Summary performance estimates given for the independent significant covariate, prevalence. Also given are the estimates of sensitivity for each level of the covariate x-ray group, which was significant for the dependent variable logit (sensitivity)
| Model estimates of performance characteristics in significant covariates | ||
| High prevalence | Low prevalence | |
| Sensitivity (%) | ||
| Soft tissue x-rays | 93.7 (79.5 to 98.3) | 68.3 (44.3 to 85.3) |
| Appendicular x-rays | 97.3 (93.3 to 99.0) | 84.0 (70.3 to 92.2) |
| Axial skeletal x-rays | 58.6 (17.3 to 90.5) | 17.0 (2.4 to 63.1) |
| Summary | 95.8 (91.1 to 98.1) | 78.3 (65.7 to 87.2) |
| Specificity (%) | ||
| Summary | 56.0 (41.9 to 69.2) | 92.3 (90.0 to 94.2) |
| Positive likelihood ratio | ||
| Summary | 2.2 (1.6 to 3.0) | 10.2 (7.6 to 13.8) |
| Negative likelihood ratio | ||
| Summary | 0.07 (0.03 to 0.17) | 0.23 (0.14 to 0.38) |
| Diagnostic Odds ratio | ||
| Summary | 37.3 (3.6 to 101.3) | 36.1 (21.0 to 62.3) |
All estimates are derived from the hierarchical regression model and take into account variation in performance between individual doctors and different x-ray groups. The covariate x-ray group has three levels: soft tissue (chest and abdominal x-rays), appendicular (limbs, hands and feet) and axial (skull, spine and sacrum). Interaction terms were not significant. 95% CIs are shown in brackets.