Table 1

Sociodemographic characteristics of study participants

Characteristics	Categories	(n=10 289)	(%)
Gender	Boys	4567	44.3
Gender	Girls	5722	55.6
Age (years)	12–13	960	9.3
	14– 15	2776	26.9
	16– 17	3812	37.0
	18– 19	2221	21.5
	20	525	5.1
Class	Grade 7	1507	14.6
	Grade 8	2041	19.8
	Grade 9	2215	21.5
	Grade 10	1509	14.6
	Grade 11	1592	15.4
	Grade 12	1425	13.8
School type	UBS	5785	56.2
School type	SSS	4504	43.7
School ownership	Public	7678	74.6
	Grant-aided	1052	10.5
	Private	1559	15.1
Religion	Muslim	9564	93.1
	Christian	602	5.8
	Other	103	1.0
Daily school money	Do not have spending money	1435	13.9
	<D15	4131	40.2
	D16−D35	3205	31.2
	>D35	1497	14.5
Living with parents	Yes	8250	80.2
Living with parents	No	2029	19.7
Parents working	Father/stepfather/ male guardian only	3343	32.5
	Mother/stepmother/ female guardian only	1507	14.6
	Both	4300	41.8
	Neither	737	7.1
	Do not know	387	3.7
Home smoking allowed	No	7295	70.9
	Sometimes	1085	10.5
	Yes	1906	18.5
Family members who smoke	None	7364	71.6
	Mother	274	2.6
	Father	1199	11.6
	Brother/Sister	718	6.9
	Others	729	7.0
Number of friends who smoke	None	6790	66.0
	1	673	6.5
	2	356	3.4
	≥3	762	7.4
	Not sure	1699	16.5