Table 2 Baseline physical (self-reported) and MRI characteristics of participants

Pain and function

 RMDQ disability score (0–23) (609), mean (SD)

12.7 (5.7)

 Back pain intensity (609), mean (SD)

5.6 (2.2)

 Leg pain intensity (608), mean (SD)

5.2 (2.4)

 Pain below knee (584)

394 (67.5)

 Leg pain worse than back pain (609)

280 (46.0)

 Sleep disturbance due to back/leg pain^b(609)

428 (70.3)

First ever episode of back/leg pain (609)

58 (9.5)

Duration of symptoms

 Back pain current episode (607)

  Less than 6 weeks

218 (35.9)

  6–12 weeks

126 (20.8)

   >3 months

263 (43.3)

 Leg pain current episode (583)

  Less than 6 weeks

251 (43.1)

  6–12 weeks

120 (20.6)

   >3 months

212 (36.4)

Start Back prognostic risk score (589)

  Low Risk

82 (13.9)

  Medium Risk

276 (46.9)

  High Risk

231 (39.2)

Sciatica Bothersomeness Index (SBI),

mean (SD)

 Leg pain (583)

4.3 (1.5)

 Numbness or tingling in leg, foot or groin (583)

3.2 (2.1)

 Weakness in leg or foot (582)

2.6 (2.1)

 Back or leg pain while sitting

4.1 (1.6)

  Composite score (582)

14.2 (5.4)

 S-LANSS; neuropathic pain score (>12) (607)

293 (48.1)

Imaging(553)

 Positive MRI findings for nerve root compression

297 (53.7)