BACKGROUND: Chronic pain, considered to be pain lasting more than three months, is a common and often difficult to treat condition that can significantly impact upon function and quality of life. Treatment typically includes pharmacological and non-pharmacological approaches. Transcutaneous electrical nerve stimulation (TENS) is an adjunct non-pharmacological treatment commonly recommended by clinicians and often used by people with pain.
OBJECTIVES: To provide an overview of evidence from Cochrane Reviews of the effectiveness of TENS to reduce pain in adults with chronic pain (excluding headache or migraine).To provide an overview of evidence from Cochrane Reviews of the safety of TENS when used to reduce pain in adults with chronic pain (excluding headache or migraine).To identify possible sources of inconsistency in the approaches taken to evaluating the evidence related to TENS for chronic pain (excluding headache or migraine) in the Cochrane Library with a view to recommending strategies to improve consistency in methodology and reporting.To highlight areas of remaining uncertainty regarding the effectiveness of TENS for chronic pain (excluding headache or migraine) with a view to recommending strategies to reduce any uncertainty.
METHODS: Search methodsWe searched the Cochrane Database of Systematic Reviews (CDSR), in the Cochrane Library, across all years up to Issue 11 of 12, 2018.Selection of reviewsTwo authors independently screened the results of the electronic search by title and abstract against inclusion/exclusion criteria. We included all Cochrane Reviews of randomised controlled trials (RCTs) assessing the effectiveness of TENS in people with chronic pain. We included reviews if they investigated the following: TENS versus sham; TENS versus usual care or no treatment/waiting list control; TENS plus active intervention versus active intervention alone; comparisons between different types of TENS; or TENS delivered using different stimulation parameters.Data extraction and analysisTwo authors independently extracted relevant data, assessed review quality using the AMSTAR checklist and applied GRADE judgements where required to individual reviews. Our primary outcomes included pain intensity and nature/incidence of adverse effects; our secondary outcomes included disability, health-related quality of life, analgesic medication use and participant global impression of change.
MAIN RESULTS: We included nine reviews investigating TENS use in people with defined chronic pain or in people with chronic conditions associated with ongoing pain. One review investigating TENS for phantom or stump-associated pain in people following amputation did not have any included studies. We therefore extracted data from eight reviews which represented 51 TENS-related RCTs representing 2895 TENS-comparison participants entered into the studies.The included reviews followed consistent methods and achieved overall high scores on the AMSTAR checklist. The evidence reported within each review was consistently rated as very low quality. Using review authors' assessment of risk of bias, there were significant methodological limitations in included studies; and for all reviews, sample sizes were consistently small (the majority of studies included fewer than 50 participants per group).Six of the eight reviews presented a narrative synthesis of included studies. Two reviews reported a pooled analysis.Primary and secondary outcomes One review reported a beneficial effect of TENS versus sham therapy at reducing pain intensity on a 0 to 10 scale (MD -1.58, 95% CI -2.08 to -1.09, P < 0.001, I² = 29%, P = 0.22, 5 studies, 207 participants). However the quality of the evidence was very low due to significant methodological limitations and imprecision. A second review investigating pain intensity performed a pooled analysis by combining studies that compared TENS to sham with studies that compared TENS to no intervention (SMD -0.85, 95% CI -1.36 to -0.34, P = 0.001, I² = 83%, P < 0.001). This pooled analysis was judged as offering very low quality evidence due to significant methodological limitations, large between-trial heterogeneity and imprecision. We considered the approach of combining sham and no intervention data to be problematic since we would predict these different comparisons may be estimating different true effects. All remaining reviews also reported pain intensity as an outcome measure; however the data were presented in narrative review form only.Due to methodological limitation and lack of useable data, we were unable to offer any meaningful report on the remaining primary outcome regarding nature/incidence of adverse effects, nor for the remaining secondary outcomes: disability, health-related quality of life, analgesic medication use and participant global impression of change for any comparisons.We found the included reviews had a number of inconsistencies when evaluating the evidence from TENS studies. Approaches to assessing risk of bias around the participant, personnel and outcome-assessor blinding were perhaps the most obvious area of difference across included reviews. We also found wide variability in terms of primary and secondary outcome measures, and inclusion/exclusion criteria for studies varied with respect to including studies which assessed immediate effects of single interventions.
AUTHORS' CONCLUSIONS: We found the methodological quality of the reviews was good, but quality of the evidence within them was very low. We were therefore unable to conclude with any confidence that, in people with chronic pain, TENS is harmful, or beneficial for pain control, disability, health-related quality of life, use of pain relieving medicines, or global impression of change. We make recommendations with respect to future TENS study designs which may meaningfully reduce the uncertainty relating to the effectiveness of this treatment in people with chronic pain.
BACKGROUND: This article is the first in a series presenting the strongest published evidence for physical and rehabilitation medicine (PRM) to date coming from the Cochrane Collaboration. The intent of the series is to stimulate ideas for reviews and research in neglected areas of PRM.
