Table 3.

Correlations between 6MWD, TUG time, and general-, disease- and organ-specific variables in patients. Values are Pearson correlation coefficient unless otherwise specified.

Variable	r
Variable	6MWD	TUG
General
Sex	0.21	−0.06
Age, yrs	−0.16	0.28^*
Weight	−0.02	0.17
Height	0.29^*	0.01
BMI	−0.27^*	0.30^*
No. cigarettes daily^†	−0.28	0.13
Physical activity ≥ 2–3 h/week	0.21	−0.16
Physical activity frequency ≥ 2–3×/week	0.23	−0.14
SF-36 PCS	0.64^***	−0.69^***
Disease-specific variables
ESR	−0.37^**	0.35^**
CK^†	0.25	−0.23
Inactive disease PRINTO	0.37^**	−0.29^*
Disease duration	−0.12	0.25
Diagnosis before/after 1990	0.02	0.08
Use of prednisolone or DMARD	−0.26	0.11
Cum prednisolone dose^†	−0.17	0.24
DAS total	−0.33^*	0.32^*
DAS muscle^†	−0.45^***	0.47^***
DAS skin	−0.03	−0.04
MyoAct^†	−0.35^**	0.32^*
MITAX^†	−0.24	0.33^*
Calcinosis	0.11	0.09
Joint contractures	−0.05	0.27^*
MDI total	−0.19	0.31^*
CHAQ/HAQ^†	−0.42^**	0.39^**
Muscle
MMT^†	0.41^**	−0.30^*
CMAS^†	0.58^***	−0.51^***
MRI thigh pathology	−0.26	0.29^*
Lung
Low DLCO	−0.28^*	−0.18
Low TLC	−0.02	−0.20
Low FVC	−0.30^*	0.38^**
HRCT pathology	−0.33^*	0.41^**
Heart
Long axis strain	0.00	−0.19
E/É	−0.18	0.16
ECG pathology	0.27^*	−0.08
Systolic blood pressure	−0.16	0.22
Diastolic blood pressure	−0.25	0.35^**

↵* p < 0.05.
↵** p < 0.01.
↵*** p < 0.001.
↵† Spearman ρ. 6MWD: 6-min walk distance; TUG: timed up and go; BMI: body mass index; SF-36 PCS: Medical Outcomes Study Short Form-36 physical component summary; ESR: erythrocyte sedimentation rate; CK: creatinine kinase; PRINTO: Pediatric Rheumatology International Trials Organization; DMARD: disease-modifying antirheumatic drugs; DAS: Disease Activity Score; MyoAct: Myositis Disease Activity Assessment Visual Analogue scales; MITAX: Myositis Intention to Treat Activity Index; MDI: Myositis Damage Index; CHAQ/HAQ: child/adult Health Assessment Questionnaire; MMT: unilateral manual muscle test; CMAS: Childhood Myositis Assessment Score; MRI: magnetic resonance imaging; TLC: total lung capacity; FVC: forced vital capacity; HRCT: high-resolution computed tomography; E/É: early diastolic transmitral flow/early diastolic tissue velocity; ECG: electrocardiography; Low DLCOc/TLC/FVC: percentage predicted less than the fifth percentile of DLCO, corrected for hemoglobin, TLC, or FVC.