Identifying the participant characteristics that predict recruitment and retention of participants to randomised controlled trials involving children: a systematic review

Abstract

BackgroundRandomised controlled trials (RCTs) are recommended as the ‘gold standard’ in evaluating health care interventions. The conduct of RCTs is often impacted by difficulties surrounding recruitment and retention of participants in both adult and child populations. Factors influencing recruitment and retention of children to RCTs can be more complex than in adults. There is little synthesised evidence of what influences participation in research involving parents and children.AimTo identify predictors of recruitment and retention in RCTs involving children.MethodsA systematic review of RCTs was conducted to synthesise the available evidence. An electronic search strategy was applied to four databases and restricted to English language publications. Quantitative studies reporting participant predictors of recruitment and retention in RCTs involving children aged 0–12 were identified. Data was extracted and synthesised narratively. Quality assessment of articles was conducted using a structured tool developed from two existing quality evaluation checklists.ResultsTwenty-eight studies were included in the review. Of the 154 participant factors reported, 66 were found to be significant predictors of recruitment and retention in at least one study. These were classified as parent, child, family and neighbourhood characteristics. 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. When analysed according to setting and severity of the child’s illness there appeared to be little variation between groups. The quality of the studies varied. Articles adhered well to reporting guidelines around provision of a scientific rationale for the study and background information as well as displaying good internal consistency of results. However, few studies discussed the external validity of the results or provided recommendations for future research.ConclusionParent 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. Further studies that explore variables that can be influenced are warranted. Reporting of studies in this field need greater clarity as well as agreed definitions of what is meant by retention.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1415-0) contains supplementary material, which is available to authorized users.

Who can we reach and who can we keep? Predictors of intervention engagement and adherence in a cluster randomized controlled trial in South Africa

“…Our finding that intervention adherence and engagement was predicted by more years of schooling is consistent with previous research [2,13,34]. This is likely to be a function of the fact that individuals with higher levels of education have been primed to adhere and engage in intervention programmes, as exposure to more years of schooling is associated with healthy routines, structure, rules, and punctualityall factors assumed to be related to adherence.…”

“…That is, participants are more likely to drop out of community-based interventions if they are older. Gender and ethnicity have also been found to correlate with intervention retention, with evidence suggesting that in high-income countries, male participants from ethnic minorities are more likely to disengage from intervention programmes [1,13]. Similarly, lower levels of education has consistently been found to influence engagement and adherence, with participants with fewer years of schooling more likely to drop-out of intervention programmes [2,11,12].…”

“…To the best of our knowledge, only a handful of studies have explored the individual sociodemographic correlates of engagement and adherence [1,2,[11][12][13][14]. In their review of retention strategies employed in communitybased clinical trials, Davis et al [2] identified that engagement and adherence rates are negatively associated with participants' age.…”

Enrollment challenges in multicenter, international studies: The example of the GAS trial

“…Clinical trials are important for pediatric medicine as they provide high quality evidence. There is a perception that pediatric trials are difficult to perform due to a reluctance of families and physicians to participate . It is also thought that enrollment rates may vary between countries.…”

“…There is a perception that pediatric trials are difficult to perform due to a reluctance of families and physicians to participate. [3][4][5] It is also thought that enrollment rates may vary between countries. However, there are few studies that have tested these perceptions.…”