The clinical effectiveness and
cost-effectiveness of management
strategies for sciatica: systematic
review and economic model
R Lewis,1* N Williams,1 HE Matar,1 N Din,1
D Fitzsimmons,2 C Phillips,2 M Jones,1
A Sutton,3 K Burton,4 S Nafees,1 M Hendry,1
I Rickard,5 R Chakraverty6 and C Wilkinson1
1Department of Primary Care and Public Health, Cardiff University,
School of Medicine, North Wales Clinical School, Wrexham, UK
2School of Human and Health Sciences, Swansea University,
3Department of Health Sciences, University of Leicester, Leicester, UK
4Spinal Research Institute, University of Huddersfield,
5Patient representative, Betws-y-coed, UK
6The Spinal Unit, Royal Orthopaedic Hospital NHS Trust,
Health Technology Assessment 2011; Vol. 15: No. 39
Health Technology Assessment
NIHR HTA programme
Clinical effectiveness and cost-effectiveness of
management strategies for sciatica
iiExecutive summary: Clinical effectiveness and cost-effectiveness of management strategies for sciatica
Previous systematic reviews have found evidence for the clinical effectiveness of invasive
treatments such as epidural steroid injection, chemonucleolysis and lumbar discectomy in the
treatment of sciatica, but found insufficient evidence for less invasive treatments. None of the
reviews has made indirect comparisons across separate trials or has examined cost-effectiveness.
To determine the clinical effectiveness and cost-effectiveness of different management strategies
for sciatica by undertaking a systematic review and an economic evaluation.
Major electronic databases (for example MEDLINE, EMBASE and the NHS Economic
Evaluation Database) and several internet sites including trial registries were searched up to
December 2009. No language restrictions were used. Studies examining clinical effectiveness and
cost-effectiveness were reviewed separately. Any comparative study or full economic evaluation
was considered for inclusion. Studies involving adults who had sciatica or lumbar nerve root pain
diagnosed clinically or confirmed by imaging were eligible. The essential clinical criterion was leg
pain worse than back pain. Studies that included participants with lower back pain were included
only if the findings for patients with sciatica were reported separately. Any intervention or
comparator used to treat sciatica was included. Data were extracted by one reviewer and checked
by a second reviewer. Quality assessment was conducted independently by two reviewers.
Disagreements were resolved by discussion and, when necessary, a third reviewer was consulted.
For the review of clinical effectiveness, interventions were grouped into 18 treatment categories.
The analyses were limited to three patient-centred outcome domains – global effect (or overall
improvement), reduction in pain intensity (on a continuous scale of 0–100) and improvement in
condition-specific functional status – and any reported adverse effects. The data were analysed
according to three follow-up intervals: short (≤ 6 weeks), medium (> 6 weeks to 6 months)
and long term (> 6 months). The global effect was synthesised as binary data using odds ratios
(ORs) and pain intensity and a composite condition-specific outcome measure (CSOM) as
continuous data using weighted mean difference and standardised mean difference, respectively.
Missing study-level outcome data, where feasible, were dealt with by deriving/imputing
Mixed treatment comparison (MTC) meta-analyses were carried out to enable the simultaneous
comparison of all treatment modalities for sciatica at a single follow-up interval (closest to
6 months). The analyses were conducted for the three main outcome domains, for all study
designs and then after excluding observational studies and non-randomised trials.
The economic evaluation was based on a review of cost-effectiveness studies and a descriptive
decision-analytic model, based on estimates of global effect (from the MTC analysis) and cost
estimates derived from the literature following consultation with clinical experts.
iii Health Technology Assessment 2011; Vol. 15: No. 39 (Executive summary)
Results of review
The searches identified 33,590 references, of which 270 studies that met the inclusion criteria
were identified and 12 of these also included a full economic evaluation. A further 42 ongoing (or
not yet reported) studies and 93 publications that could not be translated were identified.
