Table 2. 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.
| Primary care | Outpatients | Inpatients | Emergency room | All samples | |
|---|---|---|---|---|---|
| I-index ≤ 17.1 µmol/L | I-index ≤ 15.4 µmol/L | ||||
| Sensitivity, % (95% CI) |
99.6 (98.8 to 99.9) |
97.4 (95.5 to 98.6) |
92.7 (90.3 to 94.5) |
98.6 (96.8 to 99.4) |
97.0 (96.2 to 97.7) |
| Specificity, % (95% CI) |
67.3 (66.4 to 68.2) |
74.5 (73.3 to 75.7) |
86.8 (85.4 to 88.1) |
79.1 (77.4 to 80.6) |
72.9 (72.3 to 73.5) |
| PPV, % (95% CI) | 17.8 (16.6 to 19.0) |
24.1 (22.1 to 26.2) |
63.3 (60.1 to 66.5) |
40.8 (37.6 to 44.1) |
27.2 (26.2 to 28.2) |
| NPV, % (95% CI) | 100.0 (99.9 to 100.0) |
99.7 (99.5 to 99.8) |
98.0 (97.3 to 98.5) |
99.7 (99.4 to 99.9) |
99.6 (99.5 to 99.7) |
| LR+ (95% CI) | 3.04 (2.96 to 3.13) |
3.82 (3.63 to 4.01) |
7.04 (6.34 to 7.81) |
4.71 (4.36 to 5.09) |
3.58 (3.49 to 3.66) |
| LR- (95% CI) | 0.01 (0.00 to 0.02) |
0.04 (0.02 to 0.06) |
0.08 (0.06 to 0.11) |
0.02 (0.01 to 0.04) |
0.04 (0.03 to 0.05) |
| False negatives, N (%)* |
3 (0.03) |
11 (0.20) |
44 (1.44) |
5 (0.18) |
63 (0.28) |
| False positives, N (%)* |
3370 (30.56) |
1312 (23.57) |
323 (10.57) |
518 (18.27) |
5523 (24.57) |
| Samples, N (%)† | 11,028 (49.06) |
5567 (24.77) |
3049 (13.56) |
2835 (12.61) |
22,479 (100.00) |
| Test saved, N (%)† | 6926 (30.81) |
3828 (17.03) |
2130 (9.48) |
1955 (8.70) |
14,839 (66.01) |
| *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. | |||||