COITAL EXPERIENCE AMONG ADOLESCENTS IN THREE SOCIAL-EDUCATIONAL GROUPS IN URBAN CHIANG MAI, THAILAND

Figures & data

TABLE 1  Socio-economic background characteristics of social-educational groups.

	Social-educational group
	Out-of-school		Vocational school		General school/university
Socio-economic index	Males	Females	Males	Females	Males	Females
Parents’ monthly income
< 10,000 baht	51.0	52.9	51.8	56.4	24.9	22.4
10,000–24,999 baht	31.8	31.1	30.8	25.0	28.6	31.3
25,000–49,999 baht	9.9	9.4	13.7	9.9	24.9	25.6
50,000 baht or more	7.3	6.6	3.7	8.7	21.6	20.7
Total	100.0	100.0	100.0	100.0	100.0	100.0
Missing cases (%)	19.3	37.3	14.9	19.3	8.0	7.4
Father's education
None	12.7	32.3	4.8	2.9	1.6	1.8
Primary	48.0	39.1	53.9	64.2	25.3	24.4
Lower secondary	14.9	8.9	15.8	11.8	11.3	11.9
Upper secondary	11.8	12.7	12.5	8.8	14.0	15.4
College or university	12.6	7.0	13.0	12.3	47.8	46.5
Total	100.0	100.0	100.0	100.0	100.0	100.0
Missing cases (%)	7.1	6.5	4.6	4.2	1.9	2.6
Father's occupation
Unskilled	48.7	38.2	22.9	40.4	6.6	12.6
Semi-skilled	45.6	60.5	68.6	54.1	67.3	57.8
Skilled	5.7	1.3	8.5	5.5	26.1	29.7
Total	100.0	100.0	100.0	100.0	100.0	100.0
Missing cases (%)	4.2	10.1	8.1	13.7	1.9	3.0

TABLE 2  Sexual experience of adolescents by sex and social-educational group.

Sex and social-educational group	Ever had sexual contact or sexual intercourse?								Standardised% had sexual intercourse**
	Never had either		Had sexual contact only		Had sexual intercourse*		Total
	No.	%	No.	%	No.	%	No.	%
Males
Out-of-school	45	18.9	0	0.0	193	81.1	238	100	79.2
Vocational school	116	28.6	11	2.7	279	68.7	406	100	66.0
General school or university	163	62.2	6	2.3	93	35.5	262	100	37.4
Total	324	35.8	17	1.9	565	62.4	906	100	62.4
Females
Out-of-school	76	45.0	4	2.4	89	52.7	169	100	49.3
Vocational school	73	34.6	6	2.8	132	62.6	211	100	62.5
General school or university	382	83.2	9	2.0	68	14.8	459	100	15.2
Total	531	63.3	19	2.3	289	34.4	839	100	34.4
*All pairs of percentages for social-educational groups for a given sex, and male/female percentages for each social-educational group, are significantly different (p<0.001), except for the male/female vocational school and female out-of-school/vocational school comparisons, which are not significantly different (p>0.05).
**Standardised to age distribution of total males or total females as appropriate.

TABLE 3  Crude odds ratios for variables associated with having ever had sexual intercourse by sex.

