Variable	Sample (n = 24)
Age: mean (SD)	50.5 (13.2)
Sex (males)	10 (42%)
Body Mass Index: mean (SD)	27.6 (5.6)
Living status (lives alone)	6 (25%)
Education (post-secondary or greater)	18 (75%)
Smoking status (current smoker)	6 (25%)
Current disability or insurance claims (yes)	6 (24%)
Number of comorbidities: mean (SD)	3.0 (2.3)
Pre-operative daily opiate use (yes)	9 (38%)
Duration of symptoms:
Less than 3 months	2 (8%)
3 to 6 months	0 (0%)
6 to 12 months	1 (4%)
1 to 2 years	2 (8%)
Greater than 2 years	19 (79%)
Pre-operative Patient-Reported Outcome Measures
Numerical Pain Rating Scale - back pain: mean (SD)	7.1 (2.0)
Oswestry Disability Index: mean (SD)	43.7 (17.5)
Short Form 12 - Physical Component Summary	32.5 (9.7)
Short Form 12 - Mental Component Summary	47.3 (7.0)
Patient Health Questionnaire	11.3 (6.6)

SD = Standard Deviation.