Table 1.

Socio-demographics, working conditions, MSDs and depression among nurses (n=397)

Variables	Mean±SD or Percentage
	Total	Comorbidity	Non-comorbidity
	(n=397)	(n=55)	(n=324)
Age	43.2±12.0	42.6±11.6	43.3±12.1
≤40y	42.0%	47.3%	41.0%
>40y	58.0%	52.7%	59.0%
Gender
Female	95.2%	98.2%	94.7%
Male	4.8%	1.8%	5.3%
Race
White	91.9%	89.1%	92.9%
Black	3.1%	1.8%	2.8%
Others	5.0%	9.1%	4.3%
Body Mass Index	26.8±6.0	27.2±6.8	26.6±5.8
Normal	44.4%	40.4%	45.3%
Overweight	31.9%	38.5%	31.0%
Obese	23.7%	21.2%	23.7%
Regular exercise (yes)	43.1%	37.0%	44.4%
Shift work
8-hour day	35.9%	29.1%	36.4%
8-hour evening	13.7%	5.5%	15.6%
8-hour night	6.9%	10.9%	6.5%
12-hour day	20.1%	30.9%	19.0%
12-hour evening	3.6%	3.6%	3.4%
12-hour night	19.8%	20.0%	19.0%
Physical demands (range 5–20)	13.4±3.3	14.1±3.3	13.3±3.3
Psychological demands (range 4–16)	11.4±1.8	11.7±1.9	11.3±1.8
Job control (range 3–12)	9.1±1.4	8.6±1.4**	9.2±1.4
Social support (range 4–16)	12.1±1.9	11.8±1.8	12.2±1.9
Work-family conflict (range 1–4)	2.5±0.6	2.8±0.6**	2.4±0.5

Note.

^*p<0.05

^**p<0.01.

Nurses mainly work permanent shifts at the study hospital. 12-hour evening includes work schedules of 9am-9pm, 11am-11pm, and 12pm-12am. 12-hour night includes work schedules of 7pm-7am and 3pm-3am.

Physical demands, psychological demands, job control, social support were measured with items from the Job Content Questionnaire (Karasek et al., 1998). Work-family conflict was measured with items from Kopelman et al. (1983). Depression was measured with the Center for Epidemiologic Studies Depression Scale, the 10-item version (Andresen et al., 1994).