Table 5 Bi-variable and multi-variable Weibull regression analysis for predictors of virological failure among adult HIV patients on first-line ART in Amhara regional referral hospitals; Ethiopia from September 2015 to December 2018(N = 490)

Event

Censored

Age in year

15–24

13

65

2.02 (0.77–5.33)

0.67 (0.19–2.35)

25–34

27

169

1.68 (0.69–4.07)

1.24 (0.47–3.23)

35–44

15

127

1.36 (0.52–.3.50)

0.80 (0.29–2.21)

> = 45

6

68

1

1

Sex

Male

30

173

1.48 (0.90–2.46)

1.46 (0.83–2.57)

Female

31

256

1

1

Educational status

No education

15

113

1

1

Primary

22

100

1.62 (0.84–3.12)

1.32 (0.64–2.71)

Secondary above

24

216

0.81 (0.42–1.56)

0.71 (0.33–1.49)

Occupation

Un employed

19

85

2.21 (1.23–3.97)

1.52 (0.73–3.15)

Employed

9

81

1.06 (0.50–2.25)

1.88 (0.80–4.42)

Daily laborer

5

19

2.54 (0.99–6.58)

1.35 (0.49–3.75)

Self-employed

28

244

1

1

CPT

Yes

32

239

1

1

No

29

190

1.40 (0.84–2.32)

1.8 (1.03–3.16)*

Baseline functional status

Working

40

345

1

1

Ambulator/bedridden

21

84

1.98 (1.16–3.36)

1.23 (0.65–2.32)

Adherence

Good

32

382

1

1

Fair/poor

29

47

6.16 (3.7–10)

5.46 (3.06–9.74)*

TB/HIV-co-infection

Yes

15

77

1.91 (1.07–3.43)

1.27 (0.65–2.51)

No

46

352

1

1

First-line drug regimen

EFV based

42

395

1

1

NVP based

19

34

3.82 (2.22–6.5)

3.53 (1.73–7.21)*

Hemoglobin level

Anemic

25

81

2.6 (1.57–4.35)

1.46 (0.83–2.57)

Not anemic

36

348

1

1

Baseline CD4 count

<=200

29

163

2.83 (0.86–9.3)

3.9 (1.07–13.9)*

201–350

18

110

2.47 (0.72–8.41)

4.1 (1.12–15)*

351–500

11

90

1.96 (0.54–7.04)

2.14 (0.54–8.5)

> 500

3

66

1

1

Baseline WHO stage

Stage I/II

29

275

1

1

Stage III/IV

32

154

1.80 (1.1–2.98)

1.15 (0.61–2.20)

Past OI

Yes

23

127

1.42 (0.85–2.39)

1.21 (0.61–2.41)

No

38

302

1

1