Predictive factors of response to treatment: results of the logistic regression in the two study groups*
| Paracetamol (n = 396) | Placebo (n = 365) | |||||
|---|---|---|---|---|---|---|
| Parameter | Odds ratio | 95% CI† | p Values‡ | Odds ratio | 95% CI† | p Values‡ |
| *Response to treatment was defined as a decrease of at least 30% in pain intensity during the 6 weeks of the study (ITT analysis). Patients included in these analyses are all the patients of the ITT population for whom complete data for the independent variables were available; †95% CI, 95% confidence interval; ‡Wald’s test; §MTF, medial tibiofemoral compartment; ¶NR, not relevant. | ||||||
| Sudden increase of pain within the 2 weeks before inclusion | 1.61 | 1.04 to 2.49 | 0.0338 | 1.65 | 1.05 to 2.58 | 0.0297 |
| Morning stiffness (>20 minutes) | 1.64 | 1.05 to 2.54 | 0.0294 | NR | ||
| Pain at night | NR¶ | 1.59 | 1.03 to 2.45 | 0.0370 | ||
| Kellgren and Lawrence radiological score for MTF§ | 0.78 | 0.65 to 0.94 | 0.0081 | NR | ||
| Body mass index (unit = 10 kg/cm2) | 1.68 | 1.10 to 2.56 | 0.0157 | NR | ||
| WOMAC function subscale (unit = 10 points) | 0.88 | 0.76 to 1.02 | 0.0965 | NR | ||
| Patient’s global assessment of knee OA (unit = 10 mm) | NR | 0.88 | 0.78 to 0.99 | 0.0385 | ||
| Aetiology (primary or secondary OA) | NR | 0.51 | 0.22 to 1.15 | 0.1022 | ||