***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: Proper r and omisation means little if investigators can not include all r and omised participants in the primary analysis . Participants might ignore follow-up , leave town , or take aspartame when instructed to take aspirin . Exclusions before r and omisation do not bias the treatment comparison , but they can hurt generalisability . Eligibility criteria for a trial should be clear , specific , and applied before r and omisation . Readers should assess whether any of the criteria make the trial sample atypical or unrepresentative of the people in which they are interested . In principle , assessment of exclusions after r and omisation is simple : none are allowed . For the primary analysis , all participants enrolled should be included and analysed as part of the original group assigned ( an intent-to-treat analysis ) . In reality , however , losses frequently occur . Investigators should , therefore , commit adequate re sources to develop and implement procedures to maximise retention of participants . Moreover , research ers should provide clear , explicit information on the progress of all r and omised participants through the trial by use of , for instance , a trial profile . Investigators can also do secondary analyses on , for instance , per- protocol or as-treated participants . Such analyses should be described as secondary and non-r and omised comparisons . Mish and ling of exclusions causes serious method ological difficulties . Unfortunately , some explanations for mish and ling exclusions intuitively appeal to readers , disguising the seriousness of the issues . Creative mismanagement of exclusions can undermine trial validity Background Recruiting participants to r and omized controlled trials of health interventions can be very difficult . Internet-based recruitment is becoming an increasingly important mode of recruitment , yet there are few detailed accounts of experiences recruiting participants to mental health interventions . Objective To report on our experience with Internet-based recruitment to an online depression prevention intervention and pass on lessons we learned . Methods Participants were recruited to the Mood Memos study , an online preventive depression intervention , purely through Internet-based sources . The study was targeted to adults with subthreshold depression symptoms from several English-speaking countries . A variety of online recruitment sources were trialed , including search engine advertising ( Google , Yahoo ! , Bing ) , Facebook advertising , posts in forums and online noticeboards , and promotion through relevant websites and email newsletters of mental health organizations . Results The study website received visits from 94,808 individuals over the 14-month recruitment period . The recruitment target was reached with 1699 individuals signing up to the r and omized controlled trial and 1326 fully enrolling . Most visitors arrived via Google advertising , which promoted a depression-screening question naire . Google advertising accounted for nearly half of the total participants who signed up to the study , at an average cost of AUD $ 12 per participant . Promoting the study through trustworthy organizations and websites known to participants was also effective . Recruitment techniques that were less effective were contacting forums , email groups , and community noticeboards . Conclusions Several techniques , including Google advertising , were successful in recruiting participants to a trial evaluating an online depression intervention . Results suggest that Internet-based recruitment to mental health interventions is feasible and can be relatively affordable . Trial Registration Background Under-recruitment to r and omised controlled trials ( RCTs ) is often problematic and there may be particular difficulties in recruiting patients with severe mental illness . Aim To evaluate reasons for under-recruitment in an RCT of patients with severe mental illness Methods Qualitative study during the recruitment phase of an RCT of supported employment . Trial staff and recruiting clinicians were interviewed . Data were analyzed thematically using constant comparative techniques . Results Recruitment rates were low . Five main reasons for recruitment difficulties were found . These included : ( i ) misconceptions about trials , ( ii ) lack of equipoise , ( iii ) misunderst and ing of the trial arms , ( iv ) variable interpretations of eligibility criteria , ( v ) paternalism . Conclusion Reasons for recruitment difficulties in trials involving patients with severe mental illness include issues that occur in trials in general , but others are more specific to these patients . Clinician and patient involvement in the study design may improve recruitment in future similar trials Background Patient and public involvement in research ( PPIR ) may improve trial recruitment rates , but it is unclear how . Where trials use PPIR to improve design and conduct , many do not communicate this clearly to potential participants . Better communication of PPIR might encourage patient enrolment , as trials may be perceived as more socially valid , relevant