Transcutaneous electrical nerve stimulation for primary dysmenorrhoea: Cochrane systematic review
Assessed as up to date: 2009/05/02
Medical therapy for dysmenorrhoea (painful menstrual cramps of the uterus) such as non-steroidal anti-inflammatory drugs or the oral contraceptive pill work by reducing myometrial (uterine muscle) activity. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological intervention shown to be effective for pain relief in a variety of conditions. TENS may be able to alter the body's ability to receive and perceive pain signals rather than having a direct effect on uterine contractions.Objectives
To determine the effectiveness of high and low-frequency TENS when compared to placebo, no treatment, or medical treatment for primary dysmenorrhoea.Search strategy
Electronic searches of the Cochrane Menstrual Disorders and Subfertility Group Register of controlled trials, The Cochrane Library (Issue 1, 2009), MEDLINE, EMBASE, CINAHL, and AMED were performed (updated April 2009) to identify relevant randomised controlled trials. The Cochrane Complementary Medicine Field Register of controlled trials (CISCOM) was also searched. Attempts were also made to identify trials from the UK National Research Register, the Clinical Trial Register, and the citation lists of review articles and included trials.Selection criteria
The inclusion criteria were: randomised controlled trials (RCTs) of TENS compared to placebo, no treatment, or medical treatment for primary dysmenorrhoea. Exclusion criteria were: mild, infrequent, or secondary dysmenorrhoea and dysmenorrhoea associated with an intrauterine device (IUD).Data collection and analysis
Seven RCTs were identified that fulfilled the inclusion criteria for this review. No new studies were identified in the update. Quality assessment and data extraction were performed independently by two review authors. Data unsuitable for meta-analysis were reported as descriptive data and were included for discussion. The outcome measures were pain relief (dichotomous, visual analogue scale, descriptive), adverse effects, use of analgesics additional to treatment, and absence from work or school.Main results
Overall, high-frequency TENS was shown to be more effective for pain relief than placebo TENS (OR 7.2, 95% CI 3.1 to 16.5). Low-frequency TENS was found to be no more effective in reducing pain than placebo TENS (OR 1.48, 95% CI 0.43 to 5.08). There were conflicting results regarding whether high-frequency TENS was more effective than low-frequency TENS.Authors' conclusions
High-frequency TENS was found to be effective for the treatment of dysmenorrhoea by a number of small trials. The minor adverse effects reported in one trial require further investigation. There is insufficient evidence to determine the effectiveness of low-frequency TENS in reducing dysmenorrhoea.
Proctor Michelle, Farquhar Cindy, Stones Will, He Lin, Zhu Xiaoshu, Brown Julie
Transcutaneous electrical nerve stimulation for primary dysmenorrhoea
High-frequency nerve stimulation may help relieve painful menstrual cramps. Dysmenorrhoea is a very common complaint that refers to painful menstrual cramps in the uterus. Transcutaneous electrical nerve stimulation (TENS) involves the sending of an electric current by placing electrodes on the skin to stimulate the nerves and reduce pain. It is thought to alter the body's ability to receive and understand pain signals rather than by having a direct effect on the uterine contractions. The review of trials found that high-frequency TENS may help but there is not enough evidence to assess the effect of low-frequency TENS. More research is needed.
Implications for practice
The available data on high-frequency TENS suggest it is effective for the treatment of dysmenorrhoea. The clinical importance of the minor adverse effects that were reported in one study is unclear. TENS represents a suitable alternative for women who prefer not to use medication or wish to minimise their NSAID consumption. There are some data to suggest that women using TENS are less likely to require additional analgesia, an observation that supports clinical advice to consider TENS as an option, although the degree of relief obtainable from TENS alone is less than that from analgesic drugs.
The present review has not demonstrated the efficacy of low-frequency TENS. This may be because the single study was insufficiently powered. Clear recommendations for practice cannot be made.
Implications for research
It is likely that women experiencing dysmenorrhoea will continue to seek advice on and treatment with TENS, therefore further research is needed to establish the optimal manner in which TENS modalities should be used. The condition is very common and the lifestyle impact and economic burden justifies a search for effective and acceptable treatments. Inclusion of cost comparisons and outcomes in clinical trials will enable better assessment of the true value of treatment interventions. There is a need to improve the quality of future randomised controlled trials. The methods of trials need to be fully described so as to aid the reader as to the validity and relevance of reported studies. In particular, allocation blinding needs to be meticulous within the practical constraints discussed above.
Methodologically sound and adequately powered clinical trials are needed evaluating the role of low-frequency TENS for primary dysmenorrhoea. More information is needed on the potential adverse effects of high-frequency TENS and the acceptability of TENS treatments to women needs to be explored using both questionnaires and qualitative methods.Get full text at The Cochrane Library
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