Travel abroad increases sexual health risk-taking among Swedish youth: a population-based study using a case-crossover strategy

Figures & data

Table 1. Distribution of socio-demographic and background characteristics, including lifestyle and sexual risk-taking, among youth in Sweden who had travelled abroad during the last 12 months (n = 2189).

	Sweden = 12 months
	All		Men		Women
	n	%	n	%	n	%
Gender
Number	2189		897	41	1292	59
Age
18–24 years of age	1260	58	509	57	751	59
25–29 years of age	913	42	381	43	532	41
(Missing)	(16)		(7)		(9)
Level of parents’ education
University	1361	63	547	61	814	63
Less than university	814	37	344	39	470	37
(Missing)	(14)		(6)		(8)
Parents’ country of origin
Both parents born in Sweden	1620	74	650	73	970	75
At least one parent
born abroad	560	26	241	27	319	25
(Missing)	(9)		(6)		(3)
Self-rated mental health
Satisfactory mental health	1162	53	597	67	565	44
Poor mental health	1023	47	297	33	726	56
(Missing)	(4)		(3)		(1)
							Last trip abroad = 12 months
							All		Male		Female
							n	%	n	%	n	%
Duration of most recent travel
1–8 days							1448	67	581	66	867	68
9–29 days							488	23	209	24	279	22
1–6 months							167	8	67	8	100	8
= 6 months							53	2	18	2	35	2
(Missing)							(33)		(22)		(11)
Relation to the last sexual partner
Regular partner	1517	70	549	62	968	76	678	75	245	69	433	80
Casual partner	639	30	332	38	307	24	222	25	112	31	110	20
(Missing)	(33)		(16)		(17)		(0)		(0)		(0)
Heavy episodic drinking (HED)
Non-HED	932	46	306	36	626	52	926	46	317	38	609	51
HED	1115	54	541	64	574	48	1100	54	518	62	582	49
(Missing)	(142)		(50)		(92)		(163)		(62)		(101)
Use of illicit drugs
No	1918	88	737	83	1181	92	2016	94	791	90	1225	96
Yes	263	12	154	17	109	8	139	6	87	10	52	4
(Missing)	(8)		(6)		(2)		(34)		(19)		(15)

Table 2. Men (n = 897). Crude and adjusted* associations (odds ratio [OR], 95% confidence interval [CI]) for men whose last sex partner in Sweden during the past year was casual (n = 332) and men whose last sex partner abroad during the past year was casual (n = 112) in relation to age, parents’ country of origin, duration of travel, heavy episodic drinking (HED), use of illicit drugs, and self-rated mental health.

	Men who have had casual sex partner in Sweden						Men who have had casual sex partner abroad
	Crude			Adjusted			Crude			Adjusted
	OR	CI	(m)	OR	CI	(m)	OR	CI	(m)	OR	CI	(m)
Age			(23)			(79)			(5)			(29)
25–29 years	Ref. 1			Ref. 1			Ref. 1			Ref. 1
18–24 years	2.42	1.81–3.23		2.45	1.8–3.33		2.08	1.31–3.30		2.40	1.43–4.02
Parents’ country of origin			(22)						(3)
Both parents born
in Sweden	Ref. 1			Ref. 1			Ref. 1			Ref. 1
At least one parent born abroad	1.26	0.93–1.71		1.36	0.96–1.93		1.89	1.16–3.08		1.49	0.83–2.67
Duration of most recent travel									(5)
Long-time travel							2.69	1.51–4.80		2.32	1.18–4.56
Short-time travel							Ref. 1			Ref. 1
Heavy episodic drinking			(65)						(17)
Non-HED	Ref. 1			Ref. 1			Ref. 1			Ref. 1
HED	2.13	1.56–2.90		1.96	1.42–2.72		2.52	1.46–4.35		2.23	1.25–3.98
Use of illicit drugs			(21)						(3)
No	Ref. 1			Ref. 1			Ref. 1			Ref. 1
Yes	2.39	1.67–3.40		1.92	1.3–2.83		3.71	1.87–7.35		2.38	1.10–5.16
Self-rated mental health			(19)						(1)
Satisfactory mental health	Ref. 1			Ref. 1			Ref. 1			Ref. 1
Poor mental health	1.59	1.15–2.12		1.49	1.09–2.05		1.30	0.81–2.1		1.41	0.81–2.44

Notes: *All variables are simultaneously adjusted for one another.