and trustworthy . We aim ed to evaluate the impact on recruitment of directly advertising PPIR to potential trial participants . Methods This is a cluster trial , embedded within a host trial ( ‘ EQUIP ’ ) recruiting service users diagnosed with severe mental illness . The intervention was informed by a systematic review , a qualitative study , social comparison theory and a stakeholder workshop including service users and carers . Adopting Participatory Design approaches , we co- design ed the recruitment intervention with PPIR partners using a leaflet to advertise the PPIR in EQUIP and sent potential participants invitations with the leaflet ( intervention group ) or not ( control group ) . Primary outcome was the proportion of patients enrolled in EQUIP . Secondary outcomes included the proportions of patients who positively responded to the trial invitation . Results Thirty-four community mental health teams were r and omised and 8182 service users invited . For the primary outcome , 4 % of patients in the PPIR group were enrolled versus 5.3 % of the control group . The intervention was not effective for improving recruitment rates ( adjusted OR = 0.75 , 95 % CI = 0.53 to 1.07 , p = 0.113 ) . For the secondary outcome of positive response , the intervention was not effective , with 7.3 % of potential participants in the intervention group responding positively versus 7.9 % of the control group ( adjusted OR = 0.74 , 95 % CI = 0.53 to 1.04 , p = 0.082 ) . We did not find a positive impact of directly advertising PPIR on any other outcomes . Conclusion To our knowledge , this is the largest ever embedded trial to evaluate a recruitment or PPIR intervention . Advertising PPIR did not improve enrolment rates or any other outcome . It is possible that rather than advertising PPIR being the means to improve recruitment , PPIR may have an alternative impact on trials by making them more attractive , acceptable and patient-centred . We discuss potential reasons for our findings and implication s for recruitment practice and research .Trial registration numbersIS RCT N , IS RCT N16488358 . Registered on 14 May 2014 . Study Within A Trial , SWAT-26 . Registered on 21 January 2016 Background Patient underst and ing of study information is fundamental to gaining informed consent to take part in a r and omised controlled trial . In order to meet the requirements of research ethics committees , patient information material s can be long and need to communicate complex messages . There is concern that st and ard approaches to providing patient information may deter potential participants from taking part in trials . The Systematic Techniques for Assisting Recruitment to Trials ( MRC-START ) research programme aims to test interventions to improve trial recruitment . The aim of this study was to investigate the effect on recruitment of optimised patient information material s ( with improved readability and ease of comprehension ) compared with st and ard material s. The study was embedded within two primary care trials involving patients with long-term conditions . Methods The Healthlines Study involves two linked trials evaluating a telehealth intervention  in patients with depression ( Healthlines Depression ) or raised cardiovascular disease risk ( Healthlines CVD ) . We conducted two trials of a recruitment intervention , embedded within the Healthlines host trials . Patients identified as potentially eligible in each of the Healthlines trials were r and omised  to receive either the  original patient information material s or optimised versions of these material s. Primary outcomes were the proportion of participants r and omised ( Healthlines Depression ) and the proportion expressing interest in taking part ( Healthlines CVD ) . Results In Healthlines Depression ( n = 1364 ) , 6.3 % of patients receiving the optimised patient information material  s were r and omised into the study compared to 4.0 % in those receiving st and ard material s ( OR = 1.63 , 95 % CI = 1.00 to 2.67 ) . In Healthlines CVD ( n = 671 ) 24.0 % of those receiving optimised patient information material s responded positively to the invitation to participate , compared to 21.9 % in those receiving st and ard material s ( OR = 1.12 , 95 % CI = 0.78 to 1.61 ) . Conclusions Evidence from these two embedded trials suggests limited benefits of optimised patient information material s on recruitment rates , which may only be apparent in some patient population s , with no effects on other outcomes . Further embedded trials are needed to provide a more precise estimate of effect , and to explore further how effects vary by trial context , intervention , and patient population .Trial registration Current Controlled Trials : Healthlines Depression ( IS RCT N27508731 ) on 26 June 2012 ; and Healthlines CVD ( IS RCT N14172341 ) on 5 July Background Mindfulness interventions to reduce psychological distress are well-suited to pregnancy , due to their brief and non-pharmacological nature , but there is a need for more robust evidence determining their usefulness . This pilot study was design ed to explore the feasibility of a r and omised controlled trial of a mindfulness intervention