Table 1.

Demographic and clinical characteristics for entire sample and according to amount of pain relief expected (N=422)

Characteristic	Entire sample (N=422)	According to amount of pain relief expected
		Complete (n=190)	A lot (n=185)	Moderate (n=40)	A little (n=7)
Age, years (mean±SD)	56±15	56±15	56±15	56±14	50±17
Men	55%	59%	49%	63%	71%
Employed full time	36%	42%	32%	35%	0%*
Workman compensation	10%	7%	10%	26%	29%ʈ
Non-work related accident	18%	19%	17%	15%	14%
Lawsuit pending	4%	3%	4%	3%	14%
Depressive symptoms, score a (mean±SD)	10±7	9±7	10±8	11±7	14±9
positive screen for depression	38%	33%	41%	48%	57%*
Anxiety symptoms, score b (mean±SD)	40±12	39±12	41±13	42 ±10	43±13
more anxiety than population norms	60%	54%	63%	73%	57%*
Major medical comorbidity	29%	25%	35%	18%	43%
Diagnosis
acute herniated disc	22%	27%	19%	10%	14%
degenerative disease c	78%	73%	81%	90%	86%¶
Symptoms > 6 months	79%	77%	80%	85%	86%
Disability due to back pain, score d (mean±SD)	56%± 14%	56%±15%	56%±13%	57%±17%	60%±12%
Revision surgery	21%	15%	23%	30%	57%ʈ
Narcotics	44%	40%	45%	53%	86%*
Epidural corticosteroids	76%	73%	76%	83%	86%
Vertebral levels involved
L1	11%	7%	16%	10%	14%
L2	25%	20%	30%	33%	14%
L3	42%	42%	42%	50%	29%
L4	73%	75%	70%	78%	57%
L5	61%	60%	62%	65%	43%
Spine fusion (lateral or interbody)	38%	34%	44%	43%	29%
Required subsequent surgery within 2 years	15%	12%	16%	25%	43%¶

^abased on Geriatric Depression Scale, possible range 0–30, higher is more depressive symptoms, ≥ 11 is positive screen for depression

^bbased on Spielberg State Anxiety Inventory, possible score 20 – 80, higher is more anxiety

^cspondylolisthesis, stenosis, disc disease

^dbased on Oswestry Disablity Index, possible range 0–100%, higher is more disability

^*p ≤ .05;

^¶p ≤ .01;

^ʈp ≤ .001