Table 3 Study characteristics

Divecha et al., 2014

United Kingdom

n = 89

Age:

25–79, mean 48.6

Gender:

Male n = 46 [51.7%] Female n = 43 [48.3%]

1 year

n = 32 [35%]

• Pre-operative leg pain [% of pain that was radicular, calculated from the Core Outcome Measures Index [COMI]

• COMI score – patient completed assessment through Spine Tango. Includes questions on the severity of leg and back pain.

• Definition of outcome unclear for multivariate analyses

Fisher et al., 2004

Canada

n = 82

Age:

17–83, mean 42.2

Gender:

Male n = 52 [63.4%] Female n = 30 [36.6%]

1 year

n = 71 [87%]

• Pre-operative duration of leg pain in months

• Health Related Quality Of Life [HRQOL] outcome comprising:

a. North American Spine Society instruments: Neurogenic Symptom Score and Pain/Disability Score

b. Short Form-36 [SF-36] questionnaire

Lewis et al., 1987

(and Weir, 1979)

Canada

n = 100

Age^a:

Mean [SD] 41.7 [1]

Gender:

Male 75%

Female 25%

1 year

N = 91 [91%]

5–10 years

n = 81 [81%]

• Pre-operative duration of leg pain in months

• Ipsilateral straight leg raise (detail of measurement not reported)

• Forward bend (detail of measurement tool not reported)

• Relief of back pain

• Relief of leg pain

• No multivariate analyses

Nygaard et al., 2000

Norway

n = 132

Age^a:

> 18

Gender:

Not reported

1 year

n = 132 [100%]

• Pre-operative duration of leg pain in months

• Pre-operative duration of back pain in months

• Clinical Overall Score, calculated from 40% weighting pain, 20% clinical examination, 20% functional status [Oswestry Disability Index, ODI] and 20% analgesia

Silverplats et al., 2010

Sweden

n = 171

Age^a:

Mean[SD] 39 [11]

Gender:

Male n = 95 [55.6%] Female n = 76 [44.4%]

2 years

n = 154 [90%]

Mean[SD] long term 7.3 [1.0] years

Range 5.1–9.3 years

n = 140 [81%]

• Pre-operative leg pain - recorded with three 0–100 Visual Analogue Scale [VAS] representing ‘pain when as worst’, ‘pain when as least’ and ‘pain right now’. Mean value of the three scales recorded

• Pre-operative back pain - recorded with three 0–100 VAS representing ‘pain when as worst’, ‘pain when as least’ and ‘pain right now’. Mean value of the three scales recorded

• Pre-operative duration of leg pain in months

• Pre-operative ODI- self complete questionnaire 0–100

Primary outcomes:

• MacNab classification of post-operative outcome [at 2 years] with 4 categories of outcome – excellent, good, fair, poor but unclear how applied as dichotomized outcome in multivariate analyses

• Satisfaction with treatment [satisfied, partly, not satisfied, both follow up points]

Secondary outcomes:

• Change in leg pain [improved, no improvement, worse]

• Change in back pain [improved, no improvement, worse]

Silverplats et al., 2011

Sweden

n = 117

Age:

18–66, mean 39

Gender:

Male n = 63 [54%]

Female n = 54 [46%]

Range 5–8 years

2 years 82%

7 years 76%

• Pre-operative duration of leg pain in months

• Pre-operative leg pain [detail of measurement not reported]

• Pre-operative back pain [detail of measurement not reported]

• Pre-operative EuroQol-5 Dimension [EQ-5D] score for HRQOL self-completion questionnaire 0–100

• Change in EQ- 5D score

Solberg et al., 2005

Norway

n = 228

Age:

Mean[SD] 41 [11]

Gender:

Male n = 114 [63.3%] Female n = 66 [36.7%]

1 year

n = 180 [78.9%]

• Pre-operative ODI score - self complete questionnaire 0–100

• Pre-operative duration of leg pain in months

• Pre-operative duration of back pain in months

• Pre-operative leg pain 0–100 VAS no pain to worst conceivable pain

• Pre-operative back pain 0–100 VAS no pain to worst conceivable pain

Primary outcome:

• ODI score classified as:

a. deterioration [increased ODI] or no deterioration [decreased/unchanged ODI]

b. poor [ODI > 39] or good [ODI < 40]

Secondary outcomes:

• VAS back pain

• VAS leg pain