***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: Background A commonly reported problem with the conduct of multicentre r and omised controlled trials ( RCTs ) is that recruitment is often slower or more difficult than expected , with many trials failing to reach their planned sample size within the timescale and funding originally envisaged . The aim of this study was to explore factors that may have been associated with good and poor recruitment in a cohort of multicentre trials funded by two public bodies : the UK Medical Research Council ( MRC ) and the Health Technology Assessment ( HTA ) Programme . Methods The cohort of trials was identified from the administrative data bases held by the two funding bodies . 114 trials that recruited participants between 1994 and 2002 met the inclusion criteria . The full scientific applications and subsequent trial reports su bmi tted by the trial teams to the funders provided the principal data sources . Associations between trial characteristics and recruitment success were tested using the Chi-squared test , or Fisher 's exact test where appropriate . Results Less than a third ( 31 % ) of the trials achieved their original recruitment target and half ( 53 % ) were awarded an extension . The proportion achieving targets did not appear to improve over time . The overall start to recruitment was delayed in 47 ( 41 % ) trials and early recruitment problems were identified in 77 ( 63 % ) trials . The inter-relationship between trial features and recruitment success was complex . A variety of strategies were employed to try to increase recruitment , but their success could not be assessed . Conclusion Recruitment problems are complex and challenging . Many of the trials in the cohort experienced recruitment difficulties . Trials often required extended recruitment periods ( sometimes supported by additional funds ) . While this is of continuing concern , success in addressing the trial question may be more important than recruitment alone This paper reports findings on parental engagement in a community-based parent training intervention . As part of a r and omized trial , 821 parents were offered group-based Triple P as a parenting skills prevention program . Program implementation was conducted by practitioners . The intervention was implemented between Waves 1 and 2 of a longitudinal study , with a participation rate of 69 % and a retention rate of 96 % . The study finds that a practitioner-led dissemination can achieve recruitment and completion rates that are similar to those reported in research er-led trials . Second , the study found that different factors are associated with the various stages of the parental engagement process . Family-related organizational and timing obstacles to participation primarily influence the initial stages of parental involvement . The strength of neighborhood networks plays a considerable role at the participation and completion stages of parental engagement . The general course climate and the intensity of program exposure predict the utilization of the program several months after the delivery Background As the number of r and omised controlled trials of medicines for children increases , it becomes progressively more important to underst and the experiences of parents who are asked to enrol their child in a trial . This paper presents a narrative review of research evidence on parents ' experiences of trial recruitment focussing on qualitative research , which allows them to articulate their views in their own words . Discussion Parents want to do their best for their children , and socially and legally their role is to care for and protect them yet the complexities of the medical and research context can challenge their fulfilment of this role . Parents are simultaneously responsible for their child and cherish this role yet they are dependent on others when their child becomes sick . They are keen to exercise responsibility for deciding to enter a child in a trial yet can be fearful of making the ' wrong ' decision . They make judgements about the threat of the child 's condition as well as the risks of the trial yet their interpretations often differ from those of medical and research experts . Individual parents will experience these and other complexities to a greater or lesser degree depending on their personal experiences and values , the medical situation of their child and the nature of the trial . Interactions at the time of trial recruitment offer scope for negotiating these complexities if practitioners have the flexibility to tailor discussion s to the needs and situation of individual parents . In this way , parents may be helped to retain a sense that they have acted as good parents to their child whatever decision they make . Summary Discussing r and omised controlled trials and gaining and providing informed consent is challenging . The unique position of parents in giving proxy consent for their child adds to this challenge . Recognition of the complexities parents face in making decisions about trials suggests lines for future research on the conduct of trials , and ultimately , may help improve the experience of trial recruitment for all parties PURPOSE Loss of participants in r and omized clinical trials threatens the validity of study findings . The purpose of this study was to determine pre-r and omization predictors of study completion status throughout the course of a r and omized clinical trial involving young children with