Development of subset assessment of candidate improvement criteria for anti-TNFα agents in ankylosing spondylitis on the basis of the six domains of pain, patient global, function, inflammation, spinal mobility, and C reactive protein
Criterion | Improvement definition | Infliximab trial (n = 69) | Combined dataset of etanercept and infliximab trials (n = 69) (χ2) | |||
---|---|---|---|---|---|---|
Per cent improving in placebo group (n = 35) | Per cent improving in infliximab group (n = 34) | χ2 | 95% CI of the χ2 value | |||
Columns 3–7: infliximab trial, week 12. Last column: data from the combined dataset at week 6; to be comparable, n = 69 from n = 99 at random. The criteria that performed best are shown in bold. | ||||||
*Candidate criteria with χ2 values that are not statistically significant below reference criterion 1. | ||||||
†Placebo response significantly above 10%. | ||||||
CI, confidence interval. | ||||||
Relative improvement | ||||||
1 | ⩾20% change in any five of six domains | 2.86 | 67.65 | 31.91* | 18.02 to 46.94 | 27.43 |
2 | ⩾30% change in any five of six | 2.86 | 50.00 | 19.88 | 9.05 to 32.53 | 15.89 |
3 | ⩾40% change in any five of six | 2.86 | 44.12 | 16.48 | 6.99 to 27.81 | 15.95 |
4 | ⩾30% change in any four of six | 5.71 | 64.71 | 26.46* | 13.86 to 41.11 | 20.44 |
5 | ⩾40% change in any four of six | 5.71 | 61.76 | 24.38* | 11.52 to 39.20 | 23.09 |
6 | ⩾50% change in any four of six | 5.71 | 52.94 | 18.69 | 7.93 to 32.38 | 19.48 |
7 | ⩾30% change in any three of six | 22.86† | 73.53 | 17.75 | 4.96 to 34.02 | 25.88 |
8 | ⩾40% change in any three of six | 8.57 | 67.65 | 25.63* | 12.72 to 40.36 | 22.35 |
9 | ⩾50% change in any three of six | 8.57 | 61.76 | 21.51* | 9.51 to 36.91 | 21.95 |
Relative and absolute improvement | ||||||
10 | ⩾20%/10 units change in any five of six domains | 2.86 | 64.71 | 29.69* | 16.26 to 44.25 | 27.72 |
11 | ⩾30%/10 units change in any five of six | 2.86 | 47.06 | 18.15 | 7.90 to 30.34 | 15.89 |
12 | ⩾40%/20 units change in any five of six | 0.0 | 38.24 | 16.49 | 8.53 to 26.67 | 15.78 |
13 | ⩾30%/10 units change in any four of six | 5.71 | 64.71 | 26.46* | 13.86 to 41.11 | 20.84 |
14 | ⩾40%/20 units change in any three of six | 8.57 | 67.65 | 25.63* | 12.72 to 40.36 | 22.64 |
15 | ⩾50%/20 units change in any three of six | 8.57 | 58.82 | 19.60* | 8.32 to 33.75 | 21.95 |
16 | ⩾60%/30 units change in any three of six | 0.0 | 47.06 | 21.44* | 11.91 to 32.53 | 17.04 |
Relative improvement including pain | ||||||
17 | ⩾20% change in any five of six domains, including pain | 2.86 | 67.65 | 31.91* | 18.02 to 46.94 | 27.43 |
18 | ⩾40% change in any four of six, including pain | 5.71 | 58.82 | 22.40* | 10.14 to 36.96 | 23.09 |
Combinations in relative improvement | ||||||
19 | ⩾40% in four of six domains or ⩾30% in five of six | 5.71 | 61.76 | 24.38* | 11.52 to 39.20 | 20.69 |
20 | ⩾50% in four of six or ⩾30% in five of six | 5.71 | 58.82 | 22.40* | 10.14 to 36.71 | 20.69 |