |||||
| Low | 525 | 1 (reference) | 494 | 1 (reference) | |
| Middle | 389 | 0.72 (0.40–1.29) | 450 | 0.74 (0.43–1.30) | |
| High | 1214 | 0.98 (0.60–1.59) | 1164 | 0.95 (0.57–1.57) | |
| Continuous | 2128 | 1.01 (0.83–1.22) | 2108 | 0.99 (0.81–1.22) | |
| Decision control | |||||
| Category | |||||
| Low | 653 | 1 (reference) | 555 | 1 (reference) | |
| Middle | 774 | 0.99 (0.63–1.55) | 806 | 0.83 (0.53–1.31) | |
| High | 615 | 1.14 (0.69–1.89) | 628 | 0.89 (0.52–1.52) | |
| Continuous | 2042 | 0.97 (0.75–1.26) | 1989 | 0.90 (0.67–1.20) | |
| Predictability during the next month | |||||
| Category | |||||
| Low | 67 | 1 (reference) | 40 | 1 (reference) | |
| Middle | 183 | 0.62 (0.20–1.94) | 160 | 0.55 (0.16–1.92) | |
| High | 1888 | 0.85 (0.32–2.25) | 1926 | 0.44 (0.15–1.33) | |
| Continuous | 2138 | 0.94 (0.73–1.21) | 2126 | 0.86 (0.64–1.16) | |
| Support from immediate superior | |||||
| Category | |||||
| Low | 166 | 1 (reference) | 127 | 1 (reference) | |
| (continues) | |||||
| Baseline Exposure as Predictor | Average Exposure as Predictorb | ||||
|---|---|---|---|---|---|
| Work Exposure | Confounders Includeda | n | OR (99% CI) | n | OR (99% CI) |
| Middle | Social climate | 401 | 0.91 (0.42–1.95) | 380 | 0.49 (0.23–1.05) |
| High | Fair leadership | 1499 | 0.89 (0.41–1.96) | 1473 | 0.40 (0.18–0.89)* |
| Continuous | 2066 | 0.87 (0.65–1.15) | 1980 | 0.72 (0.50–1.02) | |
| Empowering leadership | |||||
| Category | |||||
| Low | 505 | 1 (reference) | 515 | 1 (reference) | |
| Middle | 714 | 0.87 (0.56–1.37) | 688 | 0.69 (0.44–1.08) | |
| High | 913 | 0.74 (0.46–1.18) | 914 | 0.59 (0.37–0.94)* | |
| Continuous | 2132 | 0.88 (0.74–1.06) | 2117 | 0.75 (0.61–0.92)** | |
| Fair leadership | |||||
| Category | |||||
| Low | 126 | 1 (reference) | 101 | 1 (reference) | |
| Middle | 398 | 0.61 (0.30–1.26) | 315 | 0.71 (0.32–1.53) | |
| High | 1596 | 0.54 (0.29–1.02) | 1668 | 0.41 (0.21–0.83)* | |
| Continuous | 2120 | 0.81 (0.66–1.01) | 2084 | 0.64 (0.50–0.81)** | |
| Innovative climate | |||||
| Category | |||||
| Low | Positive challenge | 125 | 1 (reference) | 94 | 1 (reference) |
| Middle | Support from immediate superior | 570 | 1.73 (0.77–3.88) | 469 | 1.05 (0.43–2.56) |
| High | Fair leadership | 1211 | 1.58 (0.66–3.82) | 1176 | 1.22 (0.46–3.23) |
| Continuous | Social climate | 1906 | 1.27 (0.87–1.86) | 1739 | 1.55 (0.95–2.54) |
| Social climate | |||||
| Category | |||||
| Low | 89 | 1 (reference) | 77 | 1 (reference) | |
| Middle | 509 | 0.83 (0.38–1.83) | 395 | 0.83 (0.35–1.94) | |
| High | 1520 | 0.62 (0.29–1.33) | 1613 | 0.55 (0.25–1.24) | |
| Continuous | 2118 | 0.89 (0.69–1.15) | 2085 | 0.66 (0.50–0.89)** | |
| Human resource primacy | |||||
| Category | |||||
| Low | 470 | 1 (reference) | 471 | 1 (reference) | |
| Middle | 799 | 0.88 (0.56–1.39) | 742 | 0.62 (0.39–0.99)* | |
| High | 784 | 0.72 (0.43–1.19) | 784 | 0.57 (0.35–0.93)* | |
| Continuous | 2053 | 0.84 (0.67–1.04) | 1997 | 0.73 (0.57–0.94)* | |
| Physical workload | |||||
| Category | |||||
| Low | 1268 | 1 (reference) | 1300 | 1 (reference) | |
| Middle | 517 | 1.11 (0.70–1.76) | 483 | 1.32 (0.83–2.10) | |
| High | 318 | 0.99 (0.54–1.81) | 285 | 1.20 (0.64–2.26) | |
| Continuous | 2103 | 1.04 (0.80–1.34) | 2068 | 1.13 (0.85–1.49) | |
| Working with arms raised to or above shoulder level | |||||
| Category | |||||
| Low | 1399 | 1 (reference) | 1553 | 1 (reference) | |
| Middle | 486 | 1.38 (0.88–2.15) | 407 | 1.24 (0.78–2.00) | |
| High | 247 | 0.99 (0.53–1.86) | 160 | 0.98 (0.47–2.04) | |
| Continuous | 2132 | 1.06 (0.83–1.36) | 2120 | 1.12 (0.84–1.49) | |
aAge, sex, skill level, and baseline WAI adjusted for in all analyses.
bExposure averaged across time [(T1 + T2)/2].
*P < 0.01.
**P < 0.0006; Bonferroni-corrected significance level (0.01/16).
CI, confidence interval; OR, odds ratio; WAI, work ability index.