***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: Given that retention rates for weight-loss trials have not significantly improved in the past 20 years , identifying effective techniques to enhance retention is critical . This paper describes a conceptual and practical advance that may have improved retention in a behavioral weight-loss trial-the novel application of motivational interviewing techniques to diffuse ambivalence during interactive group-based orientation sessions prior to r and omization . These orientation sessions addressed ambivalence about making eating and exercise behavior changes , ambivalence about joining a r and omized controlled trial , and unrealistic weight-loss expectations . During these sessions , overweight and obese men and women learned about the health benefits of modest weight loss as well as trial design , the importance of a control condition , r and om assignment and the impact of dropouts . Participants were then divided into groups of three or four , and asked to generate two pros and two cons of being assigned to a control condition and an active condition . Participants shared their pros and cons with the larger group , while the investigator asked open-ended questions , engaged in reflective listening and avoided taking a ' pro-change ' position . Retention was high , with 96 % of the participants ( N = 162 ) completing 18-month clinic visits Abstract Objective To estimate the effect of adding exercise classes , spinal manipulation delivered in NHS or private premises , or manipulation followed by exercise to “ best care ” in general practice for patients consulting with back pain . Fig 1 Progress of the UK BEAM trial Design Pragmatic r and omised trial with factorial design . Setting 181 general practice s in Medical Research Council General Practice Research Framework ; 63 community setting s around 14 centres across the United Kingdom . Participants 1334 patients consulting their general practice s about low back pain . Main outcome measures Scores on the Rol and Morris disability question naire at three and 12 months , adjusted for centre and baseline scores . Results All groups improved over time . Exercise  improved mean disability question naire scores at three months by 1.4 ( 95 % confidence interval 0.6 to 2.1 ) more than “ best care . ” For manipulation the additional improvement was 1.6 ( 0.8 to 2.3 ) at three months and 1.0 ( 0.2 to 1.8 ) at 12 months . For manipulation followed by exercise the additional improvement was 1.9 ( 1.2 to 2.6 ) at three months and 1.3 ( 0.5 to 2.1 ) at 12 months . No significant differences in outcome occurred between manipulation in NHS premises and in private premises . No serious adverse events occurred . Conclusions Relative to “ best care ” in general practice , manipulation followed by exercise achieved a moderate benefit at three months and a small benefit at 12 months ; spinal manipulation achieved a small to moderate benefit at three months and a small benefit at 12 months ; and exercise achieved a small benefit at three months but not 12 months This study examined the role of a Medication Event Monitoring System ( MEMS ) to assess pill-taking behavior and enhance compliance within a r and omized trial of bupropion-SR for smoking cessation . Female participants ( N = 97 ) received MEMS bottles containing bupropion-SR 150 mg or placebo , to be taken twice daily . A r and omly selected “ feedback ” group of participants was told about the recording device in the bottle cap and received weekly graphic feedback showing their pill-taking behavior with specific instructions for improving compliance . A “ no-feedback ” group was not informed about the MEMS bottles , and did not receive further instruction or feedback beyond the st and ard dosing instructions . Compliance outcomes were the total doses taken and number of doses taken within the prescribed time interval . Results indicated significantly higher compliance over time for the feedback group . Participation in the feedback group predicted higher compliance beyond demographic , smoking , and health belief variables , suggesting significant benefit in providing brief feedback and instruction throughout the medication regimen Abstract Objective : To evaluate the use of a computerised support system for decision making for implementing evidence based clinical guidelines for the management of asthma and angina in adults in primary care . Design : A before and after pragmatic cluster r and omised controlled trial utilising a two by two incomplete block design . Setting : 60 general practice s in north east Engl and . Participants : General practitioners and practice nurses in the study practice s and their patients aged 18 or over with angina or asthma . Main outcome measures : Adherence to the guidelines , based on review of case notes and patient reported generic and condition specific outcome measures . Results : The computerised decision support system had no significant effect on consultation rates , process of care measures ( including prescribing ) , or any patient reported outcomes for either condition . Levels of use of the software were low . Conclusions : No effect was found of computerised evidence based guidelines on the management of asthma or angina in adults in primary care . This was probably due