***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: Abstract This single-blind r and omised clinical trial compared osteopathic manipulative treatment with chemonucleolysis ( used as a control of known efficacy ) for symptomatic lumbar disc herniation . Forty patients with sciatica due to this diagnosis ( confirmed by imaging ) were treated either by chemonucleolysis or manipulation . Outcomes ( leg pain , back pain and self-reported disability ) were measured at 2 weeks , 6 weeks and 12 months . The mean values for all outcomes improved in both groups . By 12 months , there was no statistically significant difference in outcome between the treatments , but manipulation produced a statistically significant greater improvement for back pain and disability in the first few weeks . A similar number from both groups required additional orthopaedic intervention ; there were no serious complications . Crude cost analysis suggested an overall financial advantage from manipulation . Because osteopathic manipulation produced a 12-month outcome that was equivalent to chemonucleolysis , it can be considered as an option for the treatment of  symptomatic lumbar disc herniation  , at least in the absence of clear indications for surgery . Further study into the value of manipulation at a more acute stage is warranted Therapeutic trials often attempt to “ blind ” patient and investigator to the true nature of treatments received , reducing the influences of conscious or subconscious prejudices . In drug trials , this is accomplished with placebo tablets , but blinding in trials of physical treatments is more problematic . This issue arose in a clinical trial of transcutaneous electrical nerve stimulation ( TENS ) for patients with chronic low back pain . Several study design features were incorporated to promote blinding : use of sham TENS units visually identical with real units , exclusion of potential subjects with previous TENS experience , avoidance of a crossover design and use of identical visit frequency , instructions and modifications in electrode placement . Subjects were asked not to discuss treatments with the clinicians who performed outcome assessment s. Both patients and clinicians were asked to guess actual treatment assignments at the trial 's end . Every patient in the true TENS group believed the unit was functioning properly , but the degree of certainty varied . In the sham TENS group , 84 % also believed they had functioning units , but their certainty was significantly less than in the active treatment group . Differences in patient perceptions did not affect compliance , as the two groups had similar dropout rates , appointment compliance , days of TENS use and daily duration of TENS use . Clinicians guessed treatments correctly 61 % of the time ( as opposed to 50 % expected by chance ) , again suggesting partial success in blinding . These efforts at blinding may partly explain the negative trial results for TENS efficacy . We conclude that complete blinding is difficult to achieve because of sensory difference in treatment and unintended communication between patient and examiner . Nonetheless , trials of physical treatments can achieve partial blinding with the techniques described here , and the success of blinding can be assessed with simple questions at study completion Objective : To determine the clinical effects of the treatment of lumbar disc herniation with herbal magnetic corsets . Design : A r and omized control trial . Setting : The outpatient and inpatient departments of the Rehabilitation Center of the West China Hospital . Patients : Sixty patients with clinical ly diagnosed lumbar disc herniation were included in the study . Interventions : Both groups received lumbar traction , medium frequency electrotherapy and massage , whereas the experimental group wore herbal magnetic corsets in addition . Main outcome measures : Pain and lumbar function were assessed before treatment and at one week , two weeks and four weeks after intervention . Results : Both groups reported improvements in pain and lumbar function after treatment ( P 0.05 or P 0.001 ) . However , the experimental group reported gradually increasing relief over time leading to a better curative effect than observed in the control group ( P 0.05 for visual analogue scale or P 0.001 for lumbar function ) . Conclusion : Herbal magnetic corsets can facilitate the reduction of pain caused by lumbar disc herniation and can improve lumbar function . This is a safe and effective non-operative therapeutic option for treatment of lumbar disc herniation R and omized controlled clinical trials are conducted to determine whether differences of clinical importance exist between selected treatment regimens . When statistical analysis of the study data finds a P value greater than 5 % , it is convention to deem the assessed difference nonsignificant . Just because convention dictates that such study findings be termed nonsignificant , or negative , however , it does not necessarily follow that the study found nothing of clinical importance . Subject sample s used in controlled trials tend to be too small . The