Characteristics and practices of school-based cluster randomised controlled trials for improving health outcomes in pupils in the United Kingdom: a methodological systematic review

Findings from a cluster randomised feasibility study of a school-based physical activity role model intervention (CHARMING) for 9-10-year-old girls

BACKGROUND

Girls' physical activity levels decline to a greater extent than boys as they enter adolescence. Role model interventions offer a potential solution to combat this public health issue. This study reports findings of a feasibility study of the CHARMING (CHoosing Active Role Models to INspire Girls) programme, a 6-week after-school primary school-based, community linked, role-model intervention.

METHODS

Between January 2021 and August 2022, a feasibility cluster randomised controlled trial (cRCT), with process and health economic evaluations was conducted in South Wales. Secondary schools were recruited, along with their adjoining primary schools to recruit Year 5 girls (aged 9-10 years). Role models were recruited from the surrounding school community (community role models) and from each secondary school (peer role models). A survey of self-reported outcome measures and accelerometers were administered at baseline and at 12 months. Following baseline, six primary schools were randomly allocated to intervention or control (usual practice) on a 2:1 basis. Post-intervention delivery, observations (n = 30), focus groups (n = 13) and interviews (n = 22) were conducted to explore study and intervention acceptability, feasibility and fidelity. Five pre-specified progression criteria included: implementation, attendance rates, and acceptability of the intervention, as well as completion of the primary outcome, including levels of completeness.

RESULTS

One hundred and fifty-six girls from six primary schools (four intervention and two control) were eligible to take part. Of these, 96 (62%) and 97 (62%) Year 5 girls took part in the survey and accelerometer measures respectively, with 78 (81%) and 77 (79%) participating in the 12-month follow-up. Findings indicate that it is feasible to collect health-related quality of life information from 9- to 10-year-olds using a digital self-report survey completed in schools. Despite the impacts of the COVID-19 pandemic, three of the five criteria (implementation, acceptability and completion of primary outcome) for progressing to a full-scale evaluation were met. Process evaluation data provide understandings of why two criteria (attendance and completeness of the primary outcome) were not met. Overall, data suggest that acceptability and feasibility of the intervention were high, and that the intervention was broadly delivered as intended. Alterations to the study measures and the intervention were suggested to increase intervention acceptability and feasibility, including recruitment and retention and extending the length of delivery in line with original intentions (12 weeks).

CONCLUSIONS

Findings suggest the CHARMING intervention and cRCT design are likely to be acceptable and feasible, subject to further intervention and evaluation design optimisation.

TRIAL REGISTRATION

ClinicalTrials.gov ISRCTN36223327. Registered March 29, 2021.

Exploring the Effects of a School Mindfulness-Based Intervention in French Primary Public Schools-A Pilot Study

Background/Objectives: School-Mindfulness-Based Interventions (SMBIs) have shown positive effects on children's mental health by enhancing emotional regulation and present-moment awareness. This pilot study explored the effects of an SMBI program on anxiety, depression, mindfulness, emotional awareness, executive functioning, and school well-being among French primary school students (mean age = 116 months; SD = 9.06). Methods: A quasi-experimental longitudinal design was employed, with assessments at pre-intervention (T1), post-intervention (T2), and follow-up (T3). Data were analyzed using repeated-measures ANOVA. Results: The study found no statistically significant changes across all assessed dimensions. The lack of significant results may reflect factors such as the program's duration, small sample size, reliance on self-report measures, and contextual challenges like the COVID-19 pandemic. However, slight numerical trends in anxiety and mindfulness scores suggest potential benefits that larger studies may better detect. Conclusions: While no significant improvements were observed, the findings highlight important considerations for SMBI implementation in schools in France and internationally. Future research should address current limitations by increasing sample sizes, employing multi-informant assessments, and integrating SMBIs with complementary approaches, such as social-emotional learning. Extending the program duration or incorporating booster sessions may enhance effectiveness. Embedding SMBIs into school curricula through a whole-school approach could foster the sustainable and impactful integration of mindfulness practices into daily school life.

