Table 6.
Odds ratios of total knee replacement for characteristics at baseline for 106 knee osteoarthritis patients with full follow-up
| Baseline covariate | n | Unadjusted odds ratio (95% CI) | P-value | Adjusted odds ratio (95% CI)a | P-value |
|---|---|---|---|---|---|
| Separated, divorced, widowed | 106 | 1.67 (0.64 to 4.38) | 0.300 | ||
| One ormore comorbidities | 106 | 0.78 (0.32 to 1.91) | 0.580 | ||
| Uses walking stick | 103 | 1.83 (0.82 to 4.32) | 0.142 | ||
| Pain always present | 104 | 1.29 (0.64 to 3.57) | 0.538 | ||
| VAS pain score (0 = no pain to 10 = worse pain) | 103 | 1.33 (1.08 to 1.64) | 0.008 | ||
| WOMAC pain score (0 = no pain to 20 = extreme pain) | 106 | 1.14 (1.01 to 1.28) | 0.038 | ||
| WOMAC physical function score (0 = no difficulty to 68 = extreme difficulty) | 106 | 1.04 (1.00 to 1.07) | 0.049 | ||
| WOMAC stiffness score (0 = no stiffness to 8 = extreme stiffness) | 106 | 1.27 (1.00 to 1.62) | 0.053 | ||
| Oxford Knee Score (12 = least difficulties to 60 =most difficulties) | 105 | 1.06 (1.01 to 1.11) | 0.021 | ||
| SF-36 painb | 106 | 0.99 (0.97 to 1.01) | 0.191 | ||
| SF-36 physical function | 106 | 0.97 (0.94 to 0.99) | 0.004 | 0.96 (0.94 to 0.99) | 0.002 |
| SF-36 role limitation (physical) | 106 | 0.95 (0.91 to 0.99) | 0.019 | ||
| SF-36 role limitation (mental) | 106 | 0.98 (0.96 to 1.01) | 0.196 | ||
a
Forward stepwise final model: likelihood ratio χ2 = 11.62, df = 1, P = 0.001; receiver operating characteristic area under the curve = 0.60, P = 0.092; Nagelkerke pseudo-R2 = 0.15; 15/38 having total joint replacement (TJR) correctly predicted (sensitivity = 39.5%), 50/62 not having TJR correctly predicted (specificity = 80.6%), 65/100 surgical outcomes correctly predicted (correct prediction rate = 65.0%).
b
All SF-36 scores: lower scores indicateworse outcomes. SF-36 = Short Form-36. VAS = visual analogue scale. WOMAC = Western Ontario and McMaster Universities Osteoarthritis Index.