***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: & NA ; The  placebo effect of transcutaneous electrical stimulation was studied in 93 patients in a double‐blind cross‐over trial using a genuine stimulator and a placebo machine . Placebo analgesic effects occurred in 32 % of trials , as compared with 48 % for actual stimulation . The placebo  effect of the transcutaneous electrical stimulator is similar to the placebo effect that is noted in other double‐blind studies in which medicationms are used The aim of this study was to test the efficacy of shortterm transcutaneous electrical nerve stimulation ( TENS ) treatment in chronic pain with respect to pain intensity and patients ’ satisfaction with treatment results . We therefore performed a r and omised controlled trial comparing TENS and sham TENS . Patients , research ers and therapists were blinded for treatment allocation . One hundred and sixty-three patients with chronic pain referred to the Pain Centre entered the study .  Conventional TENS and sham TENS were applied in the segments of pain , for a period of ten days . Outcome measures were pain intensity ( visual analogue scale ) and patients ’ satisfaction with treatment result ( yes or no ) . The proportions of patients satisfied with treatment result differed significantly for TENS compared to sham TENS ( 58 and 42.7 % respectively , x2=3.8 , p=0.05 ) . However , no differences in pain intensity were found for patients treated with TENS or sham TENS . Only for patients satisfied with treatment results pain intensity gradually decrease equally both for TENS and sham TENS with repeated treatment application OBJECTIVE Few non-surgical conditions are more painful than rib fractures . There are a few methods for pain relief in patients with minor rib fractures . METHODS We used a non-steroidal anti-inflammatory drug ( NSAID , Naproxen sodium ) and transcutaneous electrical nerve stimulator ( TENS ) to control pain of the patients with uncomplicated minor rib fractures . One hundred consecutive patients admitted to Kartal Education and Research Hospital Emergency Service , were r and omized into four groups . The patients were assigned to one of the following pain treatments : NSAID , TENS , NSAID plus inactive TENS or placebo . The patients used NSAIDs and placebo four times a day and TENS twice a day for 3 days . All patients were asked to assess their pain level with a scoring system on days 0 , 1 and 3 . RESULTS The most effective treatment was TENS on days 1 and 3 ( P<0.05 ) . Although NSAID and NSAID plus inactive TENS  controlled pain better than placebo on day 1 ( P<0.05 ) , this superiority did not continue to day 3 ( P>0.05 ) . There was no difference between NSAID and NSAID plus inactive TENS in controlling pain on either days 1 or 3 . CONCLUSION We conclude that TENS was more effective than NSAID or placebo in patients with uncomplicated minor rib fractures , because of its prominent and admirable efficacy in reduction of pain Venipuncture continues to be considered a painful and unpleasant experience for those receiving medical treatment . A prospect i ve study investigating whether the application of a transcutaneous electrical nerve stimulator ( TENS ) decreases the complaints of pain and unpleasantness with i.v . needle insertion was conducted using a group of 71 subjects who were double-blinded and r and omized to one of three groups : TENS , placebo-TENS , and control .  This article gives an overview of this research and describes its findings Adequate reporting of r and omized , controlled trials ( RCTs ) is necessary to allow accurate critical appraisal of the validity and applicability of the results . The CONSORT ( Consoli date d St and ards of Reporting Trials ) Statement , a 22-item checklist and flow diagram , is intended to address this problem by improving the reporting of RCTs . However , some specific issues that apply to trials of nonpharmacologic treatments ( for example , surgery , technical interventions , devices , rehabilitation , psychotherapy , and behavioral intervention ) are not specifically addressed in the CONSORT Statement . Furthermore , considerable evidence suggests that the reporting of nonpharmacologic trials still needs improvement . Therefore , the CONSORT group developed an extension of the CONSORT Statement for trials assessing nonpharmacologic treatments . A consensus meeting of 33 experts was organized in Paris , France , in February 2006 , to develop an extension of the CONSORT Statement for trials of nonpharmacologic treatments . The participants extended 11 items from the CONSORT Statement , added 1 item , and developed a modified flow diagram . To