Table 1.
Validation of the Digital Arthritis Index (DAI) in three independent experiments.
| Experiment 1 | Experiment 2 | Experiment 3 | ||||
|---|---|---|---|---|---|---|
| CIA | Control | CIA | Control | CIA | Control | |
| Digital Arthritis Index (DAI) | ||||||
| Incidence | 100% (9 of 9) | 0% (0 of 9) | 100% (7 of 7) | 0% (0 of 7) | 100% (16 of 16) | 0% (0 of 4) |
| Onset | 13.3 ± 1.7 | N/A | 13.0 ± 0.6 | N/A | 12.6 ± 0.9 | N/A |
| Severity | 9.7 ± 1.8∗ | 3.1 ± 1.2 | 10.5 ± 1.6∗ | 4.1 ± 1.3 | 9.5 ± 1.4∗ | 0.8 ± 0.6 |
| Joint size | ||||||
| Incidence | 100% (9 of 9) | 0% (0 of 9) | 100% (7 of 7) | 0% (0 of 7) | 100% (16 of 16) | 0% (0 of 4) |
| Onset | 12.8 ± 1.3 | N/A | 14.6 ± 0.8∧ | N/A | 13.0 ± 1.2 | N/A |
| Δ Size (in) | 0.11 ± 0.03∗ | 0.01 ± 0.009 | 0.07 ± 0.03∗ | -0.007 ± 0.02 | 0.12 ± 0.02∗ | 0.005 ± 0.03 |
| Arthritis score | ||||||
| Incidence | 100% (9 of 9) | 0% (0 of 9) | 71% (5 of 7) | 0% (0 of 7) | 94% (15 of 16) | 0% (0 of 4) |
| Onset | 13.7 ± 1.6 | N/A | 14.8 ± 0.8∧ | N/A | 14.2 ± 1.4∧ | N/A |
| Severity | 7.2 ± 1.3∗ | 2.0 ± 0 | 5.6 ± 1.9∗ | 0 | 7.1 ± 1.3∗ | 0 |
| Histopathology | ||||||
| Score | 7.4 ± 2.8∗ | 0.14 ± 0.25 | 8.8 ± 2.6∗ | 0 | 10.8 ± 2.4∗ | 0 |
Disease incidence, onset, and severity for CIA and control rats were calculated using the DAI, ankle joint size measurements, and arthritis scores. Values represent means ± std. ∗P ≤ 0.001 vs. control, ∧P ≤ 0.05 vs. DAI onset.