Rates of switching to second-line antiretroviral therapy and impact of delayed switching on immunologic, virologic, and mortality outcomes among HIV-infected adults with virologic failure in Rakai, Uganda

Table 3 Risk factors associated with delay in switching to second-line ART among HIV infected adults failing on first line ART

Exposure of time to second-line ART	n/ pys	n /100 pys	Univariate analysis		Multivariate Analysis
Exposure of time to second-line ART	n/ pys	(95% CI)	HRs (95% CI)	p-value	HRs (95% CI)	p-value
Risk of Immunologic decline associated with time to switch to second-line ART^a
Overall	30/259.0	11.6(8.1–16.6)
Time to 2nd line ART
0–6 months	6/108.7	5.5(2.5–12.3)	Ref		Ref
7–12 month	7/51.6	13.6(6.5–28.5)	2.75(0.6–12.1)	0.179	2.21(0.4–13.7)	0.389
13–24 month	10/62.6	16.0(8.6–29.7)	2.51(0.6–10.1)	0.193	2.76(0.6–13.7)	0.212
≥ 25 months	7/36.1	19.4(9.2–40.7)	4.09(1.0–16.9)	0.052	5.11(1.0–25.2)	0.045
Risk of virologic increase associated with time to switch to second-line ART^b
Overall	24/270.1	8.9(6.0–13.3)
Time to 2nd line ART
0–6 months	4/107.7	3.7(1.4–9.9)	Ref		Ref
7–12 month	1/75.8	1.3(0.2–9.4)	0.45(0.0–5.3)	0.52	0.32(0.0–3.6)	0.357
13–24 month	9/59.1	15.2(7.9–29.3)	10.40(2.0–52.9)	0.005	10.16(1.9–53.0)	0.006
≥ 25 months	10/27.4	36.5(19.6–67.8)	14.24(2.8–72.2)	0.002	10.13(1.7–59.3)	0.011
Risk of composite end-point associated with time to switch to second-line ART^c
Overall	43/212.8	20.2(15.0–27.2)
Time to 2nd line ART
0–6 months	10/96.3	10.4(5.6–19.3)	Ref		Ref
7–12 month	7/51.2	13.7(6.5–28.7)	1.48(0.4–5.8)	0.571	1.06(0.3–3.9)	0.928
13–24 month	15/41.3	36.4(21.9–60.3)	5.27(1.4–19.2)	0.012	5.05(1.5–16.9)	0.009
≥ 25 months	11/24.0	45.8(25.3–82.6)	4.94(1.4–17.1)	0.012	5.58(1.9–16.7)	0.003

Confounders considered for adjusting models a,b and c included: Age, Gender, characteristics at time of ART initiation: type of ART clinic, year of ART initiation, WHO stage (I, II, III/IV.), CD4 count (<100 or ≥100 cells/ul); characteristics at time of VF: CD4 count (<100 or ≥100 cells/ul), viral load (≤5000, 5001–10,000 or >10,000 copies/ml), year of VF and status of virologic failure prior to VF
EFV Efavirenz, NVP Nevirapine, n Number switched to 2nd line, pys Person years of observation, virologic failure Incident first line ART failure, HRs Hazard Ratios
^aCox proportional MSM model of the time to event of immunologic decline defined as decrease in CD4 count ≥50 cells/ul above CD4 count at virologic failure
^bCox proportional MSM model of the time to event of virologic increase defined as increase in viral load ≥0.5 log 10 copies/ml above viral load at virologic failure
^cCox proportional MSM model of the time to event of composite endpoint defined as reaching immunologic decline or virologic increase as defined in a and b above, or dying

ISSN: 1471-2334