Table 3.

NDI validity study

	Mean ± SD	Correlations with NDI
VAS Pain	61.5 ± 25	0.60*
VAS Disability	51.2 ± 29	0.76**
HAD depression	7.3 ± 4.2	0.62*
HAD Anxiety	9.7 ± 4.5	0.58*
SF-36
Physical functioning	62.5 ± 24.3	0.68*
Role Physical	31.2 ± 24.3	0.29
Bodily Pain	39.4 ± 21.5	0.42ϕ
General health	48.1 ± 18.9	0.55*
vitality	49.2 ± 23.1	0.57*
Social functioning	60.2 ± 18.2	0.64*
Role Emotional	37.1 ± 19.9	0.36ϕ
Mental health	57.2 ± 21.2	0.60*