Table 2.

Multiple linear regression models of socioeconomic indicators and changes in the CES-D score (N = 2351)

Variables	Coefficient	Lower 95% CI	Upper 95% CI	P value
Non-permanent	0.135	−0.720	0.989	0.757
Unemployment experience	2.358	0.793	3.923	0.003	**
Non-permanent * Unemployment experience	−1.148	−3.507	1.210	0.340
Sex	−0.301	−1.055	0.452	0.433
Age	−0.015	−0.050	0.020	0.397
Number of comorbidities
0 (base)	1.000
1	0.939	−0.238	2.116	0.118
More than 2	3.284	0.092	6.476	0.044	*
High infection area	0.566	−0.125	1.256	0.108
Married	−0.821	−1.570	−0.072	0.032	*
Personal income
Low (base)	1.000
Middle	−0.078	−1.122	0.967	0.884
High	−0.551	−2.099	0.998	0.486
Family income
Low (base)	1.000
Middle	−0.465	−1.417	0.486	0.338
High	−1.003	−2.189	0.184	0.098
Average work time per day
Less than 8 h (base)	1.000
Between 8 and 10 h	−0.091	− 0.888	0.706	0.822
Between 10 and 12 h	1.574	0.179	2.969	0.027	*
Over 12 h	0.467	−2.210	3.145	0.732
Union membership	−0.194	−0.928	0.540	0.604
Householder	0.235	−0.617	1.087	0.589
Exercise
None (base)	1.000
Once every 2 weeks	0.531	−0.639	1.701	0.373
Once in a week	0.537	−0.472	1.545	0.297
More than 2 times in a week	−0.203	−1.126	0.719	0.665
Smoking
No (base)	1.000
Yes	−0.270	−1.151	0.611	0.548
Past	−0.338	−1.441	0.766	0.548
Drink
No (base)	1.000
Yes	−0.604	−1.306	0.097	0.091
Past	0.011	−1.527	1.549	0.989
Sleeping time
Less than 4 h	0.750	−1.381	2.880	0.490
Between 4 and 6 h	−0.052	− 0.838	0.735	0.898
Between 6 and 8 h (base)	1.000
Over 8 h	0.999	− 0.074	2.073	0.068
SOC score	−0.134	−0.172	− 0.097	< 0.001	***
Base-line CES-D score	−0.383	−0.420	− 0.347	< 0.001	***
Constant	14.721	11.913	17.528	< 0.001	***

CES-D Center for Epidemiologic Studies Depression Scale, SOC Sense of coherence

*: P < 0.05, **: P < 0.01, ***: P < 0.001