A school-based intervention to improve mental health outcomes for children with cerebral visual impairment (CVI): feasibility cluster randomised trial

BACKGROUND

Cerebral visual impairment (CVI) refers to brain-related vision difficulties, which are often undiagnosed and may lead to poor mental health outcomes. We have developed an intervention to improve mental health outcomes for affected children, and it requires evaluation. The aim of this study was to assess the feasibility of methods proposed for a future definitive cluster randomised trial.

METHODS

This 18-month study took place in South West England, UK, between 2019 and 2021 including a 6-month pause due to the COVID pandemic. Participants were children aged 7-10 years in mainstream primary schools and their teachers and parents. We recruited head teachers on behalf of their school. The intervention was a resource pack for teachers explaining about CVI, providing universal and targeted strategies to help children with CVI and the offer of CVI assessments at the local eye clinic. The control schools continued with usual practice. Our objectives were to evaluate the feasibility of recruitment and data collection, attrition, acceptability of the study methods and implementation of the intervention. We conducted a process evaluation including interviews and questionnaires.

RESULTS

We sent invitation letters to 297 schools, received responses to 6% and recruited 40% of these (7 schools, 1015 children). Parents of 36/1015 (3.5%) children opted out. Baseline data were collected from teachers for 94% children, and 91% children completed self-report questionnaires; parent-report questionnaires were returned for 19% of children. During the exceptional circumstance of the COVID pandemic, two schools left the study, and many children were not attending school, meaning follow-up data were received from 32% of children, 16% of teachers and 14% of parents. Interview data indicated that the intervention was acceptable, and teachers would have preferred on-site eye tests to the offer of a clinic appointment and a clear timetable for study events. Teachers in intervention schools reported expected changes in the children's and their own behaviour. There was some contamination between study arms.

CONCLUSIONS

A full-scale trial would be feasible, enhanced by insights from this feasibility trial, in non-pandemic times. Sharing these data with teachers, education policymakers and parents is planned to refine the design.

TRIAL REGISTRATION

ISRCTN13762177.

Moderators of cognitive and behaviour therapies for prevention and treatment of anxiety disorders in children and adolescents: A systematic review and meta-analysis

Previous studies have indicated wide variation in the effectiveness of cognitive and behaviour therapies (CBTs) for preventing and treating anxiety disorders in children and adolescents, indicating the presence of moderators influencing outcomes. This meta-analysis investigated whether sample characteristics (child age, child baseline anxiety levels, parental baseline anxiety levels) and intervention characteristics (intervention duration, facilitator contact time, facilitator background, delivery formats, parental involvement) moderate the effectiveness of CBTs for universal prevention, targeted prevention, and treatment of anxiety disorders in children and adolescents. We identified 86 eligible randomized controlled trials (RCTs) assessing the effectiveness of 98 CBTs versus non-active controls. Effect sizes were the post-intervention standardized mean difference of children's broad anxiety symptoms between CBT and non-active controls. Moderation analyses were conducted separately on child- and parent-reported outcomes using meta-regression and subgroup analyses. We found some evidence for (1) a moderating role of child age, facilitator background, and parental involvement on the effectiveness of CBTs for universal prevention; (2) a moderating role of child age and intervention duration on the effectiveness of CBTs for targeted prevention; (3) a moderating role of child age, facilitator contact time, and delivery formats on the effectiveness of CBTs for treatment. There was no evidence for a moderating role of child baseline anxiety levels on the effectiveness of CBTs for universal/targeted prevention or treatment. The moderating role of parental baseline anxiety levels and its potential interaction with parental involvement was not tested given the limited available data. Although these findings provide insights into the question of what works for whom, they should be interpreted cautiously given the limited available data, wide variation in outcomes, potential confounders, and discrepancies between child- and parent-reported outcomes.

Guidelines for the content of statistical analysis plans in clinical trials: protocol for an extension to cluster randomized trials

BACKGROUND

Guidance exists to inform the content of statistical analysis plans in clinical trials. Though not explicitly stated, this guidance is generally focused on clinical trials in which the randomization units are individual patients and not groups of patients. There are critical considerations for the analysis of cluster randomized trials, such as accounting for clustering, the risk of imbalances between the arms due to post-randomization recruitment, and the need to use small sample corrections when the number of clusters is small.