to low levels of use of the software , despite the system being optimised as far as was technically possible . Even if the technical problems of producing a system that fully supports the management of chronic disease were solved , there remains the challenge of integrating the systems into clinical encounters where busy practitioners manage patients with complex , multiple conditions OBJECTIVE To determine the effect of a voucher for free mammography on compliance with recommended mammography screening guidelines . STUDY DESIGN Vouchers for free mammography distributed to a r and om sample of women over the age of 50 in two rural southern Minnesota counties . The vouchers were good for one year . Baseline and follow-up data were collected and rates of compliance with current mammography guidelines were observed for the voucher group and a control group of women living in the same counties . METHODS Logistic regression models were used to estimate the effect of the voucher on compliance with mammography guidelines and the impact of factors potentially influencing the effectiveness of the voucher . PRINCIPAL FINDINGS The voucher improved mammography rates primarily through increasing screening among women who were out of compliance at baseline . CONCLUSIONS Vouchers , even when distributed r and omly within a population of rural Midwestern women , can significantly improve compliance rates .  Vouchers are no less effective a means of increasing screening among vulnerable women than among other women Background Postal question naires are widely used to collect data in healthcare research but a poor response rate may reduce the validity and reliability of results . There was a lack of evidence available relating to use of a monetary incentive to improve the response rate in the healthcare setting . Methods The MRC ORACLE Children Study is assessing the health and development of nearly 9000 seven year old children whose mothers ' joined the MRC ORACLE Trial . We carried out a r and omised controlled trial of inclusion of monetary incentive ( five pound voucher redeemable at many high street stores ) with the reminder question naire to parents . This trial took place between April 2002 and November 2003 . When the parents were sent the reminder question naire about their child 's health and development they were r and omly assigned by concealed computer-generated allocation stratified by week of birthday to receive a five pound voucher or no incentive . The population were 722 non-responders to the initial mailing of a 12-page question naire . Main outcome measures : Difference in response rate between the two groups . Results Inclusion of the voucher with the reminder question naire result ed in a 11.7%(95 % CI 4.7 % to 18.6 % ) improvement in the response rate between the two groups . Conclusion This improvement in response rate and hence the validity and reliability of results obtained appears to be justified ethically and financially OBJECTIVE To test the efficacy of a prevention intervention to reduce sexual risk behavior among Latino adolescents . DESIGN R and omized controlled trial from April 2000 through March 2003 , with data collection before and after intervention and at 3 , 6 , and 12 months . SETTING Northeast Philadelphia schools . PARTICIPANTS Latinos aged 13 through 18 years ( 249 males and 304 females ) ; 81.6 % retained at 12-month follow-up . INTERVENTIONS The HIV and health-promotion control interventions consisted of six 50-minute modules delivered by adult facilitators to small , mixed-gender groups  in English or Spanish . Main Outcome Measure Self-reported sexual behavior . RESULTS Analyses using generalized estimation equations over the follow-up period revealed that adolescents in the HIV intervention were less likely to report sexual intercourse ( odds ratio , 0.66 ; 95 % confidence interval [ CI ] , 0.46 - 0.96 ) , multiple partners ( odds ratio , 0.53 ; 95 % CI , 0.31 - 0.90 ) , and days of unprotected intercourse ( relative risk , 0.47 ; 95 % CI , 0.26 - 0.84 ) and more likely to report using condoms consistently ( odds ratio , 1.91 ; 95 % CI , 1.24 - 2.93 ) . Baseline sexual experience and language use moderated intervention efficacy . Adolescents assigned to the HIV intervention who were sexually inexperienced at baseline reported fewer days of unprotected sex ( relative risk , 0.22 ; 95 % CI , 0.08 - 0.63 ) ; Spanish speakers were more likely to have used a condom at last intercourse ( odds ratio , 4.73 ; 95 % CI , 1.72 - 12.97 ) and had a greater proportion of protected sex ( mean difference , 0.35 ; P<.01 ) compared with similar adolescents in the health-promotion intervention . CONCLUSION Results provide evidence for the efficacy of HIV intervention in decreasing sexual activity and increasing condom use among Latino adolescents Background It is notoriously difficult to recruit patients to r and omised controlled trials in primary care . This is particularly true when the disease process under investigation occurs relatively infrequently and must be investigated during a brief time window . Bell 's palsy , an acute unilateral paralysis of the facial nerve is just such a relatively rare condition . In this case study we describe the organisational issues presented in setting up a large r and omised controlled trial of the management