Table 3.
Specificity of all algorithms
| Single-tier | STTT | MTTT-strict | MTTT-permissive | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| No. of true negative (specificity %) | 95%-CI | No. of true negative (specificity %) | 95%-CI | No. of true negative (specificity %) | 95%-CI | No. of true negative (specificity %) | 95%-CI | |||
| PopC sera (n = 231) | ||||||||||
| Enz1 | 206 (89.2)1 | 84.4–92.9 | Enz1/RecomL | 224 (97.0) | 93.9–98.8 | Enz1/C6 | 223 (96.5)2 | 93.3–98.5 | 221 (95.7)4,5 | 92.2–97.9 |
| Enz2 | 206 (89.2)1 | 84.4–92.9 | Enz2/RecomL | 224 (97.0) | 93.9–98.8 | Enz2/C6 | 223 (96.5)2 | 93.3–98.5 | 222 (96.1)3,4,5 | 92.7–98.2 |
| Lia | 210 (90.9)1 | 86.4–94.3 | Lia/RecomL | 225 (97.4) | 94.4–99.0 | Lia/C6 | 223 (96.5)2 | 93.3–98.5 | 220 (95.2)*,5 | 91.6–97.6 |
| C6 | 216 (93.5)1 | 89.5–96.3 | C6/RecomL | 225 (97.4) | 94.4–99.0 | |||||
| CRC sera (n = 50) | ||||||||||
| Enz1 | 33 (66.0)1 | 51.2–78.8 | Enz1/RecomL | 45 (90.0) | 78.2–96.7 | Enz1/C6 | 43 (86.0)2 | 73.3–94.2 | 41 (82.0)4,5 | 68.6–91.4 |
| Enz2 | 33 (66.0)1 | 51.2–78.8 | Enz2/RecomL | 45 (90.0) | 78.2–96.7 | Enz2/C6 | 43 (86.0)2 | 73.3–94.2 | 41 (82.0)4,5 | 68.6–91.4 |
| Lia | 31 (62.0)1 | 47.2–75.4 | Lia/RecomL | 44 (88.0) | 75.7–95.5 | Lia/C6 | 43 (86.0)2 | 73.3–94.2 | 42 (84.0)4,5 | 70.9–92.8 |
| C6 | 39 (78.0)1 | 64.0–88.5 | C6/RecomL | 46 (92.0) | 80.0–97.8 | |||||
1p < 0.01 as compared with equivalent STTT (McNemar/exact McNemar)
2p < 0.05 as compared with single-tier C6-ELISA (one-sample t test)
3p < 0.05 as compared with single-tier C6 (exact McNemar)
4p < 0.01 as compared with equivalent single-tier (exact McNemar) | (*Lia vs. Lia/C6 (permissive) p = 0.021)
5Not significant as compared with equivalent MTTT-strict (one-sample t test)
A test result was considered to be (true) negative when both the IgM and the IgG component were negative. A test result was considered to be (false) positive when either or both components were positive
95%-CI, 95% confidence interval; STTT, standard two-tier testing; MTTT, modified two-tier testing; Enz1, Enzygnost-1; Enz2, Enzygnost-2; Lia, Liaison; C6, C6-ELISA; RecomL, RecomLine; EM, erythema migrans; PopC, population control; CRC, cross-reactive control; strict, counting equivocal EIA results as negative; permissive, counting equivocal EIA results as positive