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

From: 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

Exposure of time to second-line ART n/ pys n /100 pys Univariate analysis Multivariate Analysis
(95% CI) HRs (95% CI) p-value HRs (95% CI) p-value
Risk of Immunologic decline associated with time to switch to second-line ARTa
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 ARTb
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 ARTc
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
  1. 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
  2. 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
  3. 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
  4. 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
  5. 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