Table 1.

Sociodemographic characteristics of the students according to N₂O use; comparisons between N₂O users and non-users were made by bivariate test (chi-square) and multivariate test (multivariate logistic regression). (§) not in the final model after stepwise multiple logistic regression.

Variable	Never Used N2O		N2O Users		Bivariate Test	Multivariate Test
	n	%	n	%	p-Value	p-Value (OR)
Gender					0.04	0.89 (§)
Males	34	24.5	152	33.5
Females	105	75.5	302	66.5
Type of sudies					0.0001	0.31 (§)
Midwifery	19	13.7	48	10.6
Medicine	25	18.0	154	33.9
Odontology	39	28.1	141	31.1
Pharmacy	56	40.3	111	24.4
Age					0.0001	0.64 (§)
<21 yr	79	56.8	95	20.9
21–22 yr	34	24.5	124	27.3
23–24 yr	19	13.7	135	29.8
>24 yr	7	5.0	100	22.0
Years of study					0.0001	0.0001 (3.46)
1–2 yr	65	46.8	54	11.9
3–4 yr	51	36.7	155	34.1
3–4 yr	23	16.6	245	53.9
Ever repeated year					0.16	0.07 (0.61)
No	46	33.1	180	39.7
Yes	93	66.9	274	60.3
Member of a students’ corporation					0.0001	0.002 (10.43)
No	137	98.6	345	76.0
Yes	2	1.4	109	24.0