Table 2

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

		Age, years			Lumbar BMD			Weight, kg			Exercise (yes)
Dependent variable	Model R²	R² increment	β	r	R² increment	β	^r†	R² increment	β	^r†	R² increment	β	^r†
Disc height	0.154	0.130	0.386^***	0.365^***	0.030	0.196^***	0.240^***	0.005	0.075^*	0.132^***	0.006	0.075^*	0.083^*
Disc signal	0.303	0.262	0.549^***	0.552^***	0.004	0.072^*	0.164^***	0.017	0.142^***	0.193^***	0.001	0.024	0.039
Disc bulge	0.109	0.106	0.348^***	0.337^***	0.016	0.146^***	0.155^***	0.001	0.029	0.094^**	0.002	0.044	0.058
Anterior osteophytes	0.111	0.101	0.341^***	0.315^***	0.012	0.127^**	0.158^***	0.000	0.019	0.075^*	0.011	0.106^**	0.112^**
LDD summary score	0.285	0.258	0.544^***	0.519^***	0.022	0.168^***	0.247^***	0.009	0.100^**	0.176^***	0.006	0.075^*	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.