Development of subset assessment of candidate improvement criteria for anti-TNFα agents in ankylosing spondylitis on the basis of the six domains: pain, patient global, function, inflammation, spinal mobility, and C reactive protein, modified by exchange of certain domains and instruments
Criterion | Improvement definition | Infliximab trial (n = 69) | Combined dataset etanercept and infliximab trial (n = 69) (χ2) | |||
---|---|---|---|---|---|---|
Per cent improving in the placebo treated group (n = 35) | Per cent improving in the infliximab treated 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 = 98 at random. | ||||||
*Candidate criteria with χ2 values that are not significantly below reference criterion 1 (table 2). | ||||||
AS, ankylosing spondylitis; BASMI, Bath ankylosing spondylitis metrology index; CI, confidence interval. | ||||||
Five domains including the BASDAI instead of pain and inflammation | ||||||
21 | ⩾20%/10 units change in any four of five domains | 5.71 | 67.64 | 28.63* | 4.25 to 18.69 | 22.04 |
22 | ⩾20% change in any four of five | 5.71 | 67.65 | 28.63* | 14.34 to 44.36 | 23.22 |
23 | ⩾20% change in any four of five, including BASDAI | 5.71 | 67.64 | 28.63* | 14.34 to 44.36 | 23.22 |
24 | ⩾40%/20 units change in any three of five | 5.71 | 58.82 | 22.40* | 9.05 to 32.53 | 24.72 |
25 | ⩾40% change in any three of five | 5.71 | 64.71 | 26.46* | 12.97 to 40.72 | 27.40 |
26 | ⩾40% in 3 of 5 or ⩾30% in four of five, including BASDAI | 2.86 | 64.71 | 29.69* | 16.61 to 43.92 | 23.43 |
Five domains for improvement in AS without the domain acute phase reactants | ||||||
27 | ⩾20%/10 units change in any four of five domains | 8.57 | 73.52 | 30.18* | 16.13 to 46.18 | 25.88 |
28 | ⩾20% change in any four of five | 8.57 | 76.47 | 32.63* | 17.26 to 48.41 | 25.43 |
29 | ⩾20% change in any four of five, including pain | 8.57 | 76.47 | 32.63* | 17.26 to 48.41 | 25.43 |
30 | ⩾40%/20 unit change in any three of five domains | 8.57 | 64.71 | 23.52* | 11.25 to 37.87 | 18.69 |
31 | ⩾40% change in any three of five | 8.57 | 67.65 | 25.63* | 12.72 to 40.36 | 20.96 |
32 | ⩾40% in three of five or ⩾30% in four of five, including pain | 8.57 | 64.71 | 23.52* | 10.88 to 38.20 | 19.80 |
Six domains for improvement in AS with an exchange of BASMI for lateral lumbar flexion | ||||||
33 | ⩾20%/10 unit change in any five of six domains | 0.0 | 58.82 | 28.99* | 17.81 to 42.36 | 25.62 |
34 | ⩾30%/10 unit change in any four of six | 5.71 | 64.71 | 26.46* | 13.86 to 41.11 | 20.84 |
35 | ⩾40%/20 unit change in any three of six | 8.57 | 67.65 | 25.63* | 12.72 to 40.36 | 19.94 |
36 | ⩾20% change in any five of six | 14.29 | 76.47 | 26.95* | 13.22 to 43.41 | 28.03 |
37 | ⩾30% change in any four of six | 5.71 | 61.76 | 24.38* | 12.27 to 38.43 | 22.33 |
38 | ⩾40% change in any three of six | 11.43 | 70.59 | 25.03* | 11.79 to 40.52 | 29.24 |