Subgroup analyses according to country and route
| Diagnostic tool | Variables | Subgroup | Sensitivity | Specificity | PLR | NLR | DOR | AUC |
| US | Country | Asia | 0.89 (0.85 to 0.93) | 0.84 (0.71 to 0.92) | 5.76 (3.00 to 11.07) | 0.12 (0.09 to 0.18) | 46.71 (20.69 to 105.41) | 0.92 (0.89 to 0.94) |
| Europe or America | 0.92 (0.86 to 0.95) | 0.88 (0.82 to 0.92) | 7.37 (5.16 to 10.53) | 0.09 (0.06 to 0.16) | 63.54 (36.63 to 110.23) | 0.95 (0.93 to 0.97) | ||
| Difference between subgroups | 0.333 | 0.520 | 0.516 | 0.348 | 0.540 | 0.068 | ||
| Route | Transvaginal | 0.94 (0.88 to 0.97) | 0.89 (0.83 to 0.93) | 8.40 (5.52 to 12.77) | 0.07 (0.04 to 0.13) | 86.75 (56.93 to 132.20) | 0.97 (0.95 to 0.98) | |
| Transabdominal | 0.91 (0.86 to 0.94) | 0.80 (0.60 to 0.91) | 4.46 (2.03 to 9.78) | 0.12 (0.07 to 0.20) | 34.48 (11.10 to 107.05) | 0.93 (0.90 to 0.95) | ||
| Both | 0.82 (0.74 to 0.88) | 0.84 (0.74 to 0.91) | 5.10 (2.90 to 8.99) | 0.22 (0.14 to 0.34) | 22.55 (7.70 to 66.05) | 0.88 (0.85 to 0.90) | ||
| Difference between subgroups | 0.027 | 0.438 | 0.221 | 0.008 | 0.035 | <0.001 | ||
| Doppler US | Country | Asia | 0.89 (0.82 to 0.93) | 0.82 (0.74 to 0.89) | 5.06 (3.37 to 7.59) | 0.13 (0.08 to 0.22) | 33.72 (17.44 to 65.22) | 0.93 (0.90 to 0.95) |
| Europe or America | 0.94 (0.92 to 0.96) | 0.85 (0.79 to 0.90) | 6.41 (4.50 to 9.13) | 0.07 (0.04 to 0.10) | 76.07 (44.70 to 129.46) | 0.97 (0.95 to 0.98) | ||
| Difference between subgroups | 0.107 | 0.533 | 0.389 | 0.075 | 0.060 | 0.008 | ||
| Route | Transvaginal | 0.94 (0.91 to 0.95) | 0.87 (0.82 to 0.90) | 6.98 (5.02 to 9.70) | 0.07 (0.05 to 0.10) | 74.55 (45.34 to 122.60) | 0.96 (0.94 to 0.98) | |
| Transabdominal | 0.94 (0.77 to 0.99) | 0.86 (0.72 to 0.94) | 6.87 (3.19 to 14.82) | 0.07 (0.02 to 0.31) | 66.82 (15.41 to 289.83) | 0.95 (0.93 to 0.97) | ||
| Both | 0.92 (0.80 to 0.97) | 0.65 (0.54 to 0.75) | 2.66 (2.02 to 3.51) | 0.12 (0.05 to 0.30) | 15.56 (8.20 to 29.52) | 0.85 (0.82 to 0.88) | ||
| Difference between subgroups | 0.913 | 0.004 | <0.001 | 0.544 | 0.001 | <0.001 | ||
| CEUS | Country | Asia | 0.97 (0.90 to 0.99) | 0.91 (0.83 to 0.96) | 11.15 (5.76 to 21.61) | 0.03 (0.01 to 0.12) | 201.55 (90.19 to 450.41) | 0.99 (0.97 to 0.99) |
| Europe or America | 0.97 (0.90 to 0.99) | 0.91 (0.81 to 0.96) | 11.32 (4.77 to 26.87) | 0.03 (0.01 to 0.12) | 133.64 (41.55 to 429.78) | 0.99 (0.97 to 0.99) | ||
| Difference between subgroups | 1.000 | 1.000 | 0.978 | 1.000 | 0.570 | 1.000 | ||
| Route | Transvaginal | 0.98 (0.92 to 1.00) | 0.90 (0.81 to 0.95) | 9.74 (4.93 to 19.24) | 0.02 (0.00 to 0.10) | 123.98 (50.61 to 303.71) | 0.99 (0.98 to 1.00) | |
| Transabdominal | 0.94 (0.89 to 0.97) | 0.95 (0.91 to 0.97) | 18.69 (9.88 to 35.36) | 0.06 (0.04 to 0.11) | 245.86 (95.66 to 631.92) | 0.98 (0.97 to 0.99) | ||
| Difference between subgroups | 0.173 | 0.217 | 0.171 | 0.361 | 0.303 | 0.166 |
AUC, area under the curve; CEUS, contrast-enhanced US ; DOR, diagnostic OR; NLR, negative likelihood ratio; PLR, positive likelihood ratio; US, ultrasonography.