Review of clinical effectiveness
The number of studies evaluating invasive interventions such as surgery, epidural and
chemonucleolysis was greater than the number evaluating non-invasive interventions such
as education/advice, alternative therapies, manipulation and opioid medication. The number
of studies evaluating each treatment category ranged from two (manipulation and education/
advice) to 63 (disc surgery). The proportion of studies that were randomised control trials (RCTs)
also varied, with the lowest being for disc surgery (51%), anti-inflammatory biological agents
(50%) and chemonucleolysis (47%). The proportion that were deemed good quality ranged from
0% (chemonucleolysis, non-opioids, traction, alternative therapies, passive physical therapies,
biological agents and education/advice) to 50% (manipulation, 1 out of 2); 14% of epidural
studies and 3% of surgery studies were deemed to be good quality.
All but one study included patients with nerve root pain (or a combination of both nerve root
and referred pain). The presence of disc herniation was confirmed by imaging in a greater
proportion of studies evaluating invasive treatments than non-invasive interventions, as was
the proportion of studies that did not limit inclusion to patients with acute sciatica (duration of
symptoms being < 3 months), although this was not reported for many studies. Five treatment
categories included a small number of studies that limited inclusion to patients experiencing their
first episode (disc surgery, epidural injections, chemonucleolysis, non-opioid medication and
biological agents). The proportion of studies that included patients who had received previous
treatment were higher for invasive treatments compared with less invasive interventions, but the
proportion was also fairly high for opioids and activity restriction and low for biological agents.
Results from the standard pair-wise meta-analyses were in broad agreement with those from the
MTC analyses. The MTC provides an estimate of the relative treatment effects of the different
management strategies at a single follow-up interval (closest to 6 months). We found a high level
of between-study heterogeneity, so the results from the MTC analyses should be interpreted
Statistically significant findings were found for the following comparisons. Compared
with inactive control, disc surgery [odds ratio (OR) 2.8], epidural injections (OR 3.1),
chemonucleolysis (OR 2.0), non-opioids (OR 2.6) and alternative therapies (OR 4.7) resulted
in greater overall improvement; epidural injections [weighted mean difference (WMD) –12.9],
alternative therapies (WMD –26.1) and biological agents (WMD 21.8) resulted in better pain
relief; and biological agents (SMD –0.7) resulted in better back specific function. When compared
with usual care, disc surgery (OR 3.4), epidural injections (OR 3.8), chemonucleolysis (OR 2.4),
non-opioids (OR 3.1) and alternative therapies (OR 5.7) resulted in better overall improvement.
When compared with non-opioids, alternative therapies (WMD –22.1) and biological agents
(WMD –17.8) were better for pain relief; and biological agents were better for improving
functional status (standardised mean difference –0.8). When compared with opioids, epidural
injections (WMD –22.2), alternative therapies (WMD –35.5) and biological agents (WMD –31.2)
were better for pain relief; and when compared with activity restriction, alternative therapies
(WMD –44.1) and biological agents (WMD –39.7) were also better for reducing pain. Biological
agents were also better than passive physical therapy (PT) for pain relief (WMD –22.3).
ivExecutive summary: Clinical effectiveness and cost-effectiveness of management strategies for sciatica
Pair-wise meta-analyses were performed at short-, medium- and long-term follow-up and
the statistically significant improvements were found for the following treatment groups. Disc
surgery was superior to usual care (global effect, pain and CSOM at short-, medium- and long-
term follow-up) and epidural injection (pain short-term follow-up), non-opioids (pain and
CSOM at short-term follow-up), passive PT (global effect at medium- and long-term follow-up)
and activity restriction (global effect at medium-term follow-up). Chemonucleolysis was superior
to inactive control (pain at medium-term follow-up). Biological agents were superior to inactive
control and non-opioid medication (global effect and pain at short-term follow-up). Non-opioid
medication was superior to opioids (pain at short- and medium-term follow-up). Traction was
superior to activity restriction (pain at short-term follow-up). Passive PT was superior to inactive
therapy (pain at short-term follow-up). Spinal manipulation was superior to inactive control
(global effect at medium-term follow-up).
Pair-wise analyses of adverse effects found that there was a statistically significant greater number
of adverse effects in: disc surgery compared with usual care; epidural injection compared with
education/advice, passive PT or usual care; non-opioids compared with inactive control; traction
compared with activity restriction; manipulation compared with education/advice; and opioids
compared with inactive control.
