Sensitivity of means and standard deviations for extreme radiographic progression scores: an example from the COBRA* trial
| Mean one year radiographic progression | SD (or 95% CI)of mean one year radiographic progression | |
|---|---|---|
| *The COBRA trial is a randomised controlled trial comparing intensive step down combination therapy including temporary high dose prednisolone with sulfasalazine monotherapy. | ||
| All patients included | ||
| Control group | 11.9 | 12.6 |
| COBRA group | 7.2 | 10.2 |
| Between group difference | 4.7 | 0.8 to 8.6 |
| 10% highest progression scores excluded | ||
| Control group (as a percentage of all patients) | 8.4 (−29%) | 7.2 (−45%) |
| COBRA group | 4.4 (−39%) | 5.4 (−47%) |
| Between group difference | 4.0 | 1.6 to 6.3 |