AIM: To systematically review the rehabilitation contents of the Cochrane Collaboration on disabilities due to spinal disorders or pain syndromes in adults.
METHODS: The Cochrane Database of Systematic Reviews was searched at the end of June 2013 for articles relevant for PRM about disabilities resulting from spinal disorders or pain syndromes in adults. Retrieved papers were classified according to the PRM approach: active therapies, which require active participation by patients to achieve treatment goals, and passive treatments, which rely on the application of external forces. The quality of the reviews was checked against the AMSTAR checklist.
RESULTS: Reviews on spinal disorders or pain syndromes were found in the Cochrane Back Group (CBG) and in the Pain, Palliative and Supportive Care Group (CPPSCG). Thirty-eight (42.8%) of 89 Cochrane reviews in the CBG and 7 (2.4%) of 293 Cochrane reviews in the CPPSCG were included. All were of high quality (range, 8-11 points out of 11 on the AMSTAR checklist). The contents of the reviews are given in detail.
CONCLUSION: This review presents an overview of the current evidence for PRM in the treatment of disabilities due to spinal disorders or pain syndromes in adults. Within PRM there is ample space for research in the Cochrane Collaboration and for producing original studies (randomized controlled trials [RCTs]).
CLINICAL REHABILITATION IMPACT: To apply evidence-based clinical practice, clinicians must be familiar with the current best evidence.
Cancer-related fatigue, a subjective feeling of a distinctive physical, emotional and/or cognitive tiredness, is a common phenomenon in patients with cytotoxic chemotherapy or radiotherapy. Research on cancer-related fatigue has been intensified in the last decade. The objective of this work was to give an overview of the effectiveness of non-pharmacological interventions for cancer-related fatigue. Therefore, the databases of the Cochrane Library, PubMed, CINAHL and DAHTA were searched for systematic reviews. Two persons independently selected the reviews and assessed the methodological quality. We used the measurement tool AMSTAR to assess the methodological quality of each systematic review. The results were summarised in a qualitative synthesis. A total of 24 reviews were included in the analysis. The results show that physical activity and psycho-social support can reduce fatigue in cancer patients. Particularly, nurse-led fatigue specific interventions proved to be effective. Currently the evidence for other intervention types is weak; however there exist some promising approaches. Despite a large number of randomised clinical trials as well as systematic reviews the evidence base is still deficient in many respects. The results can be used by nurses in clinical care, counselling and education of cancer patients.
Acupuncture is often recommended for obstetrical and gynecological conditions but the evidence is confusing. We aim to summarize all recent systematic reviews in this area. Western and Asian electronic databases were searched for systematic reviews of any type of acupuncture for any type of gynecological conditions. Our own files were hand-searched. Systematic reviews of any type of acupuncture for any type of gynecological conditions were included. Non-systematic reviews and systematic reviews published before 2004 were excluded. No language restrictions were applied. Data were extracted according to predefined criteria and analysed narratively. Twenty-four systematic reviews were included. They relate to a wide range of gynecological conditions: hot flashes, conception, dysmenorrhea, premenstrual syndrome, nausea/vomiting, breech presentation, back pain during pregnancy, and procedural pain. Nine systematic reviews arrived with clearly positive conclusions; however, there were many contradictions and caveats. The evidence for acupuncture as a treatment of obstetrical and gynecological conditions remains limited.
Acupuncture is commonly used for pain control, but doubts about its effectiveness and safety remain. This review was aimed at critically evaluating systematic reviews of acupuncture as a treatment of pain and at summarizing reports of serious adverse effects published since 2000. Literature searches were carried out in 11 databases without language restrictions. Systematic reviews were considered for the evaluation of effectiveness and case series or case reports for summarizing adverse events. Data were extracted according to predefined criteria. Fifty-seven systematic reviews met the inclusion criteria. Four were of excellent methodological quality. Numerous contradictions and caveats emerged. Unanimously positive conclusions from more than one high-quality systematic review existed only for neck pain. Ninety-five cases of severe adverse effects including 5 fatalities were included. Pneumothorax and infections were the most frequently reported adverse effects. In conclusion, numerous systematic reviews have generated little truly convincing evidence that acupuncture is effective in reducing pain. Serious adverse effects continue to be reported. Numerous reviews have produced little convincing evidence that acupuncture is effective in reducing pain. Serious adverse events, including deaths, continue to be reported.
Systematic reviews of acupuncture have tended to support its use, but few applied rigorous inclusion criteria. We tested the credibility of conclusions of systematic reviews of acupuncture published since 1996 by applying rigorous inclusion criteria. Reinterpretation used randomised and double blind trials with valid outcomes or design, and with information available from at least four trials or from 200 patients. Qualified support for acupuncture was originally reported in 12 out of 35 systematic reviews, and strong support was found in another six. Applying stricter inclusion criteria, however, showed that none of the 35 reviews supported acupuncture, predominantly because there were too few patients in the randomised, double blind studies. Six reviews with more than 200 patients in randomised, double blind studies had good evidence of no benefit. Systematic reviews of acupuncture have overstated effectiveness by including studies likely to be biased. They provide no robust evidence that acupuncture works for any indication.
