Personal factors
In general, ODI scores showed an increasing trend with age, BMI
category, and smoking and alcohol use (Table 4). Results of the
stepwise regression showed that a model with an adjusted R2 of
0.21 with the main effects of age, family history, physical activity,
alcohol and smoking significantly predicted ODI ratings (Table 5).
Only the interaction effect of family history with physical activity
was included in the model (Table 5).
Smoking was included first in the model and had an adjusted R2
of 0.12 i.e., smoking explained 12% of the variance. Alcohol
explained 5%, age 5% and the interaction term explained 7% of the
variance in the model predicting LBP severity