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Table 3 Individual Study Characteristics

From: Prognostic factors in non-surgically treated sciatica: A systematic review

ID Author Population studied Subjects Sciatica definition Treatment Follow-up (months) Study Quality Predictors studied Outcomes measured
1 Balague et al (1999)
Consecutive hospital admissions with severe acute sciatica 82
66% male
mean age 43 yrs
73 at follow-up
Unilateral leg pain +/- LBP
positive neurological signs
radiological evidence of spinal nerve root compression
Conservative "intensive pain management" 12 High Age, gender, duration of symptoms, smoking, previous sciatica, EMG, BMI, QOL, disability, pain, imaging results (MRI, CT), neurological signs, antibody test "Recovery" (composite score including pain, disability & muscle strength)
Recovery defined as:
ODI Score ≤ 20
VAS pain ≤ 15
Normal muscle strength test (score 5)
2 Beauvais et al (2003)
Consecutive patients attending rheumatology departments with symptoms of sciatica or femoral neuralgia of < 1 month duration and disc herniation on CT 75
58% male
mean age 41 yrs
60 at follow-up
Symptoms & examination consistent with sciatic or femoral neuralgia
CT evidence of intervertebral disk herniation
Bed rest, analgesics, lumbar brace +/- epidural steroid injection
3 Adequate Age, gender, distribution of pain, duration of pain, previous sciatica, presence of severe pain requiring inpatient treatment, CT findings "Recovery"
Complete = return to usual work/activities, little or no analgesia
Partial = residual pain, frequent analgesic use, complete or partial return to work, limited athletic activities
Failure = persistent pain, continuous analgesic use, unable to return to work
3 Carragee & Kim (1997)
Consecutive patients referred to hospital for MRI scan with symptoms suggestive of sciatica and available for 2 year follow-up 188
58% male
mean age 42.5 yrs
135 at follow-up
Lower extremity radicular pain (greater than back pain)
Positive SLR test
or motor weakness
abnormal MRI scan
Usual care
Conservative 64% and surgical 36%
24 Adequate Disc morphology on MRI, age, gender, height, weight, duration, affected side, previous spinal surgery, occupation (heaviness of work), SLR, motor weakness, co-morbidity, smoking, alcohol, workers compensation, litigation, mode of treatment. Composite measure of overall outcome comprising sum of scores on 0-10 scale for self-reported pain, medication use, activity restriction and satisfaction, total divided by 4 to give outcome score
> 6 = good
≤6 = poor
4 Hasenbring et al (1994)
Consecutive patients admitted to hospital with acute radicular pain and radiologically diagnosed disc prolapse 111
60% male
mean age 41.7 yrs
90 at follow-up
Acute radicular
radiologically diagnosed lumbar disc prolapse or protrusion
Usual care
Surgical 66%
Conservative 34%
6 Adequate Depression (BDI), "daily hassles in fifteen areas of daily living including work, home, relationships and financial" (KISS)
"emotional, cognitive & coping reactions to pain" (KSI), health locus of control", duration of symptoms, nature of onset, previous surgery, disc displacement on imaging, paresis, scoliosis, treatment (surgical/conservative), obesity, age, social status, occupation (posture, heaviness of work), duration of inability to work
Pain Intensity
Self report
8 point scale
5 Jensen et al 2007
Consecutive patients referred to a specialist outpatient back pain centre with symptoms suggestive of sciatica and enrolled in an RCT of active conservative treatment 187
55.5% male
mean age 45 yrs
154 at follow-up
Radicular symptoms with a dermatomal distribution Conservative
Education, reassurance, analgesia, +/- exercise programme +/- manual physiotherapy
If surgery required patients excluded from follow-up analysis
14 High MRI findings (disc contour, height, signal & herniation); nerve root compromise; spinal stenosis (central, lateral, foraminal).
"Recovery" (composite score including pain on 11 point VRS & disability on RMDQ)
Recovery defined as:
Pain score < 1 & RMDQ ≤ 3
6 Komori et al 2002
Consecutive patients presenting to hospital with unilateral leg pain and with radiologically confirmed herniated disc 131
no demographic data presented
90 at follow-up
Unilateral leg pain
MRI evidence of herniated
nucleus pulposus
Usual care
Conservative - rest, medication, traction.
If surgery required patients excluded from follow-up analysis
12 Poor Age, gender, occupation (heaviness of work), previous LBP or sciatica, Duration of symptoms
Leg symptoms ( pain, SLR, FST, motor paresis & sensory disturbance)
Level & type of herniation/disc degeneration on MRI scan
Outcome defined according to residual self-reported symptoms and disability on 3 point scale (poor, fair, good)
7 Miranda et al (2002)
Employees of Finnish forestry industry receiving annual questionnaire about musculoskeletal pain 3312
74% male
mean age 45.3 yrs
2984 at follow-up
Self-reported low back pain with leg pain radiating below the knee None 12 High Age, gender, weight, height, smoking, driving, mental stress
Occupational activities (twisting, bending, kneeling or squatting, working with arms raised, lifting), heaviness of work, 'overload' at work, risk of accident at work,
Physical exercise and sporting activity in general & specific sports
Outcome defined as persistence of pain based on self report of sciatic pain
Persistence = sciatica pain on >30 days/year in 2 consecutive years (1994 & 1995) on modified NMQ)
8 Vroomen et al (2002)
Consecutive patients presenting to GP with 1st episode of sciatica and pain sufficient to justify further therapy. Study performed concurrently with RCT of bed rest 183
56% male
mean age 46 yrs
169 at follow-up
Leg pain in dermatomal distribution
≥ 2 of the following:
• Increased pain on coughing & sneezing
• Sensory loss
• Muscle weakness
• Reflex loss
• Positive nerve root irritation signs
Usual care
Surgery if indicated (15%)
A second analysis excluding patients who had surgical treatment (n = 156) was performed
3 Adequate Age, gender, education, living alone, employment, previous sciatica, previous LBP, family history, co-morbidity, smoking, sporting activity, BMI, Duration of symptoms, revised Oswestry score, Roland disability score, MPQ score
Leg pain > back pain
Pain-related symptoms and examination findings (SLR, FST, paresis, sensory loss, finger to floor distance)
Poor outcome defined as absence of any improvement at 3 months based on self-reported change in symptoms
  1. BDI Beck Depression Inventory
  2. BMI Body Mass Index
  3. CT Computed Tomography
  4. EMG Electromyogram
  5. FST Femoral Stretch test
  6. KISS Kiel Inventory of Subjective Situations
  7. KSI Kiel Pain Inventory
  8. LBP Low back pain
  9. MPQ McGill Pain Questionnaire
  10. MRI Magnetic Resonance Imaging
  11. NMQ Nordic Questionnaire
  12. ODI Oswestry Disability Index
  13. QOL Quality of life
  14. RMDQ Roland Morris Disability Questionnaire
  15. SLR Straight leg raise test
  16. VAS Visual Analogue Score
  17. VRS Verbal Rating Scale