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Table 3 Factors associated with severe anaemia (Hb <8.0 g/dL) using Multivariable Cox models by cohort and RCT arm

From: Maternal anaemia and duration of zidovudine in antiretroviral regimens for preventing mother-to-child transmission: a randomized trial in three African countries

  

Cohort 1

  

Cohort 2

  

RCT arms

  

Predictor

Anaemia failures/n

Unadjusted hazard ratio (HR)

Adjusted HR

P-valueii

Unadjusted HR

Adjusted HR

P-valueii

Unadjusted HR

Adjusted HR

P-valueii

  

(95% CI)

(95% CI) i

 

(95% CI)

(95% CI) i

 

(95% CI)

(95% CI) i

 

Observational cohort

          

Cohort 1: ART (CD4 < 200)

52/118

---

---

---

---

---

---

---

---

---

Cohort 2: ZDV plus sdNVP (CD4 > 500)

15/128

---

---

---

---

---

---

---

---

---

Intervention armiii

          

RCT arm A: Triple ARV (CD4 200–500)iv/v

97/412

---

---

---

---

---

---

1

1

---

RCT arm B: ZDV plus sdNVP (CD4 200–500)iv/v

84/412

---

---

---

---

---

---

1.09 (0.77,1.52)

0.78 (0.54,1.11)

0.166

Country

          

Burkina Faso

70/345

1

1

---

1

---

---

1

1

---

Kenya

157/441

1.66 (0.88,3.13)

1.56 (0.80,3.07)

0.192

1.11 (0.41,3.02)

---

---

2.70 (1.76,4.13)

2.76 (1.79,4.25)

<0.001

South Africa

21/281

---

---

---

---

---

---

0.42 (0.23,0.75)

0.52 (0.26,1.01)

0.054

Age (enrolment)

248/1070

0.95 (0.88,1.02)

0.96 (0.89,1.04)

0.312

0.95 (0.82,1.11)

---

---

1.00 (0.97,1.04)

---

---

BMI (enrolment)

248/1070

1.02 (0.93,1.11)

---

---

0.97 (0.87,1.09)

---

---

0.96 (0.92,1.01)

1.00 (0.95,1.05)

0.964

Secondary or higher education versus none or primary level (enrolment)

90/511

 

---

---

 

---

---

0.57 (0.40,0.81)

0.85 (0.56,1.26)

0.413

HIV stage 3 vi versus stage 1 or 2 (enrolment)

48/101

1.31 (0.71,2.44)

---

---

Insufficient observations

---

---

2.11 (1.18,3.79)

2.11 (1.19,3.75)

0.011

Most poor SES category versus poor or least poor (enrolment)

73/209

1.44 (0.73,2.85)

---

---

5.13 (1.83,14.41)

4.08 (1.54,10.75)

0.005

1.57 (1.06,2.32)

1.13 (0.75,1.70)

0.567

First pregnancy (enrolment)

37/185

0.90 (0.34,2.41)

---

---

1.35 (0.44,4.19)

---

---

0.88 (0.56,1.40)

---

---

Never breastfed

69/285

1.49 (0.80,2.78)

---

---

0.24 (0.03,1.86)

---

---

1.00 (0.66,1.50)

---

---

Prolonged breastfeeding

          

< 6 months

138/640

1

1

---

1

1

---

1

1

---

> = 6 months

31/103

0.79 (0.28,2.23)

---

---

0.77 (0.19,3.13)

1.12 (0.27,4.76)

0.873

1.46 (0.88,2.41)

1.62 (1.00,2.62)

0.051

0 duration (did not breast-feed)

69/285

1.43 (0.74,2.79)

---

---

0.23 (0.03,1.80)

0.33 (0.04,2.48)

0.280

1.06 (0.69,1.61)

1.05 (0.68,1.62)

0.831

Cumulative duration on ARV (in years, continuous scale)

248/1070

0.03 (0.00,0.27)

0.04 (0.00,0.29)

0.002

0.02 (0.00,vii)

---

---

0.03 (0.00,0.24)

0.05 (0.01,0.37)

0.003

  1. CI = confidence interval; BMI = body mass index; SES = socio-economic status.
  2. i: Test of proportional hazards assumption not violated for cohort specific and RCT models.
  3. ii: log rank test.
  4. iii: ART = antiretroviral therapy; triple ARV = triple-combination antiretroviral prophylaxis; ZDV plus sdNVP = zidovudine plus single-dose nevirapine.
  5. iv: difference test result comparing the two RCT trial arms i.e. null that difference = 0 (P-value = 0.636).
  6. v: equivalence test results comparing the two RCT trial arms (P-value = 0.323; null hypothesis of dissimilarity rejected at pre-specified level of 5%, and equivalence assumed).
  7. vi: no participant s in the RCT arms with stage 4 at enrolment.
  8. vii: small sample size (P-value = 0.567).
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BMC Infectious Diseases

ISSN: 1471-2334

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