	Male (n = 909)			Female (n = 840)
Independent variable	n	% ever had sexual intercourse	Crude odds ratios (95% CI)	n	% ever had sexual intercourse	Crude odds ratios (95% CI)
Age
17	85	28.2	1	136	11.8	1
18	301	62.8	4.29 (2.53–7.27)***	304	40.8	5.17 (2.92–9.13)***
19	364	65.9	4.92 (2.93–8.27)***	300	37.3	4.47 (2.52–7.91)***
20	156	71.8	6.47 (3.60–11.64)***	99	37.4	4.48 (2.31–8.68)***
Social-educational background
General school or university	262	35.5	1	459	14.8	1
Vocational school	406	68.7	3.99 (2.87–5.55)***	211	62.6	9.61 (6.57–14.04)***
Out-of-school	238	81.1	7.79 (5.17–11.76)***	169	52.7	6.40 (4.30–9.51)***
Religion
Buddhism	838	63.6	1	754	36.1	1
Christianity	53	45.3	0.47 (0.27–0.83)**	74	17.6	0.38 (0.20–0.70)**
Islam	12	50.0	0.57 (0.18–1.79)	6	16.7	0.35 (0.04–3.05)
Living situation
Live with parent(s) or relatives	558	63.1	1	408	29.0	1
Live with other family	21	47.6	0.53 (0.22–1.27)	48	50.0	2.45 (1.35–4.47)**
Live with friends	235	59.6	0.86 (0.63–1.18)	239	33.9	1.26 (0.90–1.75)
Live alone	91	69.2	1.32 (0.82–2.12)	70	62.9	4.15 (2.46–7.01)***
Parents’ monthly income
25,000 baht or more	205	51.7	1	246	19.1	1
Less than 25,000 baht	576	66.0	1.81 (1.31–2.50)***	456	40.4	2.86 (1.98–4.14)***
Father's highest education
College or university	201	52.2	1	244	22.5	1
Secondary school or lower	667	64.3	1.64 (1.20–2.27)**	564	38.5	2.15 (1.52–3.34)***
Mother's highest education
College or university	173	48.6	1	207	20.8	1
Secondary school or lower	702	64.4	1.92 (1.37–2.70)***	617	37.9	2.33 (1.61–3.38)***
Father's occupation
Skilled	112	52.7	1	144	13.9	1
Semi-skilled	535	59.8	1.34 (0.89–2.01)	448	31.0	2.79 (1.67–4.66)***
Unskilled	214	74.3	2.60 (1.61–4.20)***	188	50.5	6.33 (3.65–11.00)***
Mother's occupation
Skilled	69	58.0	1	107	17.8	1
Semi-skilled	463	59.4	1.06 (0.64–1.77)	431	30.6	2.05 (1.20–3.50)**
Unskilled	341	66.3	1.43 (0.84–2.42)	261	44.1	3.65 (2.10–6.34)***
Parents’ marital status
Married	636	57.5	1	630	30.6	1
Divorced	145	74.5	2.15 (1.44–3.23)***	102	45.1	1.86 (1.22–2.85)**
One or both dead	125	72.8	1.97 (1.29–3.02)**	107	46.7	1.99 (1.31–3.01)**
Quality of parental relationship growing up
Parents never or sometimes quarrelled	776	59.4	1	717	30.7	1
Parents quarrelled quite often	67	77.6	2.37 (1.31–4.28)**	61	55.7	2.85 (1.68–4.83)***
Race/ethnicity of family
Northern Thai	569	70.5	1	466	42.3	1
Thai—another region	116	55.2	0.52 (0.34–0.78)**	97	30.9	0.61 (0.38–0.98)*
Chinese	101	41.6	0.30 (0.19–0.46)***	107	24.3	0.44 (0.27–0.71)**
Hill Tribes	36	50.0	0.42 (0.21–0.83)*	58	13.8	0.22 (0.10–0.47)***
Other race	16	50.0	0.42 (0.16–1.04)	30	46.7	1.20 (0.57–2.51)
Mixed race	67	46.3	0.36 (0.22–0.60)***	81	17.3	0.29 (0.16–0.52)***
Ever drunk alcohol in past year?
No	167	24.0	1	372	14.0	1
Yes	735	71.2	7.83 (5.31–11.56)***	466	50.6	6.31 (4.47–8.91)***
Ever smoked in past year?
No	493	45.2	1	715	27.0	1
Yes	408	83.3	6.05 (4.42–8.30)***	120	77.5	9.32 (5.89–14.75)***
Ever taken methamphetamines in past year?
No	756	56.1	1	795	31.7	1
Yes	142	94.4	13.12 (6.34–27.15)***	40	82.5	10.16 (4.34–23.28)***
Ever used marijuana in past year?
No	763	57.7	1	820	33.3	1
Yes	135	87.4	5.10 (3.00–8.64)***	13	92.3	24.04 (3.11–185.87)***
*p < 0.05; **p < 0.01; ***p < 0.001.

