What evidence is available in the literature with regard to stimulation of peripheral nerves for treating refractory pain?

What techniques have been used, and for what types of refractory pain?

What is the best available evidence concerning the efficacy and safety of each of the techniques for each type of refractory pain?

The following sources will be searched:

• The Cochrane Library (Wiley), including the Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA) database

• The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), MEDLINE In Process (Ovid), EMBASE (Ovid), and CINAHL (EBSCO)

• The ZETOC (Mimas) database and Conference Proceedings Citation Index (ISI Web of Knowledge) for conference proceedings

• Current Controlled Trials metaRegister, NIHR Clinical Research Network Portfolio and ClinicalTrials.gov for ongoing studies.

Searches will be restricted to human studies. No restriction on language or publication period will be applied.

The selection of studies for inclusion will be a two-stage process. The first stage aims to identify all literature that is relevant to the intervention (peripheral nerve stimulation) and population (patients with chronic refractory pain) under consideration; the second stage aims to select evidence that is most relevant (of highest internal validity and/or clinical relevance) for more detailed assessment.

Stage 1:

Inclusion criteria: any study design that systematically synthesises or assesses patient outcomes, including systematic reviews, RCTs, non-randomised controlled studies, uncontrolled before-and-after studies, case series and case reports.

Exclusion criteria: narrative reviews, commentaries, editorials and letters (unless including case reports or new data); economic evaluations and cost studies; in-vitro studies; animal studies.

Records that are selected during Stage 1 will be mapped to a matrix showing different possible combinations of peripheral nerve stimulation techniques and types of pain. The framework for the matrix will be developed with advice from clinical and technical experts and the matrix will be constantly updated throughout the review process.

Stage 2:

Based on the above matrix, studies that present the best available evidence for each pair of technique-pain type will be selected for detailed assessment. The selection will be made by consensus from discussions between review team members (and clinical experts where necessary), and consideration will be given to the following factors highlighted in NICE’s Methods Guidance for the Interventional Procedures Programme (NICE 2007):

• Study design

• Sample size

• Follow-up length and completeness

• Patient-focused outcomes

• Language and publication type (non-English language articles and conference abstracts will be selected for detailed review only if they are thought to add substantively to the evidence base)

This review focuses on refractory pain, which refers to chronic pain (persisting for 3 months or longer) that does not respond to standard treatments. There are several types of chronic pain, classified using different criteria, such as aetiology. Nociceptive pain is associated with damage to tissues such as muscle, skin and bones, whereas neuropathic pain is caused by primary lesions or dysfunction in the nervous system. Chronic pain can sometimes be related to both nerves and tissue damage, or have unknown origin. This review aims to cover all refractory pain. Classification of pain is based upon the Classification of Chronic Pain by the International Association for the Study of Pain (IASP 1994 and its subsequent revisions) and the International Classification of Headache Disorders (2nd edition) by the International Headache Society.

Inclusion criterion: patients with chronic pain.

Exclusion criteria: patients with acute pain; mixed population of acute and chronic pain where results could not be disaggregated.

Inclusion criterion: any invasive techniques of stimulation of peripheral nerves.

Exclusion criteria: non-invasive techniques of electrical stimulation (e.g. transcutaneous electrical nerve stimulation [TENS]); stimulation of brain or spinal cord; electroacupuncture.

Any comparator/control will be considered, including placebo/sham control. Studies without a control group (e.g. case series) will also be considered initially.

This systematic review is commissioned by NICE in order to support the development of NICE Interventional Procedures guidance. The scope of this review and its methodology has been developed within this context.

Primary outcomes

• Pain relief (immediate and long-term) and time to pain relief; pain recurrence rates and time to pain recurrence; pain self efficacy; analgesic use.

• Adverse effects, complications, technical failures, complications of procedure.

• Quality of life.

Secondary outcomes

Other relevant measures of efficacy will be noted but not reviewed in detail: depression, anxiety, sleep outcome, patient and clinician impression of change and satisfaction of treatment.

Data will be abstracted from primary studies that are selected during the Stage 2 of the study selection process on to a structured evidence table, which contains the following items (modified from NICE IP Programme methods guide) and the aforementioned items for quality assessment:

• Citation information

• Study design

• Country (or countries) where study was conducted

• Study period

• Study sample size (total number of patients and, when relevant, number of patients treated with the procedure of interest)

• Eligibility criteria for entering the study

• Population characteristics (age, sex and other relevant demographic data)

• Types of pain and duration of symptoms

• Technique (details of nerve stimulation procedure performed) and comparator (where relevant; details of any placebo or sham procedure performed)

• Follow-up period (mean or median where stated)

• Baseline and post-intervention measurements of pain and quality of life; adverse events including complications of the procedures

• Details of any conflict of interest declared by the authors of the report.

