Table 1.

Demographic and Working Variables of Participants in Relation to CES-D Score

Variables	n	%	CES-D Score
Mean	SD	F/t	P-value
Age (years)
≤30	203	11.1	19.32	10.61	1.957	0.119
31–40	416	22.7	20.47	11.17
41–50	863	47.0	19.29	10.32
≥51	354	19.3	18.73	10.01
Gender
Men	1409	76.7	19.55	10.48	0.532	0.466
Women	427	23.3	19.13	10.57
Marital status
Married/cohabiting	1568	85.4	19.41	10.46	0.176	0.675
Single/divorced/widowed/separated	268	14.6	19.70	10.77
Education level
Senior high school or below  Technical secondary school or above	948 888	51.6 48.4	19.40	10.25	0.043	0.836
19.50	10.77
Monthly income (RMB)
<4000	1085	59.1	19.56	10.72	0.311	0.577
≥4000	751	40.9	19.29	10.18
Occupational category
Refinery workers	746	40.6	20.88a	10.96	10.751	<0.001
Chemical workers	283	15.4	19.75b	10.28
Transportation workers	355	19.3	18.72a	10.13
Other workers	452	24.6	17.48b	9.80
Night duty
Yes	1111	60.5	20.26	10.92	16.956	<0.001
No	725	39.5	18.21	9.690
Shift work
Yes	985	53.6	20.36	10.86	16.130	<0.001
No	851	46.4	18.40	9.97

Notes: ^abTukey’s test was used for post-hoc test, and the groups marked with different letters represent the statistical differences between the two comparisons. p<0.05.

Abbreviations: SD, standard deviation; CES-D score, score of depressive symptoms.