Table 2

LDD traits and summary score with risk factors: multivariate multiple regression analysis (for entire model, multiple p<0.0001)

Age, yearsLumbar BMDWeight, kgExercise (yes)
Dependent variableModel R2R2 incrementβrR2 incrementβr†R2 incrementβr†R2 incrementβr†
Disc height0.1540.1300.386***0.365***0.0300.196***0.240***0.0050.075*0.132***0.0060.075*0.083*
Disc signal0.3030.2620.549***0.552***0.0040.072*0.164***0.0170.142***0.193***0.0010.0240.039
Disc bulge0.1090.1060.348***0.337***0.0160.146***0.155***0.0010.0290.094**0.0020.0440.058
Anterior osteophytes0.1110.1010.341***0.315***0.0120.127**0.158***0.0000.0190.075*0.0110.106**0.112**
LDD summary score0.2850.2580.544***0.519***0.0220.168***0.247***0.0090.100**0.176***0.0060.075*0.101**
Multiple p value<0.0001<0.0001<0.0001<0.0001
  • R2 increment was calculated as squared semipartial correlation; this reflects the drop in R2 of the model if a particular predictor had been excluded from the model, with the rest of predictors remaining in the model.

  • Statistically significant terms (p<0.05, at least) are shown in bold, specifically:

  • * p value <0.05;

  • ** p value <0.01;

  • *** p value <0.001.

  • R is the Pearson correlation between raw LDD traits and age;

  • r† is the Pearson correlation between the variables adjusted for age only.

  • BMD, body mineral density; LDD, lumbar degenerative disc disease.