RRR constant | ARR constant | Mixed model | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Placebo event rate(%) | RRR = 50% | RRR = 75% | ARR = 15% | ARR = 25% | Intervention event rate = 5% | ||||||
Patient group | 2 sided | 1 sided | 2 sided | 1 sided | 2 sided | 1 sided | 2 sided | 1 sided | 2 sided | 1 sided | |
Early RA, disease duration <2 years; late RA, disease duration ⩾2 years; RRR, relative risk reduction = (1−(negative event rate intervention group – negative event rate placebo group)×100); ARR, attributive risk reduction = (negative event rate placebo group – negative event rate intervention group); event rate, percentage of patients with progression of joint damage larger than smallest detectable change (SDC) based on the paired Sharp/van der Heijde change-score. | |||||||||||
*ARR 15% or 25% not feasible owing to a placebo event rate smaller then 15%, estimated sample size based on the maximal ARR (9%); †ARR 25% not feasible owing to a placebo event rate smaller then 25%, estimated sample size based on the maximal ARR (20% and 17%). | |||||||||||
Early RA | |||||||||||
Regardless of baseline damage | 9 | 463 | 365 | 172 | 135 | 76* | 60* | 76* | 60* | 151 | 119 |
Medium + high baseline damage, score ⩾4 | 20 | 191 | 151 | 71 | 56 | 75 | 59 | 31† | 24† | 42 | 33 |
High baseline damage, score ⩾21 | 36 | 93 | 73 | 34 | 27 | 138 | 109 | 25 | 20 | 18 | 14 |
Late RA | |||||||||||
Regardless of baseline damage | 17 | 232 | 183 | 86 | 68 | 59 | 46 | 38† | 30† | 54 | 43 |
Medium + high baseline damage, score ⩾4 | 20 | 200 | 157 | 74 | 58 | 71 | 56 | 32† | 26† | 45 | 35 |
High baseline damage, score ⩾21 | 25 | 150 | 118 | 55 | 44 | 97 | 77 | 24 | 19 | 31 | 25 |