Relationship between smoking, clinical, inflammatory, and radiographic parameters in patients with ankylosing spondylitis

Egyptian Rheumatology and Rehabilitation

Table 3 Correlation between smoking index for current smokers (pack-year) with other parameters in the AS study groups

Parameters	Smoking index for current smokers (pack-year)
Parameters	r value	P value
ESR (mm/h)	−0.181	0.432
CRP (mg/l)	−0.104	0.653
Schober test (cm)	−0.049	0.832
Chest expansion (cm)	−0.593	0.005*
Occipt to wall distance (cm)	0.317	0.161
BASDAI	0.320	0.158
BASFI	0.568	0.007*
ASDAS	0.396	0.046*
mSASSS	0.584	0.005*

Pearson’s correlation coefficient (r) test was used to assess the degree of association between two sets of variables
BASDAI Bath Ankylosing Spondylitis Disease Activity Index, BASFI Bath Ankylosing Spondylitis functional index, ASDAS Ankylosing Spondylitis Disease Activity Score, mSASSS modified Stoke Ankylosing Spondylitis Spine Score, ESR erythrocyte sedimentation rate, CRP C-reactive protein