METHODS

This paper outlines the protocol for the development of a set of reporting guidelines for the content of statistical analysis plans for cluster randomized trials (including variations such as the stepped wedge cluster randomized trial and other cluster cross-over designs) by extending the minimum reporting analysis requirements as previously defined for individually randomized trials to cluster randomized trials. The guideline will be developed using a consensus-based approach, modifying existing reporting items from the guideline for individually randomized trials and extending to include new items.

DISCUSSION

The guideline will be developed so it can be used independently of the guideline for individually randomized designs. The consensus guidelines will be published in an open-access journal, including key guidance as well as exploration and elaboration.

Uncovering individualised treatment effects for educational trials

Large-scale Randomised Controlled Trials (RCTs) are widely regarded as "the gold standard" for testing the causal effects of school-based interventions. RCTs typically present the statistical significance of the average treatment effect (ATE), which captures the effect an intervention has had on average for a given population. However, key decisions in child health and education are often about individuals who may be very different from those averages. One way to identify heterogeneous treatment effects across different individuals, not captured by the ATE, is to conduct subgroup analyses. For example, free school meal (FSM) pupils as required for projects funded by the Education Endowment Foundation (EEF) in England. These subgroup analyses, as we demonstrate in 48 EEF-funded RCTs involving over 200,000 students, are usually not standardised across studies and offer flexible degrees of freedom to researchers, potentially leading to mixed, if not misleading, results. Here, we develop and deploy an alternative to ATE and subgroup analysis, a machine-learning and regression-based framework to predict individualised treatment effects (ITEs). ITEs could show where an intervention worked, for which individuals, and to what extent. Our findings have implications for decision-makers in fields like education, healthcare, law, and clinical practices concerning children and adolescents.

School-level intra-cluster correlation coefficients and autocorrelations for children's accelerometer-measured physical activity in England by age and gender

BACKGROUND

Randomised, cluster-based study designs in schools are commonly used to evaluate children's physical activity interventions. Sample size estimation relies on accurate estimation of the intra-cluster correlation coefficient (ICC), but published estimates, especially using accelerometry-measured physical activity, are few and vary depending on physical activity outcome and participant age. Less commonly-used cluster-based designs, such as stepped wedge designs, also need to account for correlations over time, e.g. cluster autocorrelation (CAC) and individual autocorrelation (IAC), but no estimates are currently available. This paper estimates the school-level ICC, CAC and IAC for England children's accelerometer-measured physical activity outcomes by age group and gender, to inform the design of future school-based cluster trials.

METHODS

Data were pooled from seven large English datasets of accelerometer-measured physical activity data between 2002-18 (> 13,500 pupils, 540 primary and secondary schools). Linear mixed effect models estimated ICCs for weekday and whole week for minutes spent in moderate-to-vigorous physical activity (MVPA) and being sedentary for different age groups, stratified by gender. The CAC (1,252 schools) and IAC (34,923 pupils) were estimated by length of follow-up from pooled longitudinal data.

RESULTS

School-level ICCs for weekday MVPA were higher in primary schools (from 0.07 (95% CI: 0.05, 0.10) to 0.08 (95% CI: 0.06, 0.11)) compared to secondary (from 0.04 (95% CI: 0.03, 0.07) to (95% CI: 0.04, 0.10)). Girls' ICCs were similar for primary and secondary schools, but boys' were lower in secondary. For all ages, combined the CAC was 0.60 (95% CI: 0.44-0.72), and the IAC was 0.46 (95% CI: 0.42-0.49), irrespective of follow-up time. Estimates were higher for MVPA vs sedentary time, and for weekdays vs the whole week.

CONCLUSIONS

Adequately powered studies are important to evidence effective physical activity strategies. Our estimates of the ICC, CAC and IAC may be used to plan future school-based physical activity evaluations and were fairly consistent across a range of ages and settings, suggesting that results may be applied to other high income countries with similar school physical activity provision. It is important to use estimates appropriate to the study design, and that match the intended study population as closely as possible.

