Maxime Verhoeven

100 Chapter 5 Supplementary Table S6 average absolute chance (proportion) of established RA patients with no radiographic progression at baseline per treatment arm, and absolute risk difference between treatment arms. Modifier Group Comparison Relative chance Absolute risk in TCZ+MTX arm (%) Absolute risk in TCZ- monotherapy arm (%) Absolute risk difference (%) Total SvdH scores Baseline joint damage Low tcz vs tcz+mtx 0.99 59 58 1 High tcz vs tcz+mtx 0.86 62 53 9 Baseline disease duration Low tcz vs tcz+mtx 0.83 60 50 10 High tcz vs tcz+mtx 1.04 61 63 2 Baseline DAS28 Low tcz vs tcz+mtx 1.02 57 58 1 High tcz vs tcz+mtx 0.84 64 54 10 Erosion scores Baseline joint damage Low tcz vs tcz+mtx 1 75 75 0 High tcz vs tcz+mtx 0.89 67 60 7 Baseline disease duration Low tcz vs tcz+mtx 0.86 70 60 10 High tcz vs tcz+mtx 1.04 71 74 3 Baseline DAS28 Low tcz vs tcz+mtx 0.96 66 63 3 High tcz vs tcz+mtx 0.99 69 68 1 Joint space narrowing scores Baseline joint damage Low tcz vs tcz+mtx 0.95 75 71 4 High tcz vs tcz+mtx 0.93 61 57 4 Baseline disease duration Low tcz vs tcz+mtx 0.9 69 62 7 High tcz vs tcz+mtx 1 67 67 0 Baseline DAS28 Low tcz vs tcz+mtx 1.02 66 67 1 High tcz vs tcz+mtx 0.82 69 57 12 Number of patients in low level baseline joint damage subgroup; 96 in TCZ vs. 110 in TCZ+MTX, number of patients in high level baseline joint damage subgroup; 105 in TCZ vs. 106 in TCZ+MTX. Number of patients in low level baseline disease duration subgroup; 103 in TCZ vs. 105 in TCZ+MTX, number of patients in high level baseline disease duration subgroup; 99 in TCZ vs. 110 in TCZ+MTX. Number of patients in low level baseline DAS28 subgroup; 103 in TCZ vs. 104 in TCZ+MTX, number of patients in high level baseline DAS28 subgroup; 99 in TCZ vs. 111 in TCZ+MTX. Low= low level subgroup; High= high level subgroup; DAS28= disease activity score assessing 28 joints; TCZ= tocilizumab; MTX= methotrexate. Interpretation: The relative chance of not having radiographic progression of 0.99 for TCZ vs. TCZ+MTX for patients with low baseline joint damage (TCZ vs TCZ+MTX Low) can be translated to an absolute risk difference using the average percentage of patients treated with TCZ+MTX who have no-progression in this group (reference group) of 59%. Using the RR and reference rate of no-progression would be 0.99*59% = 58% for patients treated with TCZ, and the absolute risk difference thus 1%. For patients with high baseline damage, the reference rate of no-progression is 62%, rate of no-progression with TCZ of 0.86*62% = 53%, and an absolute difference of 9%.