Baseline characteristics stratified by presence of disabling back pain.

Values are n (%) or means ± SD.||Body-mass index (BMI) is the weight in kilograms divided by the square of the height in meters.¶The Roland disability questionnaire for sciatica is a disease-specific disability scale that measures functional status in patients with pain in the leg or back. Scores range from 0 to 23, with higher scores indicating worse functional status.‡The intensity of pain was indicated on a horizontal 100 mm visual analogue scale, with 0 representing no pain and 100 the worst pain ever experienced.∫Perceived recovery was defined as complete or nearly complete disappearance of symptoms according to the Likert-7 point scale.