Table 3. Sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, false negative and false positive results, for I-index cut-offs ≥ 34.2 µmol/L in different subgroups of patients.
| Primary care | Outpatients | Inpatients | Emergency room | All samples | |
|---|---|---|---|---|---|
| Sensitivity, % (95% CI) |
28.4 (25.3 to 31.8) |
25.1 (21.2 to 29.4) |
42.0 (38.2 to 46.0) |
23.8 (19.7 to 28.4) |
30.8 (28.9 to 32.8) |
| Specificity, % (95% CI) |
99.6 (99.5 to 99.7) |
99.7 (99.5 to 99.8) |
99.9 (99.6 to 100.0) |
99.9 (99.7 to 100.0) |
99.7 (99.6 to 99.8) |
| PPV, % (95% CI) | 83.9 (78.8 to 87.9) |
88.4 (81.5 to 93.0) |
98.8 (96.6 to 99.6) |
97.7 (92.1 to 99.4) |
91.7 (89.5 to 93.5) |
| NPV, % (95% CI) | 95.1 (94.7 to 95.5) |
94.1 (93.5 to 94.7) |
87.5 (86.3 to 88.7) |
90.0 (88.8 to 91.0) |
93.3 (92.9 to 93.6) |
| LR+ (95% CI) | 73.14 (52.58 to 101.73) |
92.00 (53.17 to 159.18) |
343.64 (110.48 to 1068.88) |
293.75 (72.61 to 1188.35) |
106.32 (81.76 to 138.25) |
| LR- (95% CI) | 0.72 (0.69 to 0.759) |
0.75 (0.71 to 0.79) |
0.58 (0.54 to 0.62) |
0.76 (0.72 to 0.81) |
0.69 (0.68 to 0.71) |
| False negatives, N (%)* | 524 (4.75) |
320 (5.75) |
349 (11.42) |
276 (9.74) |
1469 (6.53) |
| False positives, N (%)* |
40 (0.36) |
14 (0.25) |
3 (0.10) |
2 (0.07) |
59 (0.26) |
| Samples, N (%)† | 11,028 (49.05) |
5567 (24.76) |
3055 (13.59) |
2835 (12.61) |
22,485 (100.00) |
| *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. | |||||