of Bell 's palsy across primary and secondary care in Scotl and and how we managed to successfully recruit and retain patients presenting in the community . Methods Where possible we used existing evidence on recruitment strategies to maximise recruitment and retention . We consider that the key issues in the success of this study were ; the fact that the research was seen as clinical ly important by the clinicians who had initial responsibility for recruitment ; employing an experienced trial co-ordinator and dedicated research ers willing to recruit participants seven days per week and to visit them at home at a time convenient to them , hence reducing missed patients and ensuring they were retained in the study ; national visibility and repeated publicity at a local level delivered by locally based principal investigators well known to their primary care community ; encouraging recruitment by payment to practice s and reducing the workload of the referring doctors by providing immediate access to specialist care ; good collaboration between primary and secondary care and basing local investigators in the otolarnygology trial centres Results Although the recruitment rate did not meet our initial expectations , enhanced retention meant that we exceeded our planned target of recruiting 550 patients within the planned time-scale . Conclusion While difficult , recruitment to and retention within multi-centre trials from primary care can be successfully achieved through the application of the best available evidence , establishing good relationships with practice s , minimising the workload of those involved in recruitment and offering enhanced care to all participants . Primary care trialists should describe their experiences of the methods used to persuade patients to participate in their trials when publishing their results STUDY OBJECTIVE For orthopaedic out patients judged as unlikely to require surgery , how does the cost-effectiveness of treatment from a musculo-skeletal medicine physician compare with that of a conventional orthopaedic surgeon-led service ? DESIGN Partially r and omised , pragmatic trial comparing management from a single musculo-skeletal medicine physician with orthopaedic surgeon-led management , with the timing and nature of treatments at the discretion of individual clinicians . Main outcomes were : change in patient reported health ( SF-36 and EuroQol ) , and marginal health service costs . SETTING Outpatient department of an Edinburgh orthopaedic hospital . SUBJECTS One thous and three hundred and twenty six people ; aged over 18 , referred to and later attending the outpatient department with a ' non-surgical ' musculo-skeletal condition , who provided baseline information . Eight hundred and twenty nine were r and omly allocated to management by either the musculo-skeletal medicine physician ( medical group ) or a conventional orthopaedic surgeon-led service ( surgical group ) ; 497 were assigned to the treatment groups according to their general practitioner 's preference . RESULTS There are aspects of the study design concerning statistical power , potential selection bias and generalisability , which mean that any results must be treated with caution . Although there was no statistically significant difference in health gain between the r and omly allocated groups ( with similar findings in the non-r and omised medical and surgical groups ) , the patient groups were heterogeneous and the confidence intervals did not rule out clinical ly important differences . The medical group received more outpatient treatment , 20 % vs. 10 % ( difference 95 % CI 5 % to 15 % ) with a higher rate of physiotherapy referral , 45 % vs. 30 % ( 15 % , 9 % to 22 % ) . The surgical group received more inpatient surgical care 6 % vs. 17 % ( -11 % , -15 % to -7 % ) . Mean healthcare costs in the medical group were 179 Pounds per patient compared with 287 Pounds in the surgical group ( -108 Pounds , -25 Pounds to -191 Pounds ) . CONCLUSIONS Interpretation should take into account the practical difficulties and circumstances of the study . Although no differences in health gain were found between these two management policies for ' non-surgical ' orthopaedic out patients , the trial was less statistically powerful than planned and the confidence intervals included clinical ly important differences . Differences in treatment emphasis gave estimated costs savings to the Health Service of 108 Pounds per patient treated by the musculo-skeletal 
    Output:
    
There was no good evidence that the addition of a non-monetary incentive , an offer of a non-monetary incentive , ' enhanced ' letters , letters delivered by priority post , additional reminders , or question naire question order either increased or decreased trial question naire response/retention .
There were few evaluations of ways to improve participants returning to trial sites for trial follow-up .
Monetary incentives and offers of monetary incentives increased postal and electronic question naire response .
Key results The methods that appeared to work were offering or giving a small amount of money for return of a completed question naire and enclosing a small amount of money with a question naire with the promise of a further small amount of money for return of a filled in question naire .