type 1 diabetes and their primary caregivers . METHODS An intervention to improve adherence to the diabetes treatment regimen was delivered as part of the child 's regular 3-month diabetes clinic visit . The study protocol involved 7 clinic visits across 18 months for the Immediate Treatment group and 9 clinic visits across 24 months for the Delayed Treatment group . Among those who completed the study and regardless of treatment group , participants were categorized into two groups : On-Time Completers ( n=41 ) and Late Completers ( n=39 ) . Demographic , disease , and psychosocial characteristics of children and their primary caregivers measured prior to study r and omization were tested for their association with the participants ' completion status ( i.e. , On-Time Completers , Late Completers , or Withdrawals ) . RESULTS Of the 108 participants , 28 ( 25.9 % ) withdrew and 80 ( 74.1 % ) completed the study .  On-Time Completers ( i.e. , study completed within 4 months of expected date ) were more likely to have private insurance and primary caregivers with some college education . Late Completers ( i.e. , study completion took longer than 4 months ) were more likely to be boys and to have primary caregivers who reported mild to moderate levels of depression . Children who subsequently withdrew from the study reported poorer diabetes-related quality of life and poorer school-related quality of life at study inception and were more likely to have primary caregivers who did not work outside the home . CONCLUSIONS Pre-r and omization screening of participants on both demographic and psychological variables may help identify those at greatest risk for study withdrawal or poor study protocol adherence , permitting the investigators to develop retention strategies aim ed at this high-risk group Background Despite important implication s for the budgets , statistical power and generalisability of research findings , detailed reports of recruitment and retention in r and omised controlled trials ( RCTs ) are rare . The NOURISH RCT evaluated a community-based intervention for first-time mothers  that promoted protective infant feeding practice s as a primary prevention strategy for childhood obesity . The aim of this paper is to provide a detailed description and evaluation of the recruitment and retention strategies used . Methods A two stage recruitment process design ed to provide a consecutive sampling framework was used . First- time mothers delivering healthy term infants were initially approached in postnatal wards of the major maternity services in two Australian cities for consent to later contact ( Stage 1 ) . When infants were approximately four months old mothers were re-contacted by mail for enrolment ( Stage 2 ) , baseline measurements ( Time 1 ) and subsequent r and om allocation to the intervention or control condition . Outcomes were assessed at infant ages 14 months ( Time 2 ) and 24 months ( Time 3 ) . Results At Stage 1 , 86 % of eligible mothers were approached and of these women , 76 % consented to later contact . At Stage 2 , 3 % had become ineligible and 76 % could be recontacted . Of the latter , 44 % consented to full enrolment and were allocated . This represented 21 % of mothers screened as eligible at Stage 1 . Retention at Time 3 was 78 % . Mothers who did not consent or discontinued the study were younger and less likely to have a university education  . Conclusions The consent and retention rates of our sample of first time mothers are comparable with or better than other similar studies . The recruitment strategy used allowed for detailed information from non-consenters to be collected ; thus selection bias could be estimated . Recommendations for future studies include being able to contact participants via mobile phone ( particularly text messaging ) , offering home visits to reduce participant burden and considering the use of financial incentives to support participant retention . Trial registration Australian and New Zeal and Clinical Trials Registry Number The hierarchy of evidence in assessing the effectiveness of interventions or treatments is explained , and the gold st and ard for evaluating the effectiveness of interventions , the r and omised controlled trial , is discussed . Issues that need to be considered during the critical appraisal of r and omised controlled trials , such as assessing the validity of trial methodology and the magnitude and precision of the treatment effect , and deciding on the applicability of research results , are discussed . Important terminologies such as r and omisation , allocation concealment , blinding , intention to treat , p values , and confidence intervals are explained OBJECTIVES To operationalize a comprehensive description of attrition , including pre- inclusion , dropout , and attrition due to intermittent missing data , and to test a predictive model of attrition using a data set from a r and omized controlled intervention in pediatric asthma . METHODS Participants included children , ages 4 - 12 , diagnosed with asthma and their caregivers .  