Table 1.

Demographics, pain, and mood parameter differences between healthy controls (CON), SBP, and CBP, at baseline

	SBP N = 160	CBP N = 32	CON N = 35	F‐value (P)
Education (years)	14.2 ± 0.197	13.8 ± 0.428	15.1 ± 0.533	1.92 (0.149)
Income (bracket)	2.55 ± 0.1	2.34 ± 0.2	2.92 ± 0.2	1.98 (0.141)
PANAS (+)	33.2 ± 0.688	31.1 ± 1.52	35.3 ± 1.5	1.35 (0.261)
PANAS (−)	17.9 ± 0.556	20.5 ± 1.24	13.2 ± 0.73	11.4 (2 e − 5)*
BDI	6.83 ± 0.434	8.65 ± 0.932	2.2 ± 0.539	13.3 (4 e − 6)*
MPQa	2.92 ± 0.240	4.28 ± 0.530	—	4.48 (0.036)
MPQs	13.4 ± 0.49	14.2 ± 0.893	—	0.451 (0.503)
Radiculopathy	5.38 ± 0.178	5.78 ± 0.536	—	0.752 (0.387)
pDetect	12.5 ± 0.575	13.8 ± 0.972	—	0.790 (0.375)
NPS	46.1 ± 1.24	47.1 ± 2.76	—	0.0160 (0.900)
PDI	27.7 ± 1.12	31.6 ± 1.90	—	2.52 (0.114)

Clinical characteristics are shown as mean ± s.e.m, determined at baseline. *Corrected P < 0.05. Uncorrected P‐values are shown. Of the 32 CBP at entry 14 were female and group mean age was 45.1 ± 1.3 (s.e.m.). Of the 35 CON at entry 20 were female and group mean age was 36.2 ± 1.3 (s.e.m). Of the 160 SBP subjects, 80 were female, and group mean age was 42.06 ± 0.86 (s.e.m.); pain duration in weeks at baseline: 8.87 ± 4.5 (s.d.).