Table 2.
Results of multivariable modeling – Baseline biomarker to predict radiographic and pain progression (n=550).
| Imaging Biomarkers Only | Imaging + Biochemical Biomarkers | |||||
|---|---|---|---|---|---|---|
| MODEL | M1 | M2 | M3* | M4 | M5** | M6* |
| Selection Method | Stepwise, AIC | Stepwise, SBC | Stepwise, P-value | Stepwise, AIC | Stepwise, SBC | Stepwise, P-value |
| Model characteristics | ||||||
| AUC (unadjusted) | 0.684 | 0.646 | 0.684 | 0.688 | 0.646 | 0.684 |
| AUC (adjusted)*** | 0.718 | 0.688 | 0.718 | 0.722 | 0.688 | 0.718 |
| AUC (adjusted, 10 fold cross-validation) | 0.669 | 0.641 | 0.669 | 0.671 | 0.641 | 0.669 |
| IDI | 0.0832 | 0.0548 | 0.0832 | 0.0861 | 0.0548 | 0.0832 |
| NRI | 0.4746 | 0.4048 | 0.4746 | 0.5007 | 0.4048 | 0.4746 |
| %cases correctly reclassified1 | 28% | 29% | 28% | 28% | 29% | 28% |
| %controls correctly reclassified2 | 19% | 12% | 19% | 22% | 12% | 19% |
| Biomarkers Included | ||||||
| Semi-quantitative Hoffa-synovitis score | 0.0467 | 0.0467 | 0.0682 | 0.0467 | ||
| 0 | REF | REF | REF | REF | ||
| 1 | 1.67 (1.09, 2.56) | 1.67 (1.09, 2.56) | 1.61 (1.05, 2.48) | 1.67 (1.09, 2.56) | ||
| 2–3 | 1.87 (0.86, 4.05) | 1.87 (0.86, 4.05) | 1.83 (0.84, 3.95) | 1.87 (0.86, 4.05) | ||
| Quantitative mean cartilage thickness - central lateral femur (internal) [mm] z-score | 0.0374 | 0.0374 | 0.0374 | 0.0374 | ||
| OR for each 1 unit increase in SD | 1.29 (1.02, 1.65) | 1.29 (1.02, 1.65) | 1.29 (1.02, 1.65) | 1.29 (1.02, 1.65) | ||
| Quantitative mean cartilage thickness - central medial femur (external) [mm] (z-score) | 0.0013 | 0.0013 | 0.0010 | 0.0013 | ||
| OR for each 1 unit increase in SD | 0.65 (0.50, 0.85) | 0.65 (0.50, 0.85) | 0.65 (0.50, 0.84) | 0.65 (0.50, 0.85) | ||
| Number of locations affected by any osteophyte (semi-quantitative) | 0.0008 | <.0001 | 0.0008 | 0.0008 | <.0001 | 0.0008 |
| 0–2 | REF | REF | REF | REF | REF | REF |
| 3–5 | 1.92 (0.92, 4.02) | 1.92 (0.93, 3.95) | 1.92 (0.92, 4.02) | 1.99 (0.95, 4.18) | 1.92 (0.93, 3.95) | 1.92 (0.92, 4.02) |
| 6+ | 3.47 (1.72, 7.02) | 3.94 (1.99, 7.78) | 3.47 (1.72, 7.02) | 3.55 (1.75, 7.22) | 3.94 (1.99, 7.78) | 3.47 (1.72, 7.02) |
| Patella shape (vector) (z-score) | 0.0028 | 0.0015 | 0.0028 | 0.0029 | 0.0015 | 0.0028 |
| OR for each 1 unit increase in SD | 0.72 (0.58, 0.89) | 0.71 (0.58, 0.88) | 0.72 (0.58, 0.89) | 0.72 (0.59, 0.90) | 0.71 (0.58, 0.88) | 0.72 (0.58, 0.89) |
| Serum NTX-I**** | 0.1197 | |||||
| OR for each 1 unit increase in SD | 1.16 (0.96, 1.41) | |||||
P value and OR (95% CI) are presented in the table for the individual biomarkers.
The biomarkers selected were the same as model 1.
The biomarkers selected were the same as model 2.
Adjusted for age, BMI, sex, race, baseline minimum joint space width, baseline WOMAC pain score, baseline KLG and use of pain medications
Interpolated research value if below lower limit
IDI = integrated discrimination improvement
NRI = category-less net reclassification; 1: %cases correctly reclassified = % of cases with a higher probability of being a case in new model vs. old; 2: %controls correctly reclassified = % of controls with a lower probability of being a case in new model vs. old;