TABLE 4  Logistic regression analysis of variables associated with males having ever had sexual intercourse.

	Model I	Model II
Independent variable	Adjusted odds ratio (95% CI)	Adjusted odds ratio (95% CI)
Age
17	1	1
18	2.69 (1.30–5.57)*	2.65 (1.40–5.00)**
19	2.79 (1.36–5.72)*	2.57 (1.35–4.87)**
20	4.03 (1.75–9.25)**	3.93 (1.89–8.19)***
Social-educational background
General school or university	1	1
Vocational school	1.91 (1.23–2.95)*	1.69 (1.11–2.53)**
Out-of-school	3.26 (1.76–6.03)***	2.29 (1.35–3.87)**
Parents’ marital status
Married	1	1
Divorced	1.34 (0.73–2.47)	1.87 (1.16–3.03)**
One or both dead	2.26 (1.14–4.51)*	1.67 (1.00–2.80)
Race/ethnicity of family
Northern Thai	^#	1
Thai—another region		0.66 (0.40–1.08)
Chinese		0.60 (0.34–1.03)
Hill Tribes		0.35 (0.16–0.76)*
Other race		0.55 (0.18–1.70)
Mixed race		0.47 (0.25–0.90)*
Ever drunk alcohol in past year?
No	1	1
Yes	3.61 (2.19–5.93)***	3.78 (2.42–5.91)***
Ever smoked in past year?
No	1	1
Yes	2.56 (1.66–3.92)***	2.50 (1.71–3.66)***
Ever taken methamphetamines in past year?
No	1	1
Yes	4.42 (1.87–10.48)**	5.22 (2.34–11.67)***
*p < 0.05; **p < 0.01; ***p < 0.001.
#Not significant in Model 1; became significant in Model II after addition of cases missing on parental variables not significant in Model I.
Model I: includes all variables significant in bivariate setting that remained significant after stepwise regression; missing cases = 225/909.
Model II: repeats Model I after eliminating non-significant parental variables that were sources of missing cases (parents’ income, mother's/father's education, father's occupation and quality of parental relationship when growing up); missing cases = 18/909.

TABLE 5  Logistic regression analysis of variables associated with females having ever had sexual intercourse.

	Model I	Model II
Independent variable	Adjusted odds ratio (95% CI)	Adjusted odds ratio (95% CI)
Social-educational background
General school or university	1	1
Vocational school	4.94 (2.90–8.43)***	4.79 (3.03–7.57)***
Out-of-school	4.71 (2.44–9.12)***	4.26 (2.43–7.48)***
Living situation
Live with parent(s) or relatives	1	1
Live with other family	2.56 (0.82–8.00)	2.56 (1.09–6.04)*
Live with friends	1.19 (0.72–1.96)	1.33 (0.85–2.08)
Live alone	3.08 (1.35–7.02)**	3.16 (1.59–6.29)**
Quality of parental relationship growing up
Parents never or sometimes quarrelled	1	1
Parents quarrelled quite often	3.91 (1.72–8.84)**	2.82 (1.46–5.46)**
Race/ethnicity of family
Northern Thai	1	1
Thai—another region	0.87 (0.43–1.75)	0.80 (0.44–1.46)
Chinese	0.66 (0.30–1.46)	0.67 (0.34–1.30)
Hill Tribes	0.26 (0.64–1.08)	0.17 (0.06–0.47)**
Other race	0.90 (0.22–3.65)	1.03 (0.36–2.99)
Mixed race	0.35 (0.15–0.85)*	0.34 (0.16–0.76)**
Ever drunk alcohol in past year?
No	1	1
Yes	3.98 (2.38–6.65)***	3.71 (2.39–5.75)***
Ever smoked in past year?
No	1	1
Yes	3.84 (1.97–7.51)***	3.49 (1.97–6.02)***
*p < 0.05; **p < 0.01; ***p < 0.001.
Model I: includes all variables significant in bivariate setting that remained significant after stepwise regression; missing cases = 243/840. Model II: repeats Model I after eliminating non-significant parental variables that were sources of missing cases (parents’ income, mother's/father's education and mother's/father's occupation); missing cases = 76/840.