allow adequate underst and ing and implementation of the CONSORT extension , the CONSORT group developed this elaboration and explanation document from a review of the literature to provide examples of adequate reporting . This extension , in conjunction with the main CONSORT Statement and other CONSORT extensions , should help to improve the reporting of RCTs performed in this field OBJECTIVE This study examined the optimal stimulation duration of transcutaneous electrical nerve stimulation ( TENS ) for relieving osteoarthritic knee pain  and the duration ( as measured by half-life ) of post-stimulation analgesia . SUBJECTS Thirty-eight patients received either : ( i ) 20 minutes ( TENS20 ) ; ( ii ) 40 minutes ( TENS40 ) ; ( iii ) 60 minutes ( TENS60 ) of TENS ; or ( iv ) 60 minutes of placebo TENS ( TENS(PL ) ) 5 days a week for 2 weeks . METHODS A visual analogue scale recorded the magnitude and pain relief period for up to 10 hours after stimulation . RESULTS By Day10 , a significantly greater cumulative reduction in the visual analogue scale scores was found in the TENS40 ( 83.40 % ) and TENS60 ( 68.37 % ) groups than in the TENS20 ( 54.59 % ) and TENS(PL ) ( 6.14 % ) groups ( p < 0.000 ) , such a group difference was maintained in the 2-week follow-up session ( p < 0.000 ) . In terms of the duration of post-stimulation analgesia period , the duration for the TENS40 ( 256 minutes ) and TENS60 ( 258 minutes ) groups was more prolonged than in the other 2 groups ( TENS20 = 168 minutes , TENS(PL ) = 35 minutes ) by Day10 ( p < 0.000 ) . However , the TENS40 group produced the longest pain relief period by the follow-up session . CONCLUSION 40 minutes is the optimal treatment duration of TENS , in terms of both the magnitude ( VAS scores ) of pain reduction and the duration of post-stimulation analgesia for knee osetoarthritis Thirty patients with chronic pain due to osteoarthrosis ( OA ) of the knee were enrolled in a r and omised double-blind cross-over trial of self-administered transcutaneous electrical nerve stimulation ( TENS ) and placebo TENS . Medication was st and ardised to paracetamol tablets only . As measured on visual analogue scales for pain relief 46 % of patients responded to active therapy and 43 % to placebo . The length of pain relief during active therapy was significantly longer than that during placebo . At the end of the trial more patients wanted to continue using active TENS in preference to placebo or their original medication . Although most of the parameters observed favoured active TENS , it was not possible to establish its clear superiority over placebo , because the response rate to placebo TENS was high and sustained for at least 3 weeks . This trial suggests that a longer study is required to establish the role of TENS as a therapeutic agent in the treatment of the pain of chronic arthritis Objective To assess the value of transcutaneous electrical nerve stimulation ( TENS ) during cervical laser therapy BACKGROUND AND PURPOSE It is not fully understood how transcutaneous electrical nerve stimulation ( TENS ) intensity affects mechanical pain threshold . METHOD Sixty-six healthy volunteers ( 13 male , 53 female ; 132 h and s ) without prior experience of TENS  participated in the study , which comprised a r and omized single-blind controlled trial . TENS was administered for 20 minutes through electrodes ( 25 x 25 mm ) placed on the h and s and forearms with a fixed frequency of 100 Hz and pulse duration of 150 micros . TENS intensity was r and omized and allocated in a concealed manner so that one arm received TENS with stimulation intensity set at participants ' subjective sensory threshold and the other received TENS with stimulation intensity continuously adjusted by physiotherapists to a strong but comfortable non-painful stimulation . Observers were blinded to stimulation intensity levels . RESULTS Mechanical pain threshold increased significantly , by a mean total of 0.79 kg/cm2 ( 95 % confidence interval [ 95 % CI ] : 0.54 - 1.04 ) ( p < 0.001 ) on the strong but comfortable non-painful stimulation side . The mean change in mechanical pain threshold on the sensory threshold side was 0.19 kg/cm2 and did not reach statistical significance ( 95 % CI-0.15 to 0.51 ) . The mean stimulation intensity level for sensory threshold was 6.7 mA ( 95 % CI : 5.65 to 7.83 ) which was significantly lower ( p < 0.001 ) than the mean stimulation intensity for the strong stimulation , which was 20.5 mA ( 95 % CI 16.6 to 24.4 ) , respectively . The strong stimulation levels were , on average , 3.05 times higher than sensory threshold , but individual variations were large ( range 1.2 - 6.1 ) . CONCLUSIONS TENS administered at a strong but comfortable non-painful stimulation intensity increases mechanical pain threshold ipsi-laterally in healthy subjects , whereas TENS administered at sensory threshold intensity does not . TENS may be ineffective if electrodes are placed contralaterally or distant to the pain site and if stimulation intensity levels are not titrated to subjective strong levels . Further clinical trials are needed to clarify if these findings may also be generalized to population s of chronic pain sufferers A double-blind controlled analgesic study was undertaken in out patients suffering acute traumatic pain . One hundred patients completed the study and were r and omly assigned to four treatment groups , each receiving either functioning transcutaneous electrical nerve stimulators ( TENS ) , placebo TENS , acetaminophen with codeine and a functioning TENS , or acetaminophen with codeine and a placebo TENS .  Pain was assessed prior to treatment , at 48 hours , and at one month using a visual analog scale . A statistically significant difference in pain relief occurred between the placebo and functioning TENS groups . The TENS was approximately as effective as acetaminophen ( 300 - 600 mg ) with codeine ( 30 - 60 mg ) but had no side effects .  Transcutaneous electrical nerve stimulators have been shown to be effective in the management of acute traumatic pain and may be indicated for patients who can not be given medications & NA ; This study evaluated the effects of varying frequency , intensity and stimulation site , of transcutaneous electrical nerve stimulation ( TENS ) in an experimental model of pain . In a double‐blind design 240 volunteers were r and omised to one of six experimental TENS groups , a  sham TENS or control ( n=30 per group ; gender balanced ) .  Two TENS frequencies ( 110 or 4 Hz ) and two intensities ( strong but comfortable or highest tolerable ) at a fixed pulse duration ( 200 & mgr;s ) were applied at three sites relative to the measurement site ( segmentally , extrasegmentally or a combination of these ) , for 30 min . Pressure pain thresholds ( PPT ) were measured using a pressure algometer , in the first dorsal interosseous muscle , every 10 min , during stimulation and for a further 30 min . The high frequency , high intensity segmental , and combined stimulation groups , showed rapid onset and significant hypoalgesic effects . This effect was sustained for 20 min post‐stimulation in the high frequency segmental group . All other TENS intervention groups showed hypoalgesic responses similar to the sham TENS group , and none of these groups reached a clinical ly significant hypoalgesic level . Conclusions : The role of TENS frequency , intensity and site are pivotal to achieving optimal hypoalgesic effects , during and after stimulation . Clinical applications of these parameter combinations require further investigations Chronic pain associated with breast cancer treatment is becoming increasingly recognized . Patients with this condition can experience significant physical and psychological morbidity and may benefit from nonpharmacological interventions as part of a multidisciplinary team approach . We compared the effectiveness of transcutaneous electrical nerve stimulation ( TENS ) , transcutaneous spinal electroanalgesia ( TSE ) , and a placebo ( sham TSE ) in a r and omized controlled trial . The study sample comprised 41 women with chronic pain following breast cancer treatment , and outcome measures included pain report , pain relief , pain interference , anxiety and depression , arm mobility , and analgesic consumption . There was little evidence to suggest that TENS or TSE were more effective than placebo . All three interventions had beneficial effects on both pain report and quality of life , a finding that may be due to either psychophysical improvements result ing from the personal interaction involved in the treatment or a placebo response . Although electrical stimulation appears to be well tolerated in this population , further research is needed to establish its effectiveness for chronic cancer treatment-related pain Thirty-six non-hospitalized subjects with chronic pain from OA of the knee participated in an evaluation of transcutaneous electrical nerve stimulation ( TENS ) and naproxen , an NSAID . All pre-experiment 
    Output:
    
Suboptimal dosing of TENS and inappropriate outcome assessment were particularly prevalent weaknesses indicating low fidelity .
Poor implementation fidelity was identified as a significant source of bias in systematic review s of TENS studies and might explain lack of consistent treatment effects of TENS in pain .