Robb, K.A., Bennett, M.I., Johnson, M.I., Simpson, K.J., & Oxberry, S.G. (2008). Transcutaneous electric nerve stimulation (TENS) for cancer pain in adults. Cochrane Database of Systematic Reviews, 3, CD006276.
To determine the effectiveness of transcutaneous electric nerve stimulation (TENS) in management of cancer-related pain and to provide guidance for optimal parameters of TENS for pain relief
Databases searched were The Cochrane Library, MEDLINE, Embase, CINAHL, AMED, PEDro, and PsycINFO. Hand-searching of reference lists of articles retrieved was also done.
MeSH terms were Neoplasms [*complications]; Pain [etiology;*therapy] Randomized controlled trials as Topic; Transcutaneous Electric Nerve Stimulation (TENS) [*methods] Adults; Humans. An extensive listing of search strategies and terms for each database used are provided.
Studies were included in the review if they
Studies were excluded if they
The search identified 36 studies from 1975 to 2008, and reference lists identified an additional 7 studies. Only two studies met all inclusion criteria. Study quality was assessed using the Oxford Quality Scale (Jadad scale).
The majority of studies initially retrieved from the search were eliminated due to design that was either not an RCT or where clinical results were not reported. No meta-analysis could be done due to the small sample size with final studies included. In one study, TENS was compared to sham TENS in women. The only outcome measure with significant differences between groups was one dimension of a patient satisfaction questionnaire. In the other study, there were no significant differences between groups.
No conclusions regarding the effectiveness of TENS could be made due to the lack of studies that met criteria.
This review was limited by the inclusion criteria that TENS had to be compared to no treatment. The ethics of having such a control or placebo group in patients with chronic pain and in end-of-life care is questionable, and the inability to find enough studies that met this strict criteria is not surprising. Results were inconclusive due to lack of suitable RCTs.
There is little data to demonstrate effectiveness of TENS for cancer-related pain. In patients with chronic pain, the insistence upon a placebo control group in an RCT is not reasonable and appropriate, and such limitations will not serve to advance knowledge in this area. Additional research with adequate sample sizes is needed in this area.