Table 2. Factors associated with primary HIV drug resistance by duration of HIV infection - univariate logistic regression.

Variables	Recent HIV infection			Chronic HIV infection
	Odds ratio	95% Confidence interval	p-value*	Odds ratio	95% Confidence interval	p-value*
Age groups, years			0.054			0.112
≤30	1			1
31–40	3.64	1.44–9.20	0.006	0.63	0.33–1.21	0.168
41–50	1.41	0.18–11.29	0.746	0.55	0.25–1.18	0.125
≥51	6.58	0.65–66.25	0.110	0.44	0.15–1.34	0.151
Gender
Female	1			1
Male	2.47	0.32–18.69	0.382	1.24	0.68–2.25	0.480
Ethnicity
Non Thai	1			1
Thai	0.74	0.34–1.60	0.439	0.76	0.43–1.34	0.345
Exposure
Non-heterosexual	1			1
Heterosexual contact	0.49	0.11–2.13	0.344	0.34	0.20–0.59	<0.001
CDC category *						0.589
A				1
B				1.21	0.57–2.57	0.623
C				0.85	0.46–1.57	0.613
Subtype
Non CRF01_AE	1			1
CRF01_AE	0.68	0.31–1.50	0.344	0.57	0.32–1.03	0.064
CD4, cells/mm3			0.394			0.824
≤200	1			1
≥201	2.54	0.33–19.74	0.373	0.86	0.49–1.66	0.663
Missing	3.06	0.45–28.50	0.225	0.62	0.08–4.59	0.636
HIV RNA, copies/mL			0.560			0.508
≤50,000	1			1
50,001–250,000	0.28	0.06–1.30	0.105	0.75	0.40–1.41	0.377
≥250,001	1.86	0.66–5.26	0.243	0.80	0.38–1.68	0.551
Missing	2.03	0.81–5.11	0.131	2.00	0.24–16.53	0.518
HBsAg serostatus *						0.226
Negative				1
Positive				1.88	0.89–3.98	0.096
Missing				0.90	0.35–2.32	0.827
Anti-HCV serostatus *						0.473
Negative				1
Positive				1.10	0.38–3.15	0.856
Missing				0.63	0.29–1.36	0.238

Abbreviations: HBsAg – hepatitis B surface antigen, anti-HCV – antibody to hepatitis C virus.

^*p-value is for test for trend (excluding missing values) for age groups, CDC category, and HIV RNA.