The items will be modified as appropriate for abstracting data from published systematic reviews. Data extraction and quality assessment will be carried out by one reviewer and checked by another reviewer. Disagreements will be resolved by discussion or seeking advice from a third reviewer.

Studies that are selected during the Stage 2 of study selection process will be assessed for methodological quality. Quality assessment will be carried out using established checklists pertinent to the design of individual studies (Shea et al. 2007, Higgins and Green 2011), including cross-over trials (Mills et al. 2009) and case series (Dalziel et al. 2005, Chambers et al. 2009) that are commonly seen in this field of literature. One particular challenge for the review will be assessment of outcomes related to pain. We will consult published guidelines related to the conduct and evaluation of trials related to pain and migraine by the Cochrane Back Review Group and the International Headache Society.

Cited references:

Chambers D, Rodgers M, Woolacott N (2009) Not only randomized controlled trials, but also case series should be considered in systematic reviews of rapidly developing technologies. Journal of Clinical Epidemiology;62:1253-60.

Dalziel K, Round A, Stein K, Garside R, Castelnuovo E, Payne L (2005) Do the findings of case series studies vary significantly according to methodological characteristics? Heatlh Technol Assess;9(2).

Higgins JPT, Green S [editors] (2011). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration. Available from www.cochrane-handbook.org.

Mills EJ, Chan A-W, Wu P, Vail A, Guyatt GH, Altman DG (2009) Design, analysis, and presentation of crossover trials. Trials;10:27.

Shea BJ, Grimshaw JM, Wells GA et al. (2007) Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology;7:10.

The aforementioned matrix will be used to create a map of evidence for the techniques of peripheral nerve stimulation and types of pain covered in this review. The evidence map will guide the structure of the report and provide an overview of quality and quantity of evidence for each technique and type of pain.

Evidence will be presented by major techniques of peripheral nerve stimulation, with subsections describing their application for each type of pain. Depending on the number of studies selected for detailed assessment within each technique-pain combination, ad hoc tables summarising evidence from multiple studies or evidence tables for individual studies will be presented. Safety evidence for a particular stimulation technique may be summarised across different types of pain where appropriate. Standard meta-analytical methods will be used where the quantity and quality of data permits; however it is envisaged that there will be insufficient data for quantitative synthesis for most technique-pain combinations.

As stated above, analysis (either narrative or quantitative) will be carried out by main types of techniques and also by types of pain.

It is expected that the systematic review will be made available as a report on the NICE website as a supporting document for the NICE Interventional Procedures guidance to be issued. We will also write up the systematic review as article(s) for peer-reviewed journal(s).

Yen-Fu Chen

90 Vincent Drive

School of Health & Population Sciences

University of Birmingham

Edgbaston

Birmingham B15 2TT

United Kingdom

y.chen.3@bham.ac.uk

University of Birmingham

http://www.birmingham.ac.uk/schools/haps/index.aspx

Dr Yen-Fu Chen, University of Birmingham
Mr George Bramley, University of Birmingham
Ms Janine Dretzke, University of Birmingham
Dr David Moore, University of Birmingham
Ms Sue Bayliss, University of Birmingham
Dr Dalvina Hanu-Cernat, University Hosptials Birmingham NHS Foundation Trust
Dr Steve Sturman, City Hospital, Birmingham
Dr Carole Cummins, University of Birmingham
Professor Richard Lilford, University of Birmingham

02 March 2012

01 November 2012

National Institute for Health and Clinical Excellence (NICE), UK

RX-006-IP-969

None known

English

England

Subject indexing assigned by CRD

Electric Stimulation Therapy; Humans; Pain, Intractable; Peripheral Nerves

Whilst we will attempt to cover main techniques of peripheral nerve stimulation and types of chronic pain as comprehensive as possible during the literature search and evidence mapping parts of the systematic review (Stage 1), detailed assessment of evidence (Stage 2 of the review) will necessarily focus on a few selected areas where the evidence is currently of sufficient quality/quantity. We therefore encourage researchers who are considering to undertake a systematic review of specific technique(s) of peripheral nerve stimulation for specific type(s) of pain in the near future to contact us regarding the final areas that we will focus on for detailed assessment. They need not be deterred from planning a new review within this broad area.

23 July 2012

23 July 2012