***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 Whiplash‐associated disorders are common and incur considerable expense in social and economic terms . There are no known effective treatments for those people whose pain and disability persist beyond 3 months . We conducted a r and omized , assessor‐blinded , controlled trial at two centres in Australia . All participants received 3 advice sessions . In addition the experimental group participated in 12 exercise sessions over 6 weeks . Primary outcomes were pain intensity , pain bothersomeness and function measured at 6 weeks and 12 months . Exercise and advice was more effective than advice alone at 6 weeks for all primary outcomes but not at 12 months . The effect of exercise on the 0–10 pain intensity scale was −1.1 ( 95%CI −1.8 to −0.3 , p = 0.005 ) at 6 weeks and −0.2 ( 0.6 to −1.0 , p = 0.59 ) at 12 months ; on the bothersomeness scale the effect was −1.0 ( −1.9 to −0.2 , p = 0.003 ) at 6 weeks and 0.3 ( −0.6 to 1.3 , p = 0.48 ) at 12 months . The effect on function was 0.9 ( 0.3 to 1.6 , p = 0.006 ) at 6 weeks and 0.6 ( −0.1 to 1.4 , p = 0.10 ) at 12 months . High levels of baseline pain intensity were associated with greater treatment effects at 6 weeks and high levels of baseline disability were associated with greater treatment effects at 12 months . In the short‐term exercise and advice is slightly more effective than advice alone for people with persisting pain and disability following whiplash . Exercise is more effective for subjects with higher baseline pain and disability Background The evidence that exercise intervention is effective for treatment of chronic low back pain comes from trials that are not placebo-controlled . Objective The purpose of this study was to investigate the efficacy of motor control exercise for people with chronic low back pain . Design This was a r and omized , placebo-controlled trial . Setting The study was conducted in an outpatient physical therapy department in Australia . Patients The participants were 154 patients with chronic low back pain of more than 12 weeks ’ duration . Intervention Twelve sessions of motor control exercise ( ie , exercises design ed to improve function of specific muscles of the low back region and the control of posture and movement ) or placebo ( ie , detuned ultrasound therapy and detuned short-wave therapy ) were conducted over 8 weeks . Measurements Primary outcomes were pain intensity , activity ( measured by the Patient-Specific Functional Scale ) , and patient 's global impression of recovery measured at 2 months . Secondary outcomes were pain ; activity ( measured by the Patient-Specific Functional Scale ) ; patient 's global impression of recovery measured at 6 and 12 months ; activity limitation ( measured by the Rol and -Morris Disability Question naire ) at 2 , 6 , and 12 months ; and risk of persistent or recurrent pain at 12 months . Results The exercise intervention  improved activity and patient 's global impression of recovery but did not clearly reduce pain at 2 months . The mean effect of exercise on activity ( measured by the Patient-Specific Functional Scale ) was 1.1 points ( 95 % confidence interval [CI]=0.3 to 1.8 ) , the mean effect on global impression of recovery was 1.5 points ( 95 % CI=0.4 to 2.5 ) , and the mean effect on pain was 0.9 points ( 95 % CI=−0.01 to 1.8 ) , all measured on 11-point scales . Secondary outcomes also favored motor control exercise . Limitation Clinicians could not be blinded to the intervention they provided . Conclusions Motor control exercise produced short-term improvements in global impression of recovery and activity , but not pain , for people with chronic low back pain . Most of the effects observed in the short term were maintained at the 6- and 12-month follow-ups In r and omized controlled trials , no single definition of response is ideal for all purpose s. We propose a method to present in a simple fashion the likelihood of response over a full range of response levels , which will facilitate a better underst and ing of clinical trial data . We present the technique called the  cumulative proportion of responders analysis  ( CPRA ) and its application to four pain clinical trial data sets as examples . The CPRA can be used to present the proportion of responders over the entire range of possible cut-off points as a graph . This allows the reader to compare treatment groups at any responder level that is valid for their patient population . Whether as a primary or secondary approach to a clinical trial of pain therapy , the display of data in a CPRA format may be useful in the underst and ing of results and applicability to patient care Background Reporting numbers needed to treat ( NNT ) improves interpretability of trial results . It is unusual that continuous outcomes are converted to numbers of individual responders to treatment ( i.e. , those who reach a particular threshold of change ) ; and deteriorations prevented are