Table 3.

Hazard Ratios for Virologic failure While on Second ART Regimen (ART-2). Of 5565 Patients Starting ART-2, 456 Experienced Virologic Failure During a Median of 2.9 Years of Follow-up.^*

	Unadjusted		Adjusted
	HR (95% CI)	P-value	HR (95% CI)	P-value
Male sex	0.94 (0.76–1.15)	0.53	0.87 (0.71–1.08)	0.21
Age (years)		<0.001		0.001
20	1.54 (1.01–2.36)		1.51 (0.98–2.32)
30	1.13 (0.95–1.35)		1.05 (0.88–1.27)
40 (ref)	1		1
50	0.75 (0.64–0.89)		0.80 (0.68–0.96)
AIDS at enrollment	1.13 (0.91–1.41)	0.27	1.02 (0.79–1.31)	0.87
Change in CD4 (ART-1 to ART-2) (cells/ul)		<0.001		<0.001
−50	1.16 (1.09–1.24)		1.12 (1.05–1.20)
0	1		1
100	0.72 (0.62–0.84)		0.75 (0.64–0.88)
200	0.54 (0.41–0.72)		0.57 (0.40–0.82)
300	0.43 (0.31–0.59)		0.48 (0.30–0.75)
CD4 at start of ART-2 (cells/uL)		<0.001		0.043
50	2.21 (1.66–2.93)		1.39 (0.96–2.01)
100	2.00 (1.49–2.70)		1.28 (0.90–1.83)
200	1.50 (1.23–1.83)		1.12 (0.89–1.41)
350 (ref)	1		1
Year of starting ART-2 (per year)**	0.93 (0.90–0.96)	<0.001	0.95 (0.92–0.99)	0.008
Months between start of ART-1 and ART-2**		0.024		0.16
3 (ref)	1		1
6	1.04 (0.98–1.12)		1.06 (0.98–1.14)
12	1.02 (0.92–1.13)		1.10 (0.97–1.25)
24	0.91 (0.80–1.05)		1.12 (0.93–1.36)
36	0.83 (0.70–1.00)		1.13 (0.88–1.44)
Reason for starting ART-2		<0.001		<0.001
Toxicity (ref)	1		1
Failure	2.28 (1.75–2.97)	<0.001	2.06 (1.52–2.79)	<0.001
Other	1.30 (1.05–1.61)	0.017	1.39 (1.09–1.77)	0.007
Unknown	1.10 (0.73–1.67)	0.65	1.06 (0.69–1.62)	0.80

^*All hazard ratios are adjusted for study site.

^**When year of starting ART-2 and months between start of ART-1 and ART-2 were replaced with year of starting ART-1, compared to the reference year of 2003, adjusted HR (95% CI) were 0.92 (0.86–0.98), 0.84 (0.74–0.96), and 0.77 (0.63–0.95) for starting ART-1 in the years 2005, 2007, and 2009, respectively.

Abbreviations: ART, antiretroviral therapy; CI, confidence interval; HR, hazard ratio; ref, reference value.