Table 2 Multinomial logistic regression model estimating the predictive effect (OR and 95% CI) of levels of BMI and levels of physical work load on the development of low back pain

Low back pain 1–7 days

BMI

Physical work load

Normal

Overweight

Obese

Low

Moderate

High

Model I ^a

Ref.

0.95/|0.59-1.51|

0.91/|0.50-1.68|

Ref.

1.43/|0.85-2.39|

2.02*/|1.23-3.33|

Model II ^b

Ref.

1.05/|0.65-1.70|

0.92/|0.49-1.73|

Ref.

1.25/|0.74-2.12|

1.78*/|1.06-2.98|

Low back pain over 7 days

BMI

Physical work load

Normal

Overweight

Obese

Low

Moderate

High

Model I ^a

Ref.

1.07/|0.72-1.60|

0.81/|0.46-1.42|

Ref.

1.35/|0.85-2.13|

2.16*/|1.39-3.34|

Model II ^b

Ref.

1.09/|0.72-1.65|

0.79/|0.45-1.41|

Ref.

1.18/|0.74-1.89|

1.78*/|1.13-2.80|