Table 5.

Percentage of models in which a variable was statistically significant; percentage of models in which a variable had a positive coefficient sign; and percentage of models in which a variable had a negative coefficient sign for the covariates present in the extended Cox models fitted for data sets A, B, C, and D; and average of those percentages across all data sets.

Variable	Data set															Average
	A			B			C				D
	ssa	posb	negc	ss	pos	neg	ss	pos	neg	ss		pos	neg	ss			pos	neg
Male (ref: female)	N/Ad	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0		25	75	0			25	75
Year of disease onset	N/A	N/A	N/A	N/A	N/A	N/A	100	100	0	N/A		N/A	N/A	100			100	0
Year of biologic therapy initiation	100	100	0	100	100	0	N/A	N/A	N/A	N/A		N/A	N/A	100			100	0
Age at start of the first biologic therapy	86	0	100	N/A	N/A	N/A	N/A	N/A	N/A	N/A		N/A	N/A	86			0	100
Disease years until start of the first biologic therapy	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0		0	100	0			0	100
HLA-B27e	N/A	N/A	N/A	N/A	N/A	N/A	86	0	100	N/A		N/A	N/A	86			0	100
Years of education	100	100	0	100	100	0	N/A	N/A	N/A	75		100	0	92			100	0
Baseline CRPf	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	40		80	20	40			80	20
Baseline BASFIg	50	100	0	50	100	0	0	50	50	50		100	0	38			88	13
CRP	0	100	0	50	100	0	0	100	0	100		100	0	38			100	0
ESRh	0	100	0	100	100	0	100	100	0	100		100	0	75			100	0
BASDAIi	100	100	0	100	100	0	100	100	0	100		100	0	100			100	0
BASFI	33	100	0	67	100	0	33	100	0	100		100	0	58			100	0
ASDASj	100	100	0	100	100	0	100	100	0	100		100	0	100			100	0

^ass: percentage of models in which variable is statistically significant.

^bpos: percentage of models in which variable has positive coefficient.

^cneg: percentage of models in which variable has negative coefficient.

^dN/A: not applicable.

^eHLA-B27: human leukocyte antigen B27.

^fCRP: C-reactive protein.

^gBASFI: Bath Ankylosing Spondylitis Functional Index.

^hESR: erythrocyte sedimentation rate.

ⁱBASDAI: Bath Ankylosing Spondylitis Disease Activity Index.

^jASDAS: Ankylosing Spondylitis Disease Activity Score.