Table 5. Sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, false negative and false positive results, adjusted by I-index cut-off in different subgroups of patients in haemolysed samples (H > 0.6 g/L).
| Primary care | Outpatients | Inpatients | Emergency room | All samples | |
|---|---|---|---|---|---|
| I-index ≤ 17.1 µmol/L | I-index ≤ 15.4 µmol/L | ||||
| Sensitivity, % (95% CI) |
81.3 (71.1 to 88.5) |
72.4 (59.8 to 82.3) |
82.9 (75.3 to 88.6) |
78.0 (71.8 to 83.2) |
79.2 (75.2 to 82.6) |
| Specificity, % (95% CI) |
87.3 (85.5 to 88.9) |
89.6 (87.5 to 91.4) |
93.6 (91.1 to 95.4) |
94.1 (92.6 to 95.3) |
90.5 (89.6 to 91.4) |
| PPV, % (95% CI) | 24.0 (19.2 to 29.6) |
30.0 (23.0 to 38.0) |
75.0 (67.1 to 81.5) |
69.0 (62.2 to 74.7) |
47.8 (44.2 to 51.3) |
| NPV, % (95% CI) | 99.0 (98.3 to 99.4) |
98.1 (97.0 to 98.9) |
95.9 (93.9 to 97.3) |
96.2 (95.0 to 97.2) |
97.6 (97.0 to 98.0) |
| LR+ (95% CI) | 6.39 (5.39 to 7.58) |
6.96 (5.44 to 8.90) |
12.88 (9.21 to 18.00) |
13.24 (10.43 to 16.81) |
8.37 (7.53 to 9.29) |
| LR- (95% CI) | 0.21 (0.13 to 0.34) |
0.31 (0.20 to 0.47) |
0.18 (0.12 to 0.27) |
0.23 (0.18 to 0.30) |
0.23 (0.19 to 0.28) |
| False negatives, N (%)* |
14 (0.88) |
16 (1.60) |
21 (3.23) |
44 (3.17) |
95 (2.05) |
| False positives, N (%)* |
193 (12.13) |
98 (9.80) |
34 (5.22) |
70 (5.04) |
395 (8.53) |
| Samples, N (%)† | 1591 (34.36) |
1000 (21.60) |
651 (14.06) |
1388 (29.98) |
4630 (100) |
| *Percentage relative to its subgroup. †Percentage relative to all samples studied in this cohort with Tbil requested. PPV - positive predictive values. NPV - negative predictive value. LR+ - positive likelihood ratio. LR- - negative likelihood ratio. CI – confidence interval. I-index – icteric index. Tbil – total bilirubin. H – haemolysis index. | |||||