studies therefore lack the necessary power to detect real , and clinical ly worthwhile , differences in treatment . Freiman et al. found that only 30 % of a sample of 71 trials published in the New Engl and Journal of Medicine in 1978 - 79 with a P value greater than 10 % were large enough to have a 90 % chance of detecting even a 50 % difference in the effectiveness of the treatments being compared , and they found no improvement in a similar sample of trials published in 1988 . It is therefore wrong and unwise to interpret so many negative trials as providing evidence of the ineffectiveness of new treatments . One must instead seriously question whether the absence of evidence is a valid justification for inaction . Efforts must be made to look for quantification of an association rather than just a P value , especially when the risks under investigation are small . The authors cite a recent trial comparing octreotide and sclerotherapy in patients with variceal bleeding  , as well as the overview of clinical trials evaluating fibrinolytic treatment for preventing reinfa rct ion after acute myocardial infa rct ion as examples BACKGROUND Lumbar-disk surgery often is performed in patients who have sciatica that does not resolve within 6 weeks , but the optimal timing of surgery is not known . METHODS We r and omly assigned 283 patients who had had severe sciatica for 6 to 12 weeks to early surgery  or to prolonged conservative treatment with surgery if needed . The primary outcomes were the score on the Rol and Disability Question naire , the score on the visual-analogue scale for leg pain , and the patient 's report of perceived recovery during the first year after r and omization . Repeated- measures analysis according to the intention-to-treat principle was used to estimate the outcome curves for both groups . RESULTS Of 141 patients assigned to undergo early surgery  , 125 ( 89 % ) underwent  microdiskectomy  after a mean of 2.2 weeks . Of 142 patients design ated for conservative treatment , 55 ( 39 % ) were treated surgically after a mean of 18.7 weeks . There was no significant overall difference in disability scores during the first year ( P=0.13 ) . Relief of leg pain was faster for patients assigned to early surgery ( P<0.001 ) . Patients assigned to early surgery also reported a faster rate of perceived recovery ( hazard ratio , 1.97 ; 95 % confidence interval , 1.72 to 2.22 ; P<0.001 ) . In both groups , however , the probability of perceived recovery after 1 year of follow-up was 95 % . CONCLUSIONS The 1-year outcomes were similar for patients assigned to early surgery and those assigned to conservative treatment with eventual surgery if needed , but the rates of pain relief and of perceived recovery were faster for those assigned to early surgery . ( Current Controlled Trials number , IS RCT N26872154 [ controlled-trials.com ] . ) BACKGROUND Although epidural corticosteroid injections are commonly used for sciatica , their efficacy has not been established . METHODS In a r and omized , double-blind trial , we administered up to three epidural injections of methylprednisolone acetate ( 80 mg in 8 ml of isotonic saline ) or isotonic saline ( 1 ml ) to 158 patients with sciatica due to a herniated nucleus pulposus . All patients had Oswestry disability scores higher than 20 ( on a scale of 1 to 100 , with scores of 20 or less indicating minimal disability , and higher scores greater disability ) . RESULTS At three weeks , the Oswestry score had improved by a mean of -8.0 in the methylprednisolone group and -5.5 in the placebo group ( 95 percent confidence interval for the difference , -7.1 to 2.2 ) . Differences in improvements between the groups were not significant , except for improvements in the finger-to-floor distance ( P=0.006 ) and sensory deficits ( P=0.03 ) , which were greater in the methylprednisolone group . After six weeks , the only significant difference was the improvement in leg pain , which was greater in the methylprednisolone group ( P=0.03 ) . After three months , there were no significant differences between the groups . The Oswestry score had improved by a mean of -17.3 in the methylprednisolone group and -15.4 in the placebo group ( 95 percent confidence interval for the difference , -9.3 to 5.4 ) . At 12 months , the cumulative probability of back surgery was 25.8 percent in the methylprednisolone group and 24.8 percent in the placebo group ( P=0.90 ) . CONCLUSIONS Although epidural injections of methylprednisolone may afford short-term improvement in leg pain and sensory deficits in patients with sciatica due to a herniated nucleus pulposus , this treatment offers no significant functional benefit , nor does it reduce the need for surgery Objectives To evaluate the effects of early lumbar disc surgery compared with prolonged conservative care for patients with sciatica over two years of follow-up . Design R and omised controlled trial . Setting Nine Dutch hospitals . Participants 283 patients with 6 - 12 weeks of sciatica . Interventions Early surgery or an intended six months of continued conservative treatment , with delayed surgery if needed . Main