Table 5. Univariate and multivariable logistic regression analysis of factors associated with virological failure at 48 weeks.

		Univariate analysis			Multivariable analysis
		N	Failure (%)	p-value	AOR	95% CI	p-value
Age (years)	<35	105	28.6	0.19	1.00		0.05
	≥35	897	19.1		0.58a	0.35–0.95
	35–44	354	20.0
	45–54	379	19.3
	≥55	164	16.5
Nadir CD4 count (cells/mm3)	<50	195	29.7	<0.01	1.00
	50–199	335	17.9		0.55	0.35–0.85	<0.01
	200–349	209	16.3		0.57	0.34–0.94	0.03
	≥350	112	14.3		0.42	0.22–0.81	<0.01
Baseline CD4 count (cells/mm3)	<50	31	32.3	<0.01	NI
	50–199	170	27.6
	200–349	196	20.4
	≥350	584	16.6
Baseline HIV-1 RNA (cps/mL)	<50	473	10.1	<0.01	1.00
	50–199	110	30.9		3.59	2.13–6.03	<0.01
	200–4.999	182	32.4		4.45	2.83–6.98	<0.01
	5.000–99.999	141	18.6		2.37	1.39–4.03	<0.01
	≥100.000	81	32.9		4.88	2.74–8.69	<0.01
Maraviroc daily dose	<300 mg	105	21.9	0.33	NI
	≥300 mg	752	19.3
Maraviroc schedule	Once daily	190	21.6	0.52	NI
	Twice daily	498	18.5
Context of maraviroc use	ART naive	32	15.6	<0.01	NI
	Switch. suppressed VL	303	8.6
	Switch. detectable VL	310	27.7
	Intensify. suppressed VL	34	14.7
	Intensify. detectable VL	37	40.5
Drug classes previously experienced	<3	361	17.2	0.13
	3	337	19.9
	≥3	311	23.5
Previous PI experience	Yes	876	21.0	0.05	2.21	1.21–4.04	0.01
	No	133	13.7
Previous INSTI experience	Yes	456	22.4	0.07	NI
	No	553	17.9
Previous enfuvirtide experience	Yes	61	26.2	0.18	NI
	No	948	19.5
Viral tropism	R5	805	19.8	0.06	1.00
	Non-R5	108	25.2		1.25	0.79–1.96	0.34
ART classes used with maraviroc (n)	1	378	15.9	0.02	NI
	2	457	21.0
	3	105	28.6
Concomitant PI use	Yes	655	21.3	0.17
	No	285	16.1
GSS of accompanying regimen	<1	73	17.8	<0.01	1.00
	1 <2	191	17.3		0.82	0.64–2.76	0.61
	2 <3	188	18.6		0.86	0.40–1.85	0.69
	≥3	65	33.8		2.14	0.90–5.09	0.08

Note: Table refers to 1009 subjects; cases with missing values for each variable are not reported in the table; in 264 cases viral tropism was collected but no FPR was available at the data analysis. Additional variables tested but not found to be associated by univariate analysis (p>0.2): maraviroc schedule and daily dosing, gender, ethnicity, number of previous drugs experienced, previous experience with NRTIs, or NNRTIs, viral subtype, false positive rate value of the geno2pheno[coreceptor] genotypic tropism interpretation, and calendar year of maraviroc start.

^a(≥ 35 vs <35 years)

All variables shown in the univariate analysis were included in the multivariable model. Variables retained in the final step of the backward elimination procedure (see methods) are shown. all the other were excluded, except the viral tropism result that was manually included. All AOR shown are simultaneously adjusted.