Demographic variables and outcome measures of asthma morbidity were examined in 327 families to determine their association with attrition . RESULTS Families who did not complete r and omization and the intervention tended to have younger caregivers than did completers . Caregiver age emerged as the most consistent predictor of pre- inclusion and dropout attrition . There were no significant predictors of attrition due to intermittent missing data . CONCLUSION Younger caregivers may be at particular risk for attrition in pediatric asthma intervention studies and warrant special attention by investigators OBJECTIVE To examine attrition variables in r and omized controlled trials of cognitive behavioral interventions for children with chronic illnesses . METHODS We examined attrition rates reported on 40 r and omized cognitive behavioral interventions published in six pediatric research journals , during the years 2002 - 2007 . Intervention focus was limited to children with a chronic medical condition , such as asthma , obesity , arthritis , diabetes , cancer , sickle cell disease , and cystic fibrosis . RESULTS Mean rate of enrollment refusal was 37 % ( range 0 - 75 % ) . Mean attrition rate was 20 % ( range 0 - 54 % ) for initial follow-up and 32 % ( range 0 - 59 % ) for extended follow-up . Of the review ed articles , 40 % included a CONSORT diagram . CONCLUSIONS Strategies that can be used to limit attrition include tailoring recruitment to the study population , providing personalized feedback , maintaining consistent study procedures , providing incentives , and using intensive tracking measures . There is a need for st and ardized definitions and reporting of attrition rates in r and omized cognitive behavioral intervention studies OBJECTIVES Survival rates for childhood cancer have improved substantially partly as a result of national and international r and omized clinical trials ( RCT ) . However , the decision for families is complex and emotional . Our aim was to describe the views of mothers of children newly diagnosed with ALL regarding consent to r and omized controlled trials . DESIGN Qualitative interview to explore mothers knowledge , and reasons for involving their child in RCTs . Interviews took place in mothers ' homes . PARTICIPANTS Fifty mothers of children with newly diagnosed ALL ( age 4 - 16 years ; mean = 7.4 ) recruited through research nurses at outpatient appointments . RESULTS All but three families had consented for their child to be treated in the RCT , although there was wide variation in their underst and ing of the aims , costs and benefits . Most mothers reported the aim of the trial to compare ' old ' and ' new ' treatments . CONCLUSION Despite detailed verbal and written information , mothers were poorly informed about the purpose of the trial , and possibility of side effects . Individual preferences for either st and ard or new treatment were routinely reported . The data raise questions about the extent to which families give truly informed consent to recruitment of their child to an RCT A significant percentage of children with disruptive behavior disorders do not receive mental health assistance . Utilization is lowest among groups whose children are at greatest risk . To increase the availability , accessibility , and cost efficacy of parent training programs , this prospect i ve r and omized trial compared a large group community-based parent training program to a clinic-based individual parent training ( PT ) programs .  All families of junior kindergartners in the Hamilton public and separate school boards were sent a checklist regarding problems at home . Those returning question naires above the 90th percentile were block r and omly assigned to : ( 1 ) a 12-week clinic-based individual parent training ( Clinic/Individual ) , ( 2 ) a 12-week community-based large group parent training ( Community/Group ) , or ( 3 ) a waiting list control condition .  Immigrant families , those using English as a second language , and parents of children with severe behaviour problems were significantly more likely to enroll in Community/Groups than Clinic/Individual PT . Parents in Community/Groups reported greater improvements in behaviour problems at home and better maintenance of these gains at 6-month follow-up . A cost analysis showed that , with groups of 18 families , Community/Groups are more than six times as cost effective as Clinic/Individual programs Women with inadequate prenatal care were recruited to a multi-component  parenting intervention study . Because it was anticipated that this high-risk population might present challenges to retention , a variety of strategies were employed to maintain their participation in the study . This report review s the results of these retention efforts and compares the population that completed the study versus those that terminated prior to study completion . Two hundred and eighty-six women were r and omized to an intervention or control group . Careful tracking of the mothers , offering incentives for completing various study activities and providing a culturally competent staff were among the strategies employed to maintain participation . Comparison 
    Output:
    
Parent characteristics ( e.g. ethnicity , age , education , socioeconomic status ( SES ) ) were the most commonly reported predictors of participation for both recruitment and retention .
Being young , less educated , of an ethnic minority and having low SES appear to be barriers to participation in RCTs although there was little agreement between studies .
Conclusion Parent characteristics may predict participation of children and their families to RCTs ; however , there was a lack of consensus .
Whilst sociodemographic variables may be useful in identifying which groups are least likely to participate they do not provide insight into the processes and barriers to participation for children and families .