Chronic pain, considered to be pain lasting more than three months, is a common and often difficult to treat condition that can significantly impact upon function and quality of life. Treatment typically includes pharmacological and non-pharmacological approaches. Transcutaneous electrical nerve stimulation (TENS) is an adjunct non-pharmacological treatment commonly recommended by clinicians and often used by people with pain.
OBJECTIVES:
To provide an overview of evidence from Cochrane Reviews of the effectiveness of TENS to reduce pain in adults with chronic pain (excluding headache or migraine).To provide an overview of evidence from Cochrane Reviews of the safety of TENS when used to reduce pain in adults with chronic pain (excluding headache or migraine).To identify possible sources of inconsistency in the approaches taken to evaluating the evidence related to TENS for chronic pain (excluding headache or migraine) in the Cochrane Library with a view to recommending strategies to improve consistency in methodology and reporting.To highlight areas of remaining uncertainty regarding the effectiveness of TENS for chronic pain (excluding headache or migraine) with a view to recommending strategies to reduce any uncertainty.
METHODS:
Search methodsWe searched the Cochrane Database of Systematic Reviews (CDSR), in the Cochrane Library, across all years up to Issue 11 of 12, 2018.Selection of reviewsTwo authors independently screened the results of the electronic search by title and abstract against inclusion/exclusion criteria. We included all Cochrane Reviews of randomised controlled trials (RCTs) assessing the effectiveness of TENS in people with chronic pain. We included reviews if they investigated the following: TENS versus sham; TENS versus usual care or no treatment/waiting list control; TENS plus active intervention versus active intervention alone; comparisons between different types of TENS; or TENS delivered using different stimulation parameters.Data extraction and analysisTwo authors independently extracted relevant data, assessed review quality using the AMSTAR checklist and applied GRADE judgements where required to individual reviews. Our primary outcomes included pain intensity and nature/incidence of adverse effects; our secondary outcomes included disability, health-related quality of life, analgesic medication use and participant global impression of change.
MAIN RESULTS:
We included nine reviews investigating TENS use in people with defined chronic pain or in people with chronic conditions associated with ongoing pain. One review investigating TENS for phantom or stump-associated pain in people following amputation did not have any included studies. We therefore extracted data from eight reviews which represented 51 TENS-related RCTs representing 2895 TENS-comparison participants entered into the studies.The included reviews followed consistent methods and achieved overall high scores on the AMSTAR checklist. The evidence reported within each review was consistently rated as very low quality. Using review authors' assessment of risk of bias, there were significant methodological limitations in included studies; and for all reviews, sample sizes were consistently small (the majority of studies included fewer than 50 participants per group).Six of the eight reviews presented a narrative synthesis of included studies. Two reviews reported a pooled analysis.Primary and secondary outcomes One review reported a beneficial effect of TENS versus sham therapy at reducing pain intensity on a 0 to 10 scale (MD -1.58, 95% CI -2.08 to -1.09, P < 0.001, I² = 29%, P = 0.22, 5 studies, 207 participants). However the quality of the evidence was very low due to significant methodological limitations and imprecision. A second review investigating pain intensity performed a pooled analysis by combining studies that compared TENS to sham with studies that compared TENS to no intervention (SMD -0.85, 95% CI -1.36 to -0.34, P = 0.001, I² = 83%, P < 0.001). This pooled analysis was judged as offering very low quality evidence due to significant methodological limitations, large between-trial heterogeneity and imprecision. We considered the approach of combining sham and no intervention data to be problematic since we would predict these different comparisons may be estimating different true effects. All remaining reviews also reported pain intensity as an outcome measure; however the data were presented in narrative review form only.Due to methodological limitation and lack of useable data, we were unable to offer any meaningful report on the remaining primary outcome regarding nature/incidence of adverse effects, nor for the remaining secondary outcomes: disability, health-related quality of life, analgesic medication use and participant global impression of change for any comparisons.We found the included reviews had a number of inconsistencies when evaluating the evidence from TENS studies. Approaches to assessing risk of bias around the participant, personnel and outcome-assessor blinding were perhaps the most obvious area of difference across included reviews. We also found wide variability in terms of primary and secondary outcome measures, and inclusion/exclusion criteria for studies varied with respect to including studies which assessed immediate effects of single interventions.
AUTHORS' CONCLUSIONS:
We found the methodological quality of the reviews was good, but quality of the evidence within them was very low. We were therefore unable to conclude with any confidence that, in people with chronic pain, TENS is harmful, or beneficial for pain control, disability, health-related quality of life, use of pain relieving medicines, or global impression of change. We make recommendations with respect to future TENS study designs which may meaningfully reduce the uncertainty relating to the effectiveness of this treatment in people with chronic pain.
