Development of an algorithm for determination of the likelihood of virological failure in HIV-positive adults receiving antiretroviral therapy in decentralized care

Figures & data

Table 1. Baseline characteristics of study participants.

Characteristic	Started ART (n = 729)	12-month data available (n = 494)	12-month data unavailable (n = 116)	P
Age, years	32 (28–40)	33 (28–40)	30 (28–38)	0.13
Female	431 (59)	313 (63)	56 (48)	<0.01
BMI, kg/m^2	19 (18–21)	20 (18–22)	19 (18–21)	0.51
MUAC, cm	23 (21–25)	23 (21–25)	23 (21–25)	0.59
Karnofsky status, %	80 (80–90)	90 (80–90)	90 (80–90)	0.37
WHO clinical stage				0.68
Stage I	131 (18)	100 (20)	18 (16)
Stage II	207 (28)	144 (29)	34 (29)
Stage III	313 (43)	201 (41)	52 (45)
Stage IV	77 (11)	48 (10)	12 (10)
CD4 count, cells/mm^3	187 (116–274)	192 (127–274)	199 (115–302)	0.64
Lymphocyte count, cells/mm^3	1400 (1100–1800)	1400 (1100–1900)	1400 (1000–1800)	0.93
Haemoglobin, g/dL	11.5 (10.2–12.7)	11.6 (10.3–12.7)	11.6 (10.3–13.0)	0.93
Active tuberculosis at baseline	137 (19)	88 (18)	23 (21)	0.61

Data presented as n (%) of patients or median value (interquartile range).

P calculated with Chi-square and Mann-Whitney U test for categorical and continuous variables, respectively.

Abbreviations: ART, antiretroviral therapy; BMI, body-mass index; MUAC, mid-upper arm circumference.

Figure 1. Flow chart of study participants.

Table 2. Variables associated with virological failure in multivariate analysis.

Variables	Unadjusted OR(95% CI)	Adjusted OR^a(95% CI)
MUAC <23 cm ♀/<24 cm ♂	2.6 (1.5–4.7)	2.7 (1.4–4.9)
CD4 count <350 cells/mm^3	5.2 (2.6–10.6)	5.5 (2.6–11.6)
Previous ART interruption	5.2 (1.6–16.6)	4.2 (1.2–14.1)

Abbreviations: OR, odds ratio; MUAC, mid-upper arm circumference.

^a Adjusted for age and the other variables remaining in the model.

Table 3. Performance of the Viral Load Testing Criteria (VLTC) and WHO criteria.

	n/N (%)	Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)	NNT
VLTC:
Any criteria	299/494 (61)	91 (81–97)	43 (39–48)	17 (16–19)	97 (94–99)	5.8
Two or more criteria	75/494 (15)	37 (24–51)	88 (84–91)	28 (20–37)	91 (90–93)	3.6
Three criteria	3/494 (1)	4 (0–12)	100 (99–100)	67 (16–96)	89 (88–91)	1.5
WHO criteria:
Clinical	99/467 (21)	40 (28–54)	82 (77–85)	23 (17–31)	91 (89–92)	4.3
Immunological	79/490 (16)	45 (31–59)	88 (84–91)	32 (24–40)	92 (91–94)	3.2
Clinical and/or immunological	153/494 (31)	67 (53–79)	74 (69–78)	25 (21–30)	94 (92–96)	4.0

Abbreviations: CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value; NNT, numbers needed to test.

Figure 2. Algorithms for viral load testing.