A comparative study on indicators of vitamin A status and risk factors for sensitivity and specificity of the methods to detect vitamin A deficiency

Table 4 Factors influencing retinol binding proteins accuracy in the assessment of VAD in children 36–59 months of age in rural Burkina Faso

Parameters	Season		CRP		AGP		Helminth infections
Parameters	Dry n = 47	Rainy n = 43	< 5.0 mg/L n = 86	≥ 5.0 mg/L n = 4	< 1.0 g/L n = 65	≥ 1.0 g/L n = 25	Negative n = 45	Positive n = 36
Unadjusted retinol-binding protein
Prevalence of VAD¹	42.6 (29.9; 56.3)	23.5 (13.7; 37.4)	32.7 (24.2; 42.5)	50.0 (4.0; 96.0)	37.3 (27.0; 48.9)	23.3 (11.2; 42.4)	33.3 (21.6; 47.6)	29.5 (17.7; 44.9)
Sensitivity²	-	-	-	-	-	-
Specificity³	61.7	76.7	69.8	50.0	64.6	80.0	68.9	72.2
Diagnosis accuracy⁶	61.7 (46.8; 74.7)	76.7 (61.4; 87.2)	69.8 (59.1; 78.6)	50.0 (4.0; 96.0)	64.6 (52.1; 75.4)	80.0 (58.8; 91.8)	68.9 (53.6; 80.9)	72.2 (55.0; 84.7)
Adjusted retinol-binding protein
Prevalence of VAD¹	44.4 (31.6; 58.1)	29.4 (18.3; 43.6)	38.6 (29.5; 48.5)	0	38.7 (28.2; 50.3)	33.3 (18.5; 52.5)	37.2 (24.9; 51.5)	36.4 (23.3; 51.8)
Sensitivity²	-	-	-	-	-	-
Specificity³	61.7	74.4	66.3	-	63.1	80.0	66.7	69.4
Diagnosis accuracy⁴	61.7 (46.8; 74.7)	74.4 (59.0; 85.5)	66.3 (55.5; 75.6)	100	63.1 (50.5; 74.1)	80.0 (58.8; 91.8)	66.7 (51.4; 79.1)	69.4 (52.2; 82.6)

CRP, C-reactive protein; AGP, alpha 1-acid glycoprotein; VAD, Vitamin A deficiency; RBP, Retinol binding-protein; TLR, Total liver vitamin A reserves
Values are presented as % (95% Confidence Interval)
¹Dry season, n = 54; Rainy season, n = 51; CRP < 5.0 mg/L, n = 101; CRP ≥ 5.0 mg/L, n = 4; AGP < 1.0 g/L, n = 75; AGP ≥ 1.0 g/L, n = 30; No helminth, n = 51; Presence of helminths, n = 44
²Sensitivity [True Positive / (True Positive + False Negative)]
³Specificity [True Negative / (False Positive + True Negative)]
⁴Diagnosis accuracy [True Positive + True Negative]

ISSN: 1743-7075