only rarely considered . We consider how numbers needed to treat can be derived from continuous outcomes ; illustrated with a worked example showing the methods and challenges . Methods We used data from the UK BEAM trial ( n = 1 , 334 ) of physical treatments for back pain ; originally reported as showing , at best , small to moderate benefits . Participants were r and omised to receive ' best care ' in general practice , the  comparator treatment  ,  or one of three manual and /or exercise treatments : ' best care ' plus manipulation , exercise , or manipulation followed by exercise . We used established consensus thresholds for improvement in Rol and -Morris disability question naire scores at three and twelve months to derive NNTs for improvements and for benefits ( improvements gained+deteriorations prevented ) . Results At three months , NNT estimates ranged from 5.1 ( 95 % CI 3.4 to 10.7 ) to 9.0 ( 5.0 to 45.5 ) for exercise , 5.0 ( 3.4 to 9.8 ) to 5.4 ( 3.8 to 9.9 ) for manipulation , and 3.3 ( 2.5 to 4.9 ) to 4.8 ( 3.5 to 7.8 ) for manipulation followed by exercise . Corresponding between-group mean differences in the Rol and -Morris disability question naire were 1.6 ( 0.8 to 2.3 ) , 1.4 ( 0.6 to 2.1 ) , and 1.9 ( 1.2 to 2.6 ) points . Conclusion In contrast to small mean differences originally reported , NNTs were small and could be attractive to clinicians , patients , and purchasers . NNTs can aid the interpretation of results of trials using continuous outcomes . Where possible , these should be reported alongside mean differences . Challenges remain in calculating NNTs for some continuous outcomes .Trial Registration UK BEAM trial registration : IS RCT N32683578 BACKGROUND Evidence suggests that brief physiotherapy programmes are as effective for acute whiplash-associated disorders as more comprehensive programmes ; however , whether this also holds true for chronic whiplash-associated disorders is unknown . We aim ed to estimate the effectiveness of a comprehensive exercise programme delivered by physiotherapists compared with advice in people with a chronic whiplash-associated disorder . METHODS PROMISE is a two group , pragmatic r and omised controlled trial in patients with chronic ( > 3 months and < 5 years ) grade 1 or 2 whiplash-associated disorder . Participants were r and omly assigned by a computer-generated r and omisation schedule to receive either the comprehensive exercise programme ( 20 sessions ) or advice ( one session and telephone support ) . Sealed opaque envelopes were used to conceal allocation . The primary outcome was pain intensity measured on a 0 - 10 scale . Outcomes were measured at baseline , 14 weeks , 6 months , and 12 months by a masked assessor . Analysis was by intention to treat , and treatment effects were calculated with linear mixed models . The trial is registered with the Australian New Zeal and Clinical Trials Registry , number ACTRN12609000825257 . FINDINGS 172 participants were allocated to either the comprehensive exercise programme  ( n=86 ) or advice group ( n=86 ) ; 157 ( 91 % ) were followed up at 14 weeks , 145 ( 84 % ) at 6 months , and 150 ( 87 % ) at 12 months . A comprehensive exercise programme was not more effective than advice alone for pain reduction in the participants . At 14 weeks the treatment effect on a 0 - 10 pain scale was 0·0 ( 95 % CI -0·7 to 0·7 ) , at 6 months 0·2 ( -0·5 to 1·0 ) , and at 12 months -0·1 ( -0·8 to 0·6 ) . CNS hyperexcitability and symptoms of post-traumatic stress did not modify the effect of treatment . We recorded no serious adverse events . INTERPRETATION We have shown that simple advice is equally as effective as a more intense and comprehensive physiotherapy exercise programme . The need to identify effective and affordable strategies to prevent and treat acute through to chronic whiplash associated disorders is an important health priority . Future avenues of research might include improving underst and ing of the mechanisms responsible for persistent pain and disability , investigating the effectiveness and timing of drugs , and study of content and delivery of education and advice . FUNDING The National Health and Medical Research Council of Australia , Motor Accidents Authority of New South Wales , and Motor Accident Insurance Commission of Queensl and A post-hoc individual patient matching procedure was recently proposed within the context of parallel group r and omized clinical trials ( RCTs ) as a method for estimating treatment effect . In this paper , we consider a post-hoc individual patient matching problem within a  parallel group RCT  as a multi- objective decision-making problem focussing on the trade-off between the quality of individual matches and the overall percentage of matching . Using acute stroke trials as a context , we utilize exact optimization and simulation techniques to investigate a complex relationship between the overall percentage of individual post-hoc matching , the size of the respective