Table 3.

Decomposition analysis of the contribution of socio-demographic factors to economic inequalities in unprotected sex

Variables	Coefficient	95% CI	Contribution (%)
Prevalence in high-income group	0.152	0.640, 0.150*
Prevalence in low-income group	0.402	0.162, 0.310*
Differences	0.250	0.180, 0.033*	100.00
Differences in characteristics	0.123	0.082, -0.153	47.00
Age	0.001	-0.005, 0.005	-0.12
Educational level	0.019	0.002, 0.036	6.42
Marital status	0.008	0.700, -2.300	2.29
Age of first unprotected sex	-0.003	-0.007, 0.001	-1.04
Knowledge of partner’s HIV status	-0.004	-0.012, 0.004	-0.54
Dropping out of school	<0.001	-0.005, 0.005	0.90
Age of first drug use	0.003	-0.007, 0.014	1.34
Age of first injection	-0.001	-0.009, 0.006	0.54
History of incarceration	-0.005	-0.020, 0.010	-2.95
Access to harm reduction programs	0.055	0.032, 0.078	21.40
HIV⁄AIDS knowledge	0.040	0.023, 0.058	13.56
Methamphetamine use	0.018	0.007, 0.029	7.50
HIV testing	-0.001	-0.003, 0.001	-0.22
Due to difference in coefficients (odds ratios)	0.134	0.068, 0.201	53.00
Age	0.006	-0.007, 0.019	2.36
Educational level	-0.001	-0.011, 0.010*	-0.21
Marital status	0.003	-0.019, 0.025	1.20
Dropping out of school	0.002	-0.012, 0.017	0.87
Age of first drug use	0.220	-0.019, 0.063	8.43
Age of first injection	-0.001	-0.011, 0.010	0.21
Age of first unprotected sex	-0.013	-0.041, 0.015	-5.20
Access to harm reduction programs	-0.067	-0.215, 0.081	-26.60
HIV⁄AIDS knowledge	-0.040	-0.243, 0.145	-18.89
Knowing partner’s HIV status	0.110	-0.036, 0.256	-42.70
Methamphetamine use	-0.104	-0.224, 0.016	-40.35
History of incarceration	-0.001	-0.011, 0.010	0.23
HIV testing	0.011	-0.082, 0.105	4.37
Constant	0.70	0.01, 1.50	75.70

CI, confidence interval; HIV, human immunodeficiency virus; AIDS, acquired immune deficiency syndrome.

^*p<0.05.