TABLE 5.
Agreement between diagnostic assays for leptospirosis in classifying cases as positive and controls as negative
| Assays compared | No. (%) of cases testing positivea | No. (%) of controls testing negativeb | Kappa correlation (95% CI)c |
|---|---|---|---|
| ELISA-MAT | 115 (86.5) | 604 (94.1) | 0.78 (0.73-0.84) |
| ELISA-IHA | 95 (71.4) | 597 (93.0) | 0.66 (0.59-0.73) |
| ELISA-LDS | 110 (82.7) | 559 (87.1) | 0.62 (0.55-0.69) |
| ELISA-DST | 112 (84.2) | 620 (96.6) | 0.86 (0.81-0.91) |
| IHA-MAT | 105 (79.0) | 595 (92.7) | 0.70 (0.63-0.76) |
| IHA-LDS | 101 (75.9) | 553 (86.1) | 0.57 (0.50-0.64) |
| IHA-DST | 101 (75.9) | 608 (94.7) | 0.73 (0.67-0.80) |
| MAT-LDS | 124 (93.2) | 555 (86.5) | 0.66 (0.60-0.72) |
| MAT-DST | 122 (91.7) | 614 (95.6) | 0.85 (0.80-0.90) |
| DST/LDS | 117 (88.0) | 569 (88.6) | 0.67 (0.61-0.74) |
a
For each assay, a case was considered positive if the acute- and/or convalescent-phase specimen(s) tested positive. Total number of cases, 133.
b
Total number of controls, 642.
c
A kappa correlation of ≥0.75 was considered a good agreement; a correlation of 0.45 to 0.74 was considered a fair agreement, and a correlation of <0.45 was considered a poor agreement.