Table 3. Raw agreement indices among conventional culture/PCR method and real-time PCR assay, with two-step enrichment procedure for detection of S. aureus from animals and retail meat.
| Comparison within each sample type | No. of samples | No. positive by culture/PCR method | No. (%) of samples* | kappa statistic | ||
| Positive agreement (Sensitivity) | Negative agreement (Specificity) | Total agreement | ||||
| Real-time PCR primary enrichment | ||||||
| Animals | 77 | 32 | 32 (100.0) | 34 (75.6) | 66 (85.7) | 0.72 |
| Meat | 112 | 58 | 52 (89.7) | 42 (77.8) | 94 (83.9) | 0.68 |
| Deli meat | 45 | 5 | 4 (80.0) | 40 (100.0) | 44 (97.8) | 0.88 |
| Real-time PCR secondary enrichment | ||||||
| Animals | 77 | 32 | 32 (100.0) | 36 (80.0) | 68 (88.3) | 0.77 |
| Meat | 112 | 58 | 52 (89.7) | 46 (85.2) | 98 (87.5) | 0.75 |
| Deli meat | 45 | 5 | 5 (100.0) | 26 (65.0) | 31 (68.9) | 0.29 |
*Percentages for positive agreement with culture/PCR method number positive as the denominator. Percentages for negative agreement with culture/PCR method number negative as the denominator. Percentage total agreement is obtained from the sum of the positive and negative agreement frequencies divided by the total sample size within each sample type.