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. 2023 Feb 20;13(2):e067445. doi: 10.1136/bmjopen-2022-067445

Table 2.

Sample size calculations for secondary objectives

Continuous Mean SD δNI n
ASDAS (N=349) 2.22 1.00 0.90 20
BASDAI (N=564) 4.17 2.24 2.00 20
Pain (VAS) (N=763) 38.33 26.19 20.00 27
Patient global (VAS) (N=687) 40.26 26.07 15.00 38
Physician global (VAS) (N=711) 14.30 16.12 10.00 41
Categorical Proportion δNI n
Overall experience with care (N=276) 0.90 −0.10 141

All values calculated are based on data from SpA-Net retrieved on 29 October 2018. The number of patients with available data is provided in the first column. Stable values are assumed for the standard care group.

ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; n, sample size needed per group; VAS, Visual Analogue Scale (range: 0–100 mm); δNI, non-inferiority limit or margin.