(m) = missing.

Table 3. Women (n = 1292). Crude and adjusted* associations (odds ratio [OR], 95% confidence interval [CI]) for women whose last sex partner in Sweden during the past year was casual (n = 307) and women whose last sex partner abroad during the past year was casual (n = 110) in relation to age, parents’ country of origin, duration of travel, heavy episodic drinking (HED), illicit use of drugs, and self-rated mental health.

	Women who have had casual sex partner in Sweden						Women who have had casual sex partner abroad
	OR	CI	(m)	OR	CI	(m)	OR	CI	(m)	OR	CI	(m)
	Crude			Adjusted			Crude			Adjusted
Age			(26)			(117)			(6)			(55)
25–29 years	Ref. 1			Ref. 1			Ref. 1			Ref. 1
18–24 years	2.15	1.63–2.84		2.42	1.81–2.59		3.14	1.95–5.05		2.99	1.75–5.10
Parents’ country of origin			(20)						(1)
Both parents born in Sweden	Ref. 1			Ref. 1			Ref. 1			Ref. 1
At least one parent born abroad	0.83	0.61–1.12		0.87	0.62–1.22		0.78	0.47–1.29		1.04	0.58–1.87
Duration of most recent travel									(2)
Long-time travel							2.73	1.64–4.55		1.87	1.01–3.45
Short-time travel							Ref. 1			Ref. 1
Heavy episodic drinking			(106)						(44)
Non-HED	Ref. 1			Ref. 1			Ref. 1			Ref. 1
HED	3.17	2.40–4.19		2.71	2.03–3.62		3.78	2.27–6.30		3.31	1.91–5.72
Use of illicit drugs			(19)						(4)
No	Ref. 1			Ref. 1			Ref. 1			Ref. 1
Yes	3.19	2.14–4.78		2.11	1.37–3.25		5.19	2.55–10.5		4.81	2.14–10.8
Self-rated mental health			(18)						(1)
Satisfactory mental health	Ref. 1			Ref. 1			Ref. 1			Ref. 1
Poor mental health	1.33	1.02–1.73		1.15	0.88–1.53		1.38	0.9–2.12		1.19	0.73–1.94

Notes: *All variables are simultaneously adjusted for one another.

(m) = missing.

Table 4. Incidence Rate Ratios (IRR) of casual sex partner in a sample of Swedish youth (n = 2189, missing n = 33) who reported that they had travelled abroad during the past year. A modified case-crossover analysis of events of casual sex in Sweden and abroad in relation to median days spent in Sweden and median days in last travel abroad, during the last 12 months (95% confidence interval [CI], two-tailed p-value).

		Median days in Sweden/abroad^1		Individuals who have had a casual sex partner
	Total number of individuals	Sweden	Abroad	Sweden	(m)^2	Abroad	(m)	IRR	(CI)	p
Total	2156	738,583	48,357	626	(13)	221	(1)	5.37	(4.61–6.26)	< 0.001
Men	875	300,604	18,771	320	(12)	111	(1)	5.53	(4.46–6.86)	< 0.001
Women	1281	437,979	29,586	306	(1)	110		5.31	(4.27–6.6)	< 0.001
Data regarding number of days spent in Sweden and abroad	1448	360	5	412		110		18.9	(15.4–23.4)	< 0.001
	488	346	19	126		52		7.45	(5.41–10.3)	< 0.001
	167	260	105	69		43		1.54	(1.05–2.26)	< 0.036
	53	95	270	19		16		0.3	(0.15–0.58)	< 0.001

Notes: ¹1–8 days (median time 5 days), 9–29 days (median time 19 days), 1–6 months (median time 105 days), and more than 6 months (median time 270 days). The median days spent in Sweden are consequently: 360 days, 346 days, 260 days, and 95 days.

²(m) = Missing.