Participation in organised sport to improve and prevent adverse developmental trajectories of at-risk youth: A systematic review

Background

Healthy after-school activities such as participation in organised sport have been shown to serve as important resources for reducing school failure and other problem/high-risk behaviour. It remains to be established to what extent organised sport participation has positive impacts on young people in unstable life circumstances.

Objectives

What are the effects of organised sport on risk behaviour, personal, emotional and social skills of young people, who either have experienced or are at-risk of experiencing an adverse outcome?

Search Methods

The database searches were carried out in March 2023 and other sources were searched in May 2023. We searched to identify both published and unpublished literature.

Selection Criteria

The intervention was participation in leisure time organised sport. Young people between 6 and 18 years of age, who either have experienced or are at-risk of experiencing an adverse outcome were eligible. Primary outcomes were problem/high-risk behaviour and a secondary outcomes social and emotional outcomes. Studies that used a control group were eligible for. Studies that utilised qualitative approaches were not.

Data Collection and Analysis

The number of potentially relevant studies was 43,716. Thirteen studies met the inclusion criteria. Only seven studies could be used in the data synthesis. Five studies were judged to have a critical risk of bias and were excluded from the meta-analysis. One study did not report data that enabled the calculation of effect sizes and standard errors. Meta-analyses were conducted on each conceptual outcome separately. All analyses were inverse variance weighted using random effects statistical models.

Main Results

Two studies were from Canada, one from Australia, and the remaining from the USA. The timespan of the interventions was 23 years, from 1995 to 2018. The median number of participants analysed was 316, and the median number of controls was 452. A number of primary outcomes were reported but each in a single study only. Concerning secondary outcomes, two studies reported the effect on overall psychosocial adjustment at post-intervention. The standardised mean difference was 0.70 (95% CI 0.28-1.11). There was a small amount of heterogeneity. Three studies reported on depressive symptoms at 0-3 years follow-up. The standardised mean difference was 0.02 (95% CI -0.01 to 0.06). There was no heterogeneity between the three studies. In addition, a number of other secondary outcomes were reported each in a single study only.

Authors' Conclusions

There were too few studies included in the meta-analyses in order for us to draw any conclusion. The dominance of Northern America clearly limiting the generalisability of the findings. The majority of the studies were not considered to be of overall high quality and the process of excluding studies with critical risk of bias from the meta-analysis applied in this review left us with only 7 of a total of 13 possible studies to synthesise. Further, because too few studies reported results on the same type of outcome, at most three studies could be combined in a particular meta-analysis and no meta-analysis could be performed on any of the primary outcomes.

Key considerations for designing, conducting and analysing a cluster randomized trial

Not only do cluster randomized trials require a larger sample size than individually randomized trials, they also face many additional complexities. The potential for contamination is the most commonly used justification for using cluster randomization, but the risk of contamination should be carefully weighed against the more serious problem of questionable scientific validity in settings with post-randomization identification or recruitment of participants unblinded to the treatment allocation. In this paper we provide some simple guidelines to help researchers conduct cluster trials in a way that minimizes potential biases and maximizes statistical efficiency. The overarching theme of this guidance is that methods that apply to individually randomized trials rarely apply to cluster randomized trials. We recommend that cluster randomization be only used when necessary-balancing the benefits of cluster randomization with its increased risks of bias and increased sample size. Researchers should also randomize at the lowest possible level-balancing the risks of contamination with ensuring an adequate number of randomization units-as well as exploring other options for statistically efficient designs. Clustering should always be allowed for in the sample size calculation; and the use of restricted randomization (and adjustment in the analysis for covariates used in the randomization) should be considered. Where possible, participants should be recruited before randomizing clusters and, when recruiting (or identifying) participants post-randomization, recruiters should be masked to the allocation. In the analysis, the target of inference should align with the research question, and adjustment for clustering and small sample corrections should be used when the trial includes less than about 40 clusters.

