Table 3.
The diagnostic accuracy of routine clinical findings or their combinations for detection of esophageal varices in rural Africa where schistosomiasis is endemic: diagnostic tests, study size, and measures of diagnostic accuracy
| Diagnostic tests | N | Sensitivity (95%CI) |
Specificity (95%CI) |
PPV (95%CI) |
NPV (95%CI) |
Accuracy (95%CI) |
NNM (95%CI) |
| Model 1 (involves ultrasonography) | 107 | 97% (90–99%) |
71% (48–89%) |
93% (88–97%) |
83% (61–94%) |
92% (85–96%) |
13 (7–25) |
| Model 2 (no ultrasonography) | 102 | 96% (90–99%) |
76% (53–92%) |
94% (89–97%) |
84% (63–94%) |
92% (85–97%) |
13 (7–25) |
| Platelet count spleen diameter ratio <909 | 107 | 92% (84–97%) |
71% (48–89%) |
93% (87–96%) |
68% (50–82%) |
88% (80–93%) |
8 (5–14) |
| ≥4 Number lifetime of episodes of upper gastrointestinal bleeding (UGIB) | 107 | 100% (96–100%) |
0 (0–16%) |
83% - | - | 80% (72–87%) |
5 (4–8) |
| Fibrosis patterns EF or X* | 107 | 99% (94–100%) |
38% (18–62%) |
87% (82–90%) |
89% (51–98%) |
87% (79–93%) |
8 (5–14) |
| Palpable spleen | 102 | 96% (90–99%) |
33% (15–57%) |
85% (80–88%) |
70% 40-89% | 83% (79–90%) |
6 (5–10) |
| Platelet count ≤140 x109/L | 107 | 95% (89–99%) |
57% (34–79%) |
90% (85–94%) |
75% (56–89%) |
88% (80–93%) |
8 (5–14) |
| Heart rate ≥68beats/min | 107 | 100% (96–100%) |
0 (0–16%) |
80% - | - | 80% (72–87%) |
5 (4–8) |
| Age ≤39 years | 107 | 100% (96–100%) |
0 (0–16%) |
80% - | - | 80% (72–87%) |
5 (4–8) |
Model 1 includes following factor variables platelet count spleen diameter ratio <909, WHO periportal fibrosis patterns EF or X, number lifetime of episodes of UGIB≥4, heart rate ≥68beats/minute.
Model 2 includes age ≤39 years, heart rate ≥68 beats/minute, palpable spleen, ≥4 Number lifetime of episodes of UGIB, platelet count≤140 x 109 /L.
PPV-positive predictive value, NPV-negative predictive value, NNM . number needed to misdiagnose.