
B

95 % CI lower

95 % CI upper

P


PAL
    
Reference

1.75

1.67

1.83

<0.01

Controls

0.10

0.03

0.18

0.01

Age centered 10 years

0.04

0.02

0.07

<0.01

BMI centered 17 kg/m2

−0.01

−0.02

−0.00

0.04

Gender

−0.07

−0.13

−0.01

0.02

JIA season

−0.14

−0.23

−0.05

<0.01

MVPA
    
Reference

1.70

1.27

2.13

<0.01

Controls

0.41

−0.02

0.83

0.06

Age centered 10 years

0.20

0.07

0.33

<0.01

BMI centered 17 kg/m2

−0.02

−0.08

0.04

0.50

Gender

−0.12

−0.43

0.20

0.47

JIA season

−0.50

−1.00

0.01

0.06

Sedentary time
    
Reference

18.86

18.36

19.37

<0.01

Controls

−0.59

−1.09

−0.09

0.02

Age centered 10 years

−0.13

−0.28

0.03

0.10

BMI centered 17 kg/m2

0.15

0.08

0.21

<0.01

Gender

−0.02

−0.38

0.35

0.92

JIA season

0.78

0.18

1.37

0.01

 The regression equation for PAL is as follows:

\( \begin{array}{l}\mathrm{PAL}\kern0.5em =\kern0.5em \mathrm{reference} + 0.10\ *\ \mathrm{control} + 0.04\ *\mathrm{age}\ \left(\mathrm{centered}\ 10\right) + 0.01\ *\ \mathrm{B}\mathrm{M}\mathrm{I}\ \left(\mathrm{centered}\ 17\right) + 0.07\ \\ {}*\ \mathrm{gender} + 0.14\ *\ \mathrm{season}\end{array} \)
 The reference for this equation is a 10 year old boy with JIA, a BMI of 17 kg/m^{2} of which the data was collected in the summer. So a healthy girl (no JIA) of 8 years old, a BMI of 20 has a predicted PAL of (1.75 + 0,10 * 1 + 0.04 * (8–10) + −0.01 * (20–17) + −0.07 * 1 = 1.73

JIA juvenile idiopathic arthritis, BMI body mass index, PAL physical activity level, MVPA moderate to vigorous activity expressed in hours/day. Sedentary time expressed in hours/day, CI confidence interval of B. Reference category: Boy of 10 years, with a BMI of 17, with JIA, who filled in the diary in the summer period