RCT , and the quality of matching on variables highly prognostic for a good functional outcome after stroke , as well as the dispersion in these variables . It is empirically confirmed that a high percentage of individual post-hoc matching can only be achieved when the differences in prognostic baseline variables between individually matched subjects within the same pair are sufficiently large and that the unmatched subjects are qualitatively different to the matched ones . It is concluded that the post-hoc individual matching as a technique for treatment effect estimation in parallel-group RCTs should be exercised with caution because of its propensity to introduce significant bias and reduce validity . If used with appropriate caution and thorough evaluation , this approach can complement other viable alternative approaches for estimating the treatment effect Abstract Practice guidelines recommend various types of exercise and manipulative therapy for chronic back pain but there have been few head‐to‐head comparisons of these interventions . We conducted a r and omized controlled trial to compare effects of general exercise , motor control exercise and manipulative therapy on function and perceived effect of intervention in patients with chronic back pain . Two hundred and forty adults with non‐specific low back pain ⩾3 months were allocated to groups that received 8 weeks of general exercise , motor control exercise or spinal manipulative therapy . General exercise included strengthening , stretching and aerobic exercises . Motor control exercise involved retraining specific trunk muscles using ultrasound feedback . Spinal manipulative therapy included joint mobilization and manipulation . Primary outcomes were patient‐specific function ( PSFS , 3–30 ) and global perceived effect ( GPE , −5 to 5 ) at 8 weeks . These outcomes were also measured at 6 and 12 months . Follow‐up was 93 % at 8 weeks and 88 % at 6 and 12 months . The motor control exercise group had slightly better outcomes than the general exercise group at 8 weeks ( between‐group difference : PSFS 2.9 , 95 % CI : 0.9–4.8 ; GPE 1.7 , 95 % CI : 0.9–2.4 ) , as did the spinal manipulative therapy group ( PSFS 2.3 , 95 % CI : 0.4–4.2 ; GPE 1.2 , 95 % CI : 0.4–2.0 ) . The groups had similar outcomes at 6 and 12 months . Motor control exercise and spinal manipulative therapy produce slightly better short‐term function and perceptions of effect than general exercise , but not better medium or long‐term effects , in patients with chronic non‐specific back pain Background Low back pain is a highly prevalent and disabling condition worldwide . Clinical guidelines for the management of patients with acute low back pain recommend first-line treatment consisting of advice , reassurance and simple analgesics . Exercise is also commonly prescribed to these patients . The primary aim of this study was to evaluate the short-term effect of adding the McKenzie method to the first-line care of patients with acute low back pain . Methods A multi-centre r and omized controlled trial with a 3-month follow-up was conducted between September 2005 and June 2008 . Patients seeking care for acute non-specific low back pain from primary care medical practice s were screened . Eligible participants were assigned to receive a treatment programme based on the McKenzie method and first-line care ( advice , reassurance and time-contingent acetaminophen ) or first-line care alone , for 3 weeks . Primary outcome measures included pain ( 0 - 10 Numeric Rating Scale ) over the first seven days , pain at 1 week , pain at 3 weeks and global perceived effect ( -5 to 5 scale ) at 3 weeks . Treatment effects were estimated using linear mixed models . Results One hundred and forty-eight participants were r and omized into study groups , of whom 138 ( 93 % ) completed the last follow-up . The addition of the McKenzie method to first-line care produced statistically significant but small reductions in pain when compared to first-line care alone : mean of -0.4 points ( 95 % confidence interval , -0.8 to -0.1 ) at 1 week , -0.7 points ( 95 % 
    Output:
    
We found no compelling evidence suggesting that outcomes were bimodally distributed for any of the intervention groups .
Responder analysis would not meaningfully alter our interpretation of these data compared with the mean between group difference .
Our findings suggest that bimodal distribution of outcomes should not be assumed in interventions for spinal pain and do not support the automatic prioritization of responder analysis over the between group difference in the evaluation of treatment effectiveness for pain .
PERSPECTIVE Secondary analysis of clinical trials of nonsurgical interventions for spinal pain found no evidence for bimodally distributed outcomes .
The findings do not support the automatic prioritization of responder analyses over the average between group difference in the evaluation of treatment effectiveness for spinal pain