Table A1.

Participants in the study.

Characteristic		N	%
Gender	Woman	123	97.61
	Man	3	2.38
	All	126	100.00
Age	20–30 years old	28	22.22
	31–40 years old	25	19.84
	41–50 years old	61	48.41
	51–60 years old	12	9.52
	All	126	100.00
Work internship in the profession	0–10 years	39	30.95
	11–20 years	23	18.25
	21–30 years	53	42.06
	31–40 years	11	8.73
	All	126	100.00
Work experience in a shift system	0–10 years	39	30.95
	11–20 years	30	23.80
	21–30 years	45	35.71
	31–40 years	12	9.52
	All	126	100.00
Number of night shifts per month	3–4 duty	19	15.07
	5–6 duty	68	53.96
	7–8 duty	27	21.42
	More than 8 duties	12	9.52
	All	126	100.00