to reduce antenatal depression , anxiety and stress . Methods The study was design ed in two parts 1 ) a non-r and omised trial targeting women at risk of mental health problems ( a selected population ) and 2 ) a r and omised controlled trial ( RCT ) of a universal population . Process evaluation focused on feasibility of recruitment pathways , participant retention , acceptability of study measures , and engagement with mindfulness practice s. Measurement of psychological distress was taken pre and post intervention through the Centre for Epidemiologic Studies Depression Scale Revised , the Depression Anxiety and Stress Scale-21 , the State-Trait Anxiety Inventory , and the Perceived Stress Scale . Results 20 women were recruited to the non-r and omised trial , and 32 to the RCT . Recruitment through a mailed study brochure at the time of booking-in to the hospital result ed in the largest number of participants in the RCT ( 16/32 ; 50 % ) , and result ed in considerably earlier recruitment ( 50 % in first trimester , 50 % second trimester ) compared to recruitment through the antenatal clinic waiting room ( 86 % in second trimester , 14 % third trimester ) . Over a third of women in the universal population scored above clinical cut-offs for depression and anxiety , indicating a sample with more symptomology than the general population . The most common reason for loss to follow-up was delivery of baby prior to follow-up ( n = 9 ) . In the non-r and omised study , significant within group improvements to depression and anxiety were observed . In the intervention arm of the RCT there were significant within group improvements to anxiety and mindfulness . No between group differences for the intervention and ` care as usual ’ control group were observed . Conclusions This small pilot study provides evidence on the feasibility of an antenatal mindfulness intervention to reduce psychological distress . Major challenges include : finding ways to facilitate recruitment in early pregnancy and engaging younger women and other vulnerable population s . Trial registration Australian New Zeal and Clinical Trials Registry ACTRN12613000742774 ( 31/10/2012 ) OBJECTIVE Our aim was to analyze monetary incentives and shortening the question naire as means of increasing response rates in a mailed follow-up survey 1 year after inpatient psychotherapeutic treatment . Additionally , effects on partial nonresponse and the assessment of treatment outcome were examined . STUDY DESIGN AND SETTING In a 2x2 factorial design , a sample of 3,825 patients was r and omized to the two following interventions : ( 1 ) receiving a prepaid monetary incentive or none ; and ( 2 ) getting a short or a long question naire . Treatment outcome was measured prospect ively by a self- assessment instrument for psychopathology . RESULTS When using incentives , the response rate significantly increased by 7.3 % ( 95 % confidence interval [ CI ] 2.6 - 11.9 % ) . Receiving a short question naire led to an augmentation of the response rate of 3.7 % ( 95 % CI 0.9 - 8.3 % ) , which was not significant . The corresponding odds ratios were significantly increased for monetary incentives ( 1.36 ; 95 % CI 1.30 - 1.88 ) , and when abridging the question naire ( 1.15 ; 95 % CI 1.01 - 1.31 ) . However , partial nonresponse and treatment outcome were independent of the two factors . CONCLUSION Incentives and a shorter question naire led to higher return rates but did not affect partial nonresponse and self-report of treatment outcome in a r and omized postal survey Limitations of printed , text-based , consent forms have long been documented and may be particularly problematic for persons at risk for impaired decision-making capacity , such as those with schizophrenia . We conducted a r and omized controlled comparison of the effectiveness of a multimedia vs routine consent procedure ( augmented with a 10-minute control video presentation ) as a means of enhancing comprehension among 128 middle-aged and older persons with schizophrenia and 60 healthy comparison subjects . The primary outcome measure was manifest decisional capacity ( underst and ing , appreciation , reasoning , and expression of choice ) for participation in a ( hypothetical ) clinical drug trial , as measured with the MacArthur Competence Assessment Tool for Clinical Research ( MacCAT-CR ) and the University of California San Diego ( UCSD ) Brief Assessment for Capacity to Consent ( UBACC ) . The MacCAT-CR and UB 
    Output:
    
Retrospective comparisons of recruitment methods showed that non-web-based advertisement and recruitment by clinical research staff each have advantages in efficiency .
Financial incentives , abridged question naires and pre-notification had a positive effect on retention rates .
The recruitment studies included showed differences in strategies , clinical setting s , mental health conditions and study design .
It is difficult to assess the overall effectiveness of any particular recruitment strategy as some strategies that worked well for a particular population may not work as well for others .
Paying attention to the accessibility of information and consent material s may help improve recruitment .