Table 2.

Multivariate relative hazard (RH) associated with the first HAART switching that occurred within 5.5 years after HAART initiation using Cox proportional hazards models with time dependent covariates stratified by the calendar time of HAART initiation

	1996-2001			2002-2005			2006-2009
	RH	95% CI	p- value	RH	95% CI	p- value	RH	95% CI	p-value
Detectable HIV RNA*	1.87	1.44-2.44	<0.001	1.94	1.26-2.99	0.003	3.03	1.46-6.30	0.003
CNS symptoms*	NA			1.66	1.12-2.45	0.012	1.00	0.51-1.94	0.997
NNRTI-basedvs. PI based HAART regimen	0.75	0.54-1.04	0.081	0.96	0.63-1.47	0.849	0.59	0.30-1.16	0.126
Adherence* <95%	1.87	1.30-2.68	0.001	1.06	0.59-1.93	0.840	2.16	0.83-5.65	0.116
Age at HAART initiation, per 1 year	1.03	1.01-1.05	0.001	0.97	0.95-0.99	0.011	1.04	1.00-1.08	0.055

^*Measured at each visit prior to switching for persons who switched from their 1st HAART regimen within 5.5 years after HAART initiation, or prior to the last visit seen within 5.5 years after initiation for persons who did not switch HAART regimens within 5.5 years.

Other factors examined in the multivariate model but not show in table 2 due to having p>0.1 in all three time periods included ART-naïve before HAART, GI symptoms, hyperglycemia, hyperlipidemia, lipodystrophy, stopped HAART for at least 2 days in a row in the past 6 months, race, education and history of intravenous drug use.