Table 2.
Odds Ratios of Insomnia Among Permanent Employees, Direct-Hire Employees, and Temporary Work Agents (TWAs)
| Model 1 | Model 2 | |||||
|---|---|---|---|---|---|---|
| OR | 95% CI | Δχ2 | Adjusted OR | 95% CI | Δχ2 | |
| Block 1 | 1636.23*** | |||||
| Data collection period by season | ||||||
| Spring (Reference category) | 1.00 | |||||
| Summer | 1.28* | 1.05–1.55 | ||||
| Autumn | 1.26* | 1.02–1.56 | ||||
| Winter | 1.00 | 0.82–1.23 | ||||
| Demographic and lifestyle factors | ||||||
| Age | 0.99*** | 0.98–0.99 | ||||
| Sex (Reference group = male) | 1.19 | 1.09–1.29 | ||||
| Alcohol consumption | 1.19*** | 1.09–1.29 | ||||
| Cigarette smoke | 1.02*** | 1.01–1.02 | ||||
| Body mass index | 1.03 | 1.02–1.03 | ||||
| Number of diseases | 1.55*** | 1.49–1.61 | ||||
| Work-related factors | ||||||
| Job sectors | ||||||
| Manufacturing (Reference group) | 1.00 | |||||
| Real estate | 1.01 | 0.82–1.26 | ||||
| Retail and wholesales | 0.86 | 0.68–1.09 | ||||
| Agriculture | 0.64** | 0.48–0.87 | ||||
| Health care | 0.50 | 0.24–1.04 | ||||
| Public administration | 0.78* | 0.63–0.96 | ||||
| Finance | 0.90 | 0.71–1.13 | ||||
| Information technology | 1.15 | 0.95–1.38 | ||||
| Arts and entertainment | 1.35 | 0.42–4.30 | ||||
| Shift work (Reference = nonshift group) | 1.25*** | 1.16–1.35 | ||||
| Overtime work hours | ||||||
| Less than 15 hours (Reference group) | 1.00 | |||||
| 15 to 29 hours | 0.89** | 0.82–0.97 | ||||
| 30 to 44 hours | 0.84*** | 0.77–0.91 | ||||
| 45 to 59 hours | 0.86** | 0.78–0.96 | ||||
| 60 to 79 hours | 0.75*** | 0.66–0.86 | ||||
| 80 hours or more | 0.81* | 0.66–0.98 | ||||
| Block 2 | 924.75*** | 382.63*** | ||||
| Interpersonal conflict (IC) | 1.98*** | 1.89–2.07 | 1.63*** | 1.53–1.71 | ||
| Employment type (ET) | ||||||
| Permanent (Reference group) | 1.00 | 1.00 | ||||
| Direct-hire | 0.92 | 0.79–1.08 | 1.17 | 0.97–1.41 | ||
| TWA | 0.74 | 0.53–1.02 | 1.04 | 0.72–1.50 | ||
| Block 3 | 6.51* | 6.56* | ||||
| Workplace interpersonal conflict (WIC) | 1.96*** | 1.87–2.05 | 1.61*** | 1.53–1.69 | ||
| Employment type (ET) | ||||||
| Permanent (Reference group) | 1.00 | 1.00 | ||||
| Direct-hire | 0.92 | 0.78–1.08 | 1.16 | 0.97–1.40 | ||
| TWA | 0.73 | 0.52–1.02 | 1.03 | 0.70–1.50 | ||
| IC × ET interaction | ||||||
| C × Direct-hire | 1.14 | 0.89–1.46 | 1.11 | 0.86–1.43 | ||
| IC × TWA | 1.88* | 1.10–3.22 | 1.97* | 1.13–3.45 | ||
Note. OR = odds ratio; CI = confidence interval.
*
p < .05;
**
p < .01;
***
p < .001.