Table 3

Correlations between daily physical activity and clinical assessments in patients with ankylosing spondylitis

IPAQ (MET-minutes/week)

SQUASH

Accelerometer (kcounts/day)


Number of patients

86a

94a

55b

Disease activity

BASDAI (range 0 to 10)c

-0.220*d

-0.326**d

NS

ESR (mm/hour)c

NS

NS

-0.460***d

CRP (mg/l)c

NS

NS

-0.289*d

ASDASCRPc

-0.243*d

-0.311**d

-0.283*d

Physical function

BASFI (range 0 to 10)c

-0.387***d

-0.476***e

-0.274*e

Spinal mobility

Occiput-to-wall distance (cm)c

NS

-0.297**d

NS

Chest expansion (cm)f

NS

NS

NS

Modified Schober test (cm)f

NS

0.260*d

0.338*d

Lateral spinal flexion (cm)f

NS

NS

0.369*e

Cervical rotation (degrees)f

NS

0.306**d

0.320**d

Quality of life

ASQoLc

-0.282**d

-0.500***d

-0.356**d


ASDAS, ankylosing spondylitis disease activity score; ASQoL, ankylosing spondylitis quality of life; BASDAI, Bath ankylosing spondylitis disease activity index; BASFI, Bath ankylosing spondylitis functional index; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; IPAQ, International Physical Activity Questionnaire; MET, metabolic equivalent; NS, nonsignificant; SQUASH, Short QUestionnaire to Assess Health-enhancing physical activity. aOnly patients with complete data on the first IPAQ or SQUASH assessment and available clinical data were included. bOnly patients with complete accelerometer data and available clinical data were included. cLower score represents lower disease activity or better physical function, spinal mobility or quality of life.dSpearman's correlation coefficient. ePearson's correlation coefficient. fHigher score represents better spinal mobility. *Statistically significant correlation (P < 0.05). **Statistically significant correlation (P < 0.01). ***Statistically significant correlation (P < 0.001).

Arends et al. Arthritis Research & Therapy 2013 15:R99   doi:10.1186/ar4279

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