Table 5 Stratified analysis: by sex, HLA-B27 status and disease duration

No Adjustment for other time variable measures
Outcome	Predictor	Males	P	Females	P	HLA B27+	P	HLA B27−	P	≤ 10yrs	P	> 10yrs	P
BASDAI	Log IPAQ	−0.13 (−0.24, −0.02)	0.016	−0.25 (−0.41, −0.10)	0.001	−0.29 (−0.41, −0.17)	<0.001	0.12 (−0.07, 0.31)	0.2	-0.19 (-0.33, -0.05)	0.008	-0.17 (-0.28, -0.06)	0.003
	IPAQ category	−0.03 (−0.17, 0.11)	0.69	−0.26 (−0.46, −0.06)	0.012	−0.21 (−0.37, −0.05)	0.012	0.08 (−0.20, 0.36)	0.58	-0.11 (-0.28, 0.06)	0.22	-0.12 (-0.27, 0.03)	0.11
	Vigorous activity ≥ 1 hr/week	−0.26 (−0.46, −0.07)	0.007	−0.10 (−0.43, 0.24)	0.57	−0.26 (−0.50, −0.02)	0.037	−0.04 (−0.46, 0.38)	0.84	-0.19 (-0.44, 0.07)	0.15	-0.23 (-0.46, -0.01)	0.04
howRU	Log IPAQ	0.23 (0.11, 0.35)	<0.001	0.15 (−0.04, 0.34)	0.13	0.34 (0.20, 0.48)	<0.001	0.01 (−0.21, 0.22)	0.96	0.20 (0.03, 0.36)	0.019	0.20 (0.07, 0.33)	0.002
	IPAQ category	0.19 (0.04, 0.35)	0.014	0.21 (−0.04, 0.47)	0.1	0.39 (0.20, 0.57)	<0.001	0.09 (−0.24, 0.42)	0.60	0.14 (-0.07, 0.34)	0.2	0.26 (0.08, 0.43)	0.004
	Vigorous activity ≥ 1 hr/week	0.20 (−0.02, 0.42)	0.07	−0.02 (−0.43, 0.40)	0.94	0.13 (−0.16, 0.41)	0.38	−0.10 (−0.59, 0.40)	0.70	-0.18 (-0.48, 0.12)	0.25	0.41 (0.15, 0.68)	0.002
Adjusted for other time variable measures
BASDAI	Log IPAQ	−0.04 (−0.14, 0.05)	0.39	−0.19 (−0.32, −0.06)	0.004	−0.14 (−0.25, −0.04)	0.008	0.12 (−0.05, 0.29)	0.16	-0.11 (-0.23, 0.01)	0.08	-0.09 (-0.19, 0.01)	0.08
	IPAQ category	0.04 (−0.08, 0.17)	0.48	−0.17 (−0.34, 0.00)	0.05	−0.04 (−0.18, 0.10)	0.56	0.11 (−0.14, 0.36)	0.38	-0.06 (-0.21, 0.10)	0.47	-0.01 (-0.15, 0.12)	0.83
	Vigorous activity ≥ 1 hr/week	−0.19 (−0.36, −0.01)	0.034	−0.10 (−0.38, 0.18)	0.47	−0.20 (−0.41, 0.00)	0.06	−0.08 (−0.45, 0.30)	0.68	-0.26 (-0.48, -0.03)	0.025	-0.06 (-0.26, 0.14)	0.55
howRU	Log IPAQ	0.17 (0.06, 0.28)	0.002	−0.02 (−0.19, 0.14)	0.78	0.17 (0.04, 0.29)	0.008	0.06 (−0.13, 0.26)	0.53	0.09 (-0.05, 0.24)	0.21	0.11 (-0.01, 0.22)	0.07
	IPAQ category	0.18 (0.04, 0.32)	0.012	0.04 (−0.18, 0.25)	0.73	0.26 (0.10, 0.43)	0.002	0.13 (−0.17, 0.43)	0.39	0.08 (-0.11, 0.26)	0.42	0.19 (0.04, 0.34)	0.016
	Vigorous activity ≥ 1 hr/week	0.07 (−0.13, 0.27)	0.47	−0.08 (−0.43, 0.27)	0.65	−0.03 (−0.27, 0.22)	0.82	−0.12 (−0.57, 0.33)	0.59	-0.28 (-0.55, -0.01)	0.039	0.28 (0.05, 0.52)	0.016

The Log IPAQ scores given represent METs minutes per week; IPAQ categories consisted of low, medium and high as described in methods. Regression coefficients and the associated 95% confidence intervals are represented along with P values. Time variable measures for adjusted module included howRU or BASDAI as appropriate. Males n = 136 and females n = 87. HLA-B27 positive individuals for Log IPAQ n = 119, and for all other physical activity variables = 120 and HLA negative = 28. Disease duration ≤ 10 years n = 111 and > 10 years n = 112.