Review of economic evaluations
The full economic evaluations identified in the systematic review were of reasonable to good
quality, but were not able to fully address our research question. Although individual studies
raised a number of important issues, it was difficult to draw meaningful conclusions across these
studies because of their heterogeneity. Although there was some indication of benefit, such as in
the case of disc surgery, robust findings could not be reliably drawn. Although an evidence base
is emerging, there remains a dearth of well-designed economic evaluations. In particular, there
is a lack of published decision models. Furthermore, the relevance to the UK NHS setting of the
studies that have been published is unclear.
A decision-analytic model from the perspective of the UK NHS was constructed on the
assumption that patients presenting with sciatica would be managed through one of three
pathways, with alternative treatments within each of the pathways. The first pathway would
involve management within primary care and revolve around what might be termed usual care,
with the use of analgesics and other medications if considered appropriate, to attempt to secure
symptom resolution. The second pathway would involve a stepped-care approach and include
the use of intermediate treatments – offered in addition to the initial treatments provided
within primary care – and provided in secondary care outpatients by multidisciplinary teams
including physiotherapists, musculoskeletal physicians, etc.; the principle is one of ramping
up the level of intervention if there is no timely symptom resolution following simpler, less
invasive interventions. The third pathway would involve immediate referral for surgery to
Each of the pathways and the treatment variations available were compared with ‘inactive
control’ which, according to the findings from the MTC, has a non-zero probability of symptom
resolution, but has been assumed to cost £0 in the baseline model.
v Health Technology Assessment 2011; Vol. 15: No. 39 (Executive summary)
A series of 100 independent scenarios were considered, with the utilities associated with success
used to generate a utility score for each treatment regime and combined with costs to determine
relative incremental cost-effectiveness ratios and a series of sensitivity analyses were conducted
on the baseline findings.
Results of economic evaluation
The treatment regimes that were shown to be the most cost-effective were inactive control;
non-opioids followed by alternative/non-traditional treatments; non-opioids followed by
alternative/non-traditional treatments followed by epidural; non-opioids followed by alternative/
non-traditional treatments followed by epidural followed by disc surgery; and non-opioids
followed by biological therapies followed by epidural and followed by disc surgery. Although,
this last regime would not be regarded as cost-effective when measured in terms of current cost-
effectiveness thresholds employed at national level in the UK NHS.
These findings provide support for the effectiveness of currently used therapies for sciatica,
such as non-opioid medication, epidural corticosteroid injections and disc surgery, but also for
chemonucleolysis, which is no longer used in the UK NHS. In addition, these findings do not
provide support for the clinical effectiveness of opioid analgesia, which is widely used in this
patient group. They also suggest that less frequently used treatments, such as acupuncture, and
experimental treatments, such as anti-inflammatory biological agents, may be effective.
In terms of cost-effectiveness, the argument for stepped approaches based on an initial treatment
with non-opioids, as opposed to direct referral for surgery, was apparent, although there are a
number of limitations associated with the economic model.
Further research is needed to evaluate the use of biological agents and acupuncture compared
with interventions that are currently being used such as non-opioids and epidural injections.
Further research is also needed to compare the use of opioids with drugs used to treat neurogenic
nerve pain or other treatments currently in use.
Recommendations for future research
The following areas are recommended for further investigation:
RCTs with concurrent economic evaluation of biological agents compared either with
placebo or with currently used treatments
RCTs with concurrent economic evaluation of acupuncture compared with other currently
RCTs with concurrent economic evaluation of opioids compared with drugs used to treat
neurogenic nerve pain, such as tricyclic antidepressants and gabapentin (Neurontin, Pfizer)
development of alternative economic modelling approaches to assess relative cost-
effectiveness of treatment regimes, based on the above trial data.
viExecutive summary: Clinical effectiveness and cost-effectiveness of management strategies for sciatica
Funding for this study was provided by the Health Technology Assessment programme of the
National Institute for Health Research.
Lewis R, Wiliams N, Matar HE, Din N, Fitzsimmons D, Philips C, et al. The clinical effectiveness
and cost-effectiveness of management strategies for sciatica: systematic review and economic
model. Health Technol Assess 2011;15(39).
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