Intracluster correlation coefficients from school-based cluster randomized trials of interventions for improving health outcomes in pupils

BACKGROUND AND OBJECTIVES

To summarize intracluster correlation coefficient (ICC) estimates for pupil health outcomes from school-based cluster randomized trials (CRTs) across world regions and describe their relationship with study design characteristics and context.

METHODS

School-based CRTs reporting ICCs for pupil health outcomes were identified through a literature search of MEDLINE (via Ovid). ICC estimates were summarized both overall and for different categories of study characteristics.

RESULTS

Two hundred and forty-six articles reporting ICC estimates were identified. The median (interquartile range) ICC was 0.031 (0.011 to 0.08) at the school level (N = 210) and 0.063 (0.024 to 0.1) at the class level (N = 46). The distribution of ICCs at the school level was well described by the beta and exponential distributions. Besides larger ICCs in definitive trials than feasibility studies, there were no clear associations between study characteristics and ICC estimates.

CONCLUSION

The distribution of school-level ICCs worldwide was similar to previous summaries from studies in the United States. The description of the distribution of ICCs will help to inform sample size calculations and assess their sensitivity when designing future school-based CRTs of health interventions.

Assessing the Feasibility of a Peer Education Project to Improve Mental Health Literacy in Adolescents in the UK

Many mental health problems begin in adolescence and occur on a spectrum of severity: early recognition and intervention is important. This study is a quantitative feasibility study of the Mental Health Foundation's Peer Education Project (PEP). Attrition, psychometric properties of questionnaires, indications of improvement on a range of outcomes, and sample size required for a powered trial of effectiveness were assessed. 203 students completed the survey both pre and post-intervention. It was found that existing previously-validated measures had good psychometric properties, with two new questionnaires demonstrating reasonable reliability (self-help confidence alpha = 0.78, mental health knowledge alpha = 0.59). There were indications of improvement in help-seeking intentions, the number of sources likely to seek help from, and mental health knowledge from pre- to post-intervention. A future trial of PEP with a sample of approximately 36 schools, researcher-led data collections, and help-seeking intentions or sources as a primary outcome appears to be feasible.

Identifying Child Anxiety Through Schools-identification to intervention (iCATS-i2i): protocol for a cluster randomised controlled trial to compare screening, feedback and intervention for child anxiety problems to usual school practice

BACKGROUND

Systematically screening for child anxiety problems, and offering and delivering a brief, evidence-based intervention for children who are identified as likely to benefit would minimise common barriers that families experience in accessing treatment. We have developed a short parent-report child anxiety screening questionnaire, and procedures for administering screening questionnaires, sharing screening outcomes with families, and offering and delivering a brief parent-led online intervention (OSI: Online Support and Intervention for child anxiety) through schools. This trial aims to evaluate clinical and health economic outcomes for (1) children (aged 8-9) who screen positive for anxiety problems at baseline (target population) and (2) the wider population of all children in participating classes (total population) in schools randomly allocated to receive identification-to-intervention procedures and usual school practice ('screening and intervention'), compared to assessment and usual school practice only ('usual school practice').  METHODS: The trial design is a parallel-group, superiority cluster randomised controlled trial, with schools (clusters) randomised to 'screening and intervention' or 'usual school practice' arms in a 1:1 ratio stratified according to the level of deprivation within the school. We will recruit schools and participants in two phases (a pilot phase (Phase 1) and Phase 2), with progression criteria assessed prior to progressing to Phase 2. In total, the trial will recruit 80 primary/junior schools in England, and 398 children (199 per arm) who screen positive for anxiety problems at baseline (target population). In schools allocated to 'screening and intervention': (1) parents/carers will complete a brief parent-report child anxiety screening questionnaire (at baseline) and receive feedback on their child's screening outcomes (after randomisation), (2) classes will receive a lesson on managing fears and worries and staff will be provided with information about the intervention and (3) parents/carers of children who screen positive for anxiety problems (target population) will be offered OSI. OSI will also be available for any other parents/carers of children in participating classes (total population) who request it. We will collect child-, parent- and teacher-report measures for the target population and total population at baseline (before randomisation), 4 months, 12 months and 24 months post-randomisation. The primary outcome will be the proportion of children who screen positive for anxiety problems at baseline (target population) who screen negative for anxiety problems 12 months post-randomisation.

