Authors' objectives:

TENS is a non-invasive therapeutic option, generally used to relieve pain, which uses peripheral nerve electrical stimulation by means of electrodes placed on the skin surface at known well-tolerated intensities. PENS, on the other hand, uses needle-like electrodes, similar to those used in acupuncture which are 1-4 cm long, located in soft tissues or muscles at the corresponding dermatomes for that local pathology. Its usefulness has been proposed in several applications, among which is the relief of post-surgical and skeletal muscle pain, as well as pain from other causes.

Authors' results and conclusions: A systematic Cochrane review of 2000 which examined the efficacy of TENS for the treatment of chronic low back pain did not find significant differences in results as regards pain [the summary odds ratio for pain improvement in the comparisons was 1.52 for TENS versus placebo CI 95% 0.90-2.58]. In a more recent systematic review two randomized studies were included, totalling 175 patients. Both studies showed conflicting results between them. According to this version, the evidence of TENS efficacy as single intervention for chronic low back pain management is limited and inconsistent. In a systematic review, Carroll et al identified 46 reports using TENS for acute post-operative pain. They concluded that there were no definite advantages for TENS when compared to other alternatives. Milne et al carried out a systematic review on the efficacy of TENS for chronic low back pain in 2001. They included five RCTs with 170 subjects randomly assigned to the placebo group, who received sham TENS and 251 who received active TENS (153 using the conventional mode and 98 acupuncture type). There were no statistically significant differences between the group of active TENS compared with the placebo group for any of the results. In 2001, the US Department of Veteran Affairs pointed out that the medical literature at the moment the revision was made was not conclusive regarding the effectiveness of TENS effectiveness in pain management. It states that the quality of the evidence is, in general, insufficient, and results are equivocal compared with other therapeutic alternatives. In 1995, the Canadian Agency for Drugs and Technology in Health (CADTH) assessed the clinical value of TENS for pain management and concluded that there was little evidence of its efficacy. PENS effectiveness One RCT with a crossover design including 68 patients presenting chronic low back pain treated at different frequencies was identified. Stimulation at 15-30 Hz was found to be better than 4-100 Hz when compared with sham PENS in the results assessed with two-week follow-up. No tests of statistical significance were provided. Weiner et al randomized 34 65-year-old adults who presented chronic low back pain to receive PENS twice weekly plus exercise, versus sham PENS plus exercise for 6 weeks. Subjects reported an improvement in pain intensity measurements, as compared with pre-treatment measurements, which remained at three months.

Authors' recommendations: The decision as to include or exclude TENS as treatment for chronic low back pain is poorly supported by evidence. It has not categorically been demonstrated that the effects of TENS exceed those of placebo. It is not known whether its effectiveness changes with the different types or application areas, duration of treatment, frequencies or intensities. Reports do not provide information on long term effectiveness. New and larger randomized trials of better methodological quality, using standardized measurement of results are still required.

Authors' methods: Overview

Project Status: Completed

URL for project: http://www.iecs.org.ar/

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Argentina

Organisation Name: Institute for Clinical Effectiveness and Health Policy

Contact Address: Dr. Emilio Ravignani 2024, Buenos Aires - Argentina, C1414 CABA

Contact Name: info@iecs.org.ar

Contact Email: info@iecs.org.ar

Copyright: Institute for Clinical Effectiveness and Health Policy (IECS)