Article Figures & Data
Figures
- Fig 1
Correlation between Elecsys and Architect HBsAg quantification systems. Individual levels of HBsAg are plotted (gray dots), with Architect as the independent and Elecsys as the dependent variable. Univariate linear regression (black line) has also been fitted.
- Fig 2
Overall Bland-Altman plot. HBsAg techniques are compared by plotting the differences of Elecsys to Architect (y axis) with their means (x axis). The average between-method difference (0.2 log10 IU/ml) is represented by the middle solid line, while the limit of agreement (−0.5, 0.9 log10 IU/ml) is represented by the two outer solid lines. Five values lie outside this range.
Tables
- Table 2
Comparison of mean differences between HBsAg quantification methods by various clinical parametersa
Clinical parameter No. of samplese Mean differenceb Limit of agreement (±2 SD) HBeAg status HBeAg positive 69 0.182 −0.560, 0.923 HBeAg negative 57 0.143 −0.500, 0.786 HBV DNA viral load >2,000 IU/ml 75 0.180 −0.655, 1.014 ≤2,000 IU/ml 51 0.141 −0.284, 0.566 HBV genotypec A 59 0.196 −0.564, 0.956 D 7 0.036 −0.165, 0.237 E 7 0.030 −0.251, 0.311 G+A/G 15 0.201 −0.275, 0.676 Precore (W28) mutation Yes 23 0.111 −0.279, 0.500 No 63 0.195 −0.543, 0.933 YMDD mutation Yes 60 0.156 −0.543, 0.855 No 20 0.234 −0.403, 0.871 s120/s145 mutationsd Yes 6 −0.078 −0.403, 0.247 No 81 0.186 −0.487, 0.859 HCV-positive serology Yes 15 0.160 −0.924, 1.243 No 110 0.164 −0.473, 0.802 HDV-positive serology Yes 9 0.251 −0.485, 0.988 No 116 0.157 −0.541, 0.856 CD4+ T cell count >500 cells/mm3 42 0.195 −0.341, 0.732 350–500 cells/mm3 36 0.155 −0.791, 1.102 <350 cells/mm3 48 0.143 −0.464, 0.751 ↵a Bland-Altman analysis stratified on various HBV and HIV cofactors.
↵b Difference of Elecsys to Architect.
↵c P values of <0.1 when mean between-assay differences are compared betwen D versus G+A/G and E versus G+A/G.
↵d P values of <0.1 when mean between-assay differences are compared between strata.
↵e Total number of samples with available data for each stratum.
- Table 3
Comparison of mean differences between various clinical parameters stratified on below/above-median HBsAg levelsa
Clinical parameter HBsAg levels below median HBsAg levels above median No. of samplesd Mean differenceb Limit of agreement (±2 SD) No. of samplesd Mean differenceb Limit of agreement (±2 SD) Overall 62 0.100 −0.500, 0.800 64 0.200 −0.500, 0.900 HBeAg status HBeAg positive 13 0.116 −0.384, 0.615 56 0.197 −0.591, 0.985 HBeAg negative 49 0.132 −0.553, 0.817 8 0.208 −0.044, 0.460 HBV-DNAc >2,000 IU/ml 54 0.125 −0.550, 0.800 21 0.321 −0.799, 1.440 ≤2,000 IU/ml 8 0.153 −0.292, 0.597 43 0.139 −0.288, 0.565 HBV genotype A 15 0.118 −0.205, 0.442 44 0.222 −0.634, 1.079 D 3 0.003 −0.268, 0.273 4 0.061 −0.095, 0.216 E 4 0.077 −0.215, 0.369 3 -0.033 −0.293, 0.228 G+A/G 9 0.168 −0.310, 0.647 6 0.249 −0.248, 0.746 Precore (W28) mutation Yes 12 0.087 −0.241, 0.415 11 0.136 −0.322, 0.595 No 16 0.117 −0.209, 0.443 47 0.222 −0.608, 1.051 YMDD mutation Yes 20 0.081 −0.188, 0.349 40 0.194 −0.634, 1.022 No 5 0.152 −0.266, 0.570 15 0.262 −0.437, 0.960 s120/s145 mutationsc Yes 2 0.043 0.034, 0.052 4 −0.139 −0.482, 0.205 No 29 0.108 −0.238, 0.454 52 0.230 −0.559, 1.019 HCV-positive serology Yes 13 0.158 −1.010, 1.326 2 0.170 −0.092, 0.431 No 49 0.121 −0.315, 0.557 61 0.200 −0.559, 0.958 HDV-positive serology Yes 6 0.268 −0.660, 1.196 3 0.219 0.139, 0.298 No 56 0.114 −0.500, 0.727 60 0.198 −0.568, 0.963 CD4+ T cell count >500 cells/mm3 16 0.116 −0.607, 0.839 26 0.244 −0.119, 0.607 350-500 cells/mm3 16 0.141 −0.610, 0.892 20 0.167 −0.930, 1.264 <350 cells/mm3 30 0.129 −0.435, 0.693 18 0.167 −0.521, 0.856 ↵a Bland-Altman analysis stratified on various HBV and HIV cofactors, presented among patients with high or low values of HBsAg quantity. HBsAg levels are given by the Elecsys technique (median = 3.98 log10 Iu/ml).
↵b Difference of Elecsys to Architect.
↵c P values of <0.1 when mean between-assay differences are compared between strata at HBsAg levels above the median.
↵d Total number of samples with available data for each stratum.