DISCUSSION

This trial will establish if systematic screening for child anxiety problems, sharing screening outcomes with families and delivering a brief parent-led online intervention through schools is effective and cost-effective.

TRIAL REGISTRATION

ISRCTN registry ISRCTN76119074. Prospectively registered on 4.1.2022.

Effects of In-Classroom Physical Activity Breaks on Children's Academic Performance, Cognition, Health Behaviours and Health Outcomes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

In-Classroom physical activity breaks (IcPAB) are a promising way to promote children’s health behaviors, while contributing to the development of their academic and cognitive ability and health outcomes. Yet the effect of the activity breaks, which are exclusive to classroom settings, are still mixed and unclear. Hence, this review was conducted to identify the characteristics and the effects of IcPAB among primary school children. The review protocol was registered on PROSPERO (CRD42021234192). Following the Cochrane guidelines, PubMed, PsycINFO (ProQuest), MEDLINE (EBSCOhost), Embase/Ovid, SportDISCUS (EBSCOhost), Web of Science, Scopus and Academic Search Premier (EBSCOhost) databases were searched to collect data on randomised control trials without a time restriction. The final database search was conducted on the 8 November 2021. Random effects models were used to calculate the effect sizes. The systematic review identified ten eligible studies, nine of which were also included in the meta-analysis. Few studies used the theoretical frameworks and process evaluations. IcPAB showed mixed effectiveness on academic outcomes: i.e., IcPAB had effects on spelling performance (p < 0.05) and foreign language learning (p < 0.01) but not on mathematics and reading performance. Health behaviors such as moderate-to-vigorous physical activity levels were improved (p < 0.01), but IcPAB did not have an impact on cognition outcomes and health outcomes. Given these mixed results, further research is needed underpinned by strong methodological quality, theoretical underpinnings and reliable process evaluation methods.

Systematic review of the characteristics of school-based feasibility cluster randomised trials of interventions for improving the health of pupils in the UK

Background

The last 20 years have seen a marked increase in the use of cluster randomised trials (CRTs) in schools to evaluate interventions for improving pupil health outcomes. Schools have limited resources and participating in full-scale trials can be challenging and costly, given their main purpose is education. Feasibility studies can be used to identify challenges with implementing interventions and delivering trials. This systematic review summarises methodological characteristics and objectives of school-based cluster randomised feasibility studies in the United Kingdom (UK).

Methods

We systematically searched MEDLINE from inception to 31 December 2020. Eligible papers were school-based feasibility CRTs that included health outcomes measured on pupils.

Results

Of 3285 articles identified, 24 were included. School-based feasibility CRTs have been increasingly used in the UK since the first publication in 2008. Five (21%) studies provided justification for the use of the CRT design. Three (13%) studies provided details of a formal sample size calculation, with only one of these allowing for clustering. The median (IQR; range) recruited sample size was 7.5 (4.5 to 9; 2 to 37) schools and 274 (179 to 557; 29 to 1567) pupils. The most common feasibility objectives were to estimate the potential effectiveness of the intervention (n = 17; 71%), assess acceptability of the intervention (n = 16; 67%), and estimate the recruitment/retention rates (n = 15; 63%). Only one study was used to assess whether cluster randomisation was appropriate, and none of the studies that randomised clusters before recruiting pupils assessed the possibility of recruitment bias. Besides potential effectiveness, cost-effectiveness, and the intra-cluster correlation coefficient, no studies quantified the precision of the feasibility parameter estimates.

Conclusions

Feasibility CRTs are increasingly used in schools prior to definitive trials of interventions for improving health in pupils. The average sample size of studies included in this review would be large enough to estimate pupil-level feasibility parameters (e.g., percentage followed up) with reasonable precision. The review highlights the need for clearer sample size justification and better reporting of the precision with which feasibility parameters are estimated. Better use could be made of feasibility CRTs to assess challenges that are