Table 3.
Performance characteristics estimate of normal versus different groups
| Parameters | Cutoff point | Sensitivity | Specificity | PPV | NPV | LR(+) | LR(−) |
|---|---|---|---|---|---|---|---|
|
normal versus all abnormal appendix (n= 456) | |||||||
|
WBCs count 95% CIs |
9.400 X103 |
76.81 (72.5 - 80.7) |
65.52 (45.7 - 82.1) |
97.0 (4.6 - 98.6) |
16.1 (10.0 - 24.0) |
2.23 (1.7- 2.9) |
0.35 (0.2 - 0.6) |
|
Neutrophil count 95% Cls |
7.540X103 |
70.96 (66.4 - 75.2) |
65.52 (45.7 - 82.1) |
96.8 (94.2 - 98.5) |
13.3 (8.2 - 20.0) |
2.06 (1.6 - 2.7) |
0.44 (0.3 - 0.7) |
|
normal versus inflamed appendix (n= 379) | |||||||
|
WBCs count 95% CIs |
9.400 X103 |
75.43 (70.6 - 79.8) |
65.52 (45.7 - 82.1) |
96.4 (93.4 - 98.2) |
18.1 (11.2 - 26.9) |
2.19 (1.7 - 2.9) |
0.38 (0.2 - 0.6) |
|
Neutrophil count 95% Cls |
8.080X103 |
65.43 (60.2 - 70.4) |
68.97 (49.2 - 84.7) |
96.2 (92.9 - 98.3) |
14.2 (8.9 - 21.1) |
2.11 (1.6 - 2.7) |
0.50 (0.3 - 0.9) |
|
normal versus complicated appendix (n= 106) | |||||||
|
WBCs count 95% CIs |
11.100 X103 |
76.62 (65.6 - 85.5) |
72.41 (52.8 - 87.3) |
88.10 (77.8 - 94.7) |
53.80 (37.2 - 69.9) |
2.78 (2.1 - 3.6) |
0.32 (0.2 - 0.7) |
| Neutrophil count 95% Cls | 7.540X103 | 81.82 (71.4 - 89.7) | 65.52 (45.7 - 82.1) | 86.30 (76.2 - 93.2) | 57.60 (38.9 - 74.8) | 2.37 (1.8 - 3.2) | 0.28 (0.1 - 0.6) |
WBCs white blood cells, 95% CIs 95% confidence intervals, NPV negative predictive value, PPV positive predictive value, LR likelihood ratio.