Transcutaneous electrical nerve stimulation (TENS) for chronic pain

 

Abstract

Background

Transcutaneous electrical nerve stimulation (TENS) is a popular pain treatment modality but its effectiveness in chronic pain management is unknown. This review is an update of the original Cochrane review published in Issue 3, 2001.

Objectives

To evaluate the effectiveness of TENS in chronic pain.

Search methods

The Cochrane Library, EMBASE, MEDLINE and CINAHL were searched. Reference lists from retrieved reports and reviews were examined. Date of the most recent search: April 2008.

Selection criteria

RCTs were eligible if they compared active TENS versus sham TENS controls; active TENS versus 'no treatment' controls; or active TENS versus active TENS controls (e.g. High Frequency TENS (HFTENS) versus Low Frequency TENS (LFTENS)). Studies of chronic pain for three months or more which included subjective outcome measures for pain intensity or relief were eligible for evaluation. No restrictions were made to language or sample size. Abstracts, letters, or unpublished studies, and studies of TENS in angina, headache, migraine, dysmenorrhoea and cancer-related pain were excluded.

Data collection and analysis

Data were extracted and summarised on the following items: patients and details of pain condition, treatments, study duration, design, methods, subjective pain outcome measures, methodological quality, results for pain outcome measures and adverse effects, and conclusions by authors of the studies. Extracted data and methodological quality of studies were confirmed by the review authors.

Main results

Of 124 studies identified from the searches, 99 did not fulfil pre-defined entry criteria. Twenty-five RCTs involving 1281 participants were evaluated. Included studies varied in design, analgesic outcomes, chronic pain conditions, TENS treatments and methodological quality. The reporting of methods and results for analgesic outcomes were inconsistent across studies and generally poor. Meta-analysis was not possible. Overall in 13 of 22 inactive control studies, there was a positive analgesic outcome in favour of active TENS treatments. For multiple dose treatment comparison studies, eight of fifteen were considered to be in favour of the active TENS treatments. Seven of the nine active controlled studies found no difference in analgesic efficacy between High Frequency (HF) TENS and Low Frequency (LF) TENS.

Authors' conclusions

Since the last version of this review, new relevant studies have not provided additional information to change the conclusions. Published literature on the subject lacks the methodological rigour or robust reporting needed to make confident assessments of the role of TENS in chronic pain management. Large multi-centre RCTs of TENS in chronic pain are still needed.

 

Plain language summary

Effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) alone in the management of chronic pain

Despite the widespread use of TENS machines, the analgesic effectiveness of TENS still remains uncertain. This has mainly been due to inadequate methodology and reporting in earlier studies but more recent studies of TENS for chronic pain fail to offer necessary improvements in methodological rigour to define the place of TENS in chronic pain management with any certitude. The search process identified 124 studies; 25 met the inclusion criteria for evaluation in this review but there were insufficient extractable data to make meta-analysis possible. New studies of rigorous design and adequate size are needed before any evidence-based recommendations can be made for patients or health professionals.

 

摘要

背景

經皮穿刺神經電刺激(Transcutaneous electrical nerve stimulation ；TENS)治療慢性疼痛

經皮穿刺神經電刺激(TENS)治療在各種不同狀況的急性和慢性疼痛，已深受病人和衛生專業人員的喜愛，但是在慢性疼痛管理的效益卻仍不清楚。本回顧為2001年第3季發表的Cochrane文獻回顧的更新版本。

目標

評量經皮穿刺神經電刺激治療慢性疼痛的療效。

搜尋策略

我們搜尋了The Cochrane Library、 Embase和CINAHL and The Oxford Pain Database等資料庫。參考清單是由檢選的報告和評論中選出來。最近期檢索的日期是2008年4月。

選擇標準

如果包含以下治療的比較，就是符合本評論的隨機對照試驗：*執行經皮穿刺神經電刺激治療 和偽經皮穿刺神經電刺激(sham TENS) 當控制組的比較。*執行經皮穿刺神經電刺激治療和無治療的控制組的比較。*執行經皮穿刺神經高頻電刺激(High Frequency TENS；HFTENS)治療和經皮穿刺神經低頻電刺激(Low Frequency TENS ；LFTENS)的比較。 研究罹患慢性疼痛為3個月或3個月以上的病人，其中包括合於本評論措施相關的疼痛強度或疼痛緩解的主觀結果之測量。沒有限制任何語言或樣本數大小。若數據摘自摘要、信函、未發表的研究，及研究內容為心絞痛、頭痛、偏頭痛及經痛將不在本評論之收納範圍。

資料收集與分析

數據將被節錄為下列項目：病人和其疼痛細節，研究處理方式，研究的為期期間、設計、方法、主觀疼痛的結果測量，皆進行方法學的質性分析，結果在測量疼痛治療的結果和負面影響，且以原來研究的作者所提出的報告做為結論。每一份摘錄的數據和方法學質性分析，都經過所有評論者做再次的確認。

主要結論

從確定的資料庫中搜索了124篇報告，其中有99篇因不符合預先收納的標準被排除在外。從25個隨機對照試驗合計1281個參與實驗者進行評值，評值內容包括了試驗的各項設計、止痛效果、慢性疼痛的狀況、經皮穿刺神經刺激治療和所有方法學的質性分析。研究的方法和結果非常不ㄧ致且普通不佳。所以做統合分析是不可能的。在所有22個無對照研究中，有13個研究贊成TENS為正向且有效的止痛效果。在多次TENS治療的比較研究中，只有十五分之八的研究認為TENS是積極有效的治療方法。在九個有控制組的研究，其中七個研究比較發現在任何時間點HFTENS 和LFTENS的止痛效果皆無任何差異。

作者結論

本篇評論的結果並無定論;目前已發表的試驗並沒有提供最佳疼痛緩解的刺激參數有關的資料，也沒有告知治療後長期的有效性。所以迫切需要更多的大型中心提供進行TENS在慢性疼痛的隨機對照試驗。

翻譯人

本摘要由三軍總醫院謝凱芝翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

有關經皮神經電刺激用於治療慢性疼痛的成年病患證據尚不充足，所以無法對其成效作出任何的結論。經皮神經電刺激已被醫護專業人員廣泛使用在治療慢性疼痛，往往是作為第一線治療。經皮神經電刺激的設備製造商很多，慢性疼痛患者可透過郵購和門市直接購買。然而，儘管被廣泛使用，但止痛的成效仍然不清楚。搜索過程中確定的研究有124篇;但只有25篇合於收錄標準，但可採用的數據仍不足夠做綜合分析的。在對病人或保健專業人員作以證據為基礎的建議之前，更佳的新試驗設計是需要的。