outcome measures Scores from Rol and disability question naire for sciatica , visual analogue scale for leg pain , and Likert self rating scale of global perceived recovery . Results Of the 141 patients assigned to undergo early surgery  , 125 ( 89 % ) underwent  microdiscectomy . Of the 142 patients assigned to conservative treatment , 62 ( 44 % ) eventually required surgery , seven doing so in the second year of follow-up . There was no significant overall difference between treatment arms in disability scores during the first two years ( P=0.25 ) . Improvement in leg pain was faster for patients r and omised to early surgery , with a significant difference between “ areas under the curves ” over two years ( P=0.05 ) . This short term benefit of early surgery was no longer significant by six months and continued to narrow between six months and 24 months . Patient satisfaction decreased slightly between one and two years for both groups . At two years 20 % of all patients reported an unsatisfactory outcome . Conclusions Early surgery achieved more rapid relief of sciatica than conservative care , but outcomes were similar by one year and these did not change during the second year . Trial Registry IS RCT No 26872154 We analysed 113 reports published in 1980 in a sample of medical journals to relate features of study design to the magnitude of gains attributed to new therapies over old . Overall we rated 87 per cent of new therapies as improvements over st and ard therapies . The mean gain ( measured by the Mann-Whitney statistic ) was relatively constant across study design s , except for non-r and omized controlled trials with sequential assignment to therapy , which showed a significantly higher likelihood that a patient would do better on the innovation than on st and ard therapy ( p = 0.004 ) . R and omized controlled trials that did not use a double-blind design had a higher likelihood of showing a gain for the innovation than did double-blind trials ( p = 0.02 ) . Any evaluation of an innovation may include both bias and the true efficacy of the new therapy , therefore we may consider making adjustments for the average bias associated with a study design . When interpreting an evaluation of a new therapy , readers should consider the impact of the following average adjustments to the Mann-Whitney statistic : for trials with non-r and om sequential assignment a decrease of 0.15 , for non-double-blind r and omized controlled trials a decrease of 0.11 Background The Cochrane Highly Sensitive Search Strategy ( HSSS ) , which contains three phases , is widely used to identify R and omized Controlled Trials ( RCTs ) in MEDLINE . Lefebvre and Clarke suggest that review ers might consider using four revisions of the HSSS . The objective of this study is to vali date these four revisions : combining the free text terms volunteer , crossover , versus , and the Medical Subject Heading CROSS-OVER STUDIES with the top two phases of the HSSS , respectively . Methods We replicated the subject search for 61 Cochrane review s. The included studies of each review that were indexed in MEDLINE were pooled together by review and then combined with the subject search and each of the four proposed search strategies , the top two phases of the HSSS , and all three phases of the HSSS . These retrievals were used to calculate the sensitivity and precision of each of the six search strategies for each review . Results Across the 61 review s , the search term versus combined with the top two phases of the HSSS was able to find 3 more included studies than the top two phases of the HSSS alone , or in combination with any of the other proposed search terms , but at the expense of missing 56 relevant articles that would be found if all three phases of the HSSS were used . The estimated time needed to finish a review is 1086 hours for all three phases of the HSSS , 823 hours for the strategy versus , 818 hours for the first two phases of the HSSS or any of the other three proposed strategies . Conclusion This study shows that compared to the first two phases of the HSSS , adding the term versus to the top two phases of the HSSS balances the sensitivity and precision in the review s studied here to some extent 
    Output:
    
Individual high- quality trials provided moderate evidence that  stabilization exercises  are more effective than no treatment , that manipulation is more effective than sham manipulation for people with acute symptoms and an intact anulus , and that no difference exists among traction , laser , and ultrasound .
Adverse events were associated with traction  ( pain , anxiety , lower limb weakness , and fainting ) and ibuprofen ( gastrointestinal events ) .
Advice is less effective than  microdiscectomy  in the short term but equally effective in the long term for people who have LDHR .
Moderate evidence favors stabilization exercises over no treatment , manipulation over sham manipulation , and the addition of mechanical traction to medication and electrotherapy .
There was no difference among traction , laser , and ultrasound .
Adverse events were associated with traction and ibuprofen .