Table 3.
Crude, semi-adjusted, and fully adjusted models for night shift exposure and sickness absence outcomes
| Crude model | Semi-adjusted model | Fully adjusted model | ||
|---|---|---|---|---|
| Long-term sickness absence (>7 days) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
| Number of night shifts 2005–2008 | No night shifts | Reference | Reference | Reference |
| Night shifts (1 to ≤46) | 1.36 (1.20–1.53) | 1.30 (1.12–1.50) | 1.15 (0.99–1.34) | |
| Night shifts (47 ≤ 110) | 1.54 (1.36–1.74) | 1.17 (1.01–1.34) | 1.01 (0.87–1.17) | |
| Night shifts (>110) | 1.08 (0.95–1.22) | 1.06 (0.92–1.21) | 1.05 (0.91–1.21) | |
| Sickness absence days 2005–2008 | ≥0 to <26 days | Reference | Reference | |
| ≥26 to <67 days | 3.08 (2.60–3.65) | 2.99 (2.52–3.55) | ||
| ≥67 to <140 days | 8.11 (6.81–9.66) | 7.42 (6.21–8.86) | ||
| ≥140 days | 12.56 (10.50–15.02) | 11.23 (9.36–13.48) | ||
| Special operational requirements | 1.00 (0.98–1.02) | |||
| Knowledge requirements | 0.98 (0.97–0.98) | |||
| Aggravated working conditions | ≤4 | Reference | ||
| >4 to ≤11 | 1.16 (0.97–1.39) | |||
| >11 to ≤15 | 1.18 (0.96–1.45) | |||
| >15 | 1.26 (0.98–1.61) | |||
| Sickness absence episodes | IRR (95% CI) | IRR (95% CI) | IRR (95% CI) | |
| Number of night shifts 2005–2008 | No night shifts | Reference | Reference | Reference |
| Night shifts (1 to ≤46) | 1.03 (0.97–1.08) | 0.93 (0.88–0.98) | 0.97 (0.91–1.02) | |
| Night shifts (47 ≤ 110) | 0.99 (0.94–1.04) | 0.87 (0.83–0.92) | 0.91 (0.86–0.96) | |
| Night shifts (>110) | 0.94 (0.89–0.99) | 0.95 (0.90–1.00) | 0.93 (0.88–0.98) | |
| Sickness absence days 2005–2008 | ≥0 to <26 days | Reference | Reference | |
| ≥26 to <67 days | 2.19 (2.05–2.34) | 2.21 (2.06–2.35) | ||
| ≥67 to <140 days | 3.16 (2.95–3.38) | 3.20 (2.99–3.43) | ||
| ≥140 days | 3.49 (3.27–3.73) | 3.56 (3.32–3.81) | ||
| Special operational requirements | 1.01 (1.00–1.02) | |||
| Knowledge requirements | 1.00 (0.99–1.00) | |||
| Aggravated working conditions | ≤4 | Reference | ||
| >4 to ≤11 | 1.03 (0.96–1.11) | |||
| >11 to ≤15 | 1.04 (0.96–1.13) | |||
| >15 | 0.87 (0.79–0.96) | |||
Semi-adjusted model adjusted for age, gender, marital status, having children, commuting distance, employment duration, mean contract percentage, working overtime, and previous sickness absence days. Job classification variables special operational requirements, knowledge requirements, and aggravated working conditions were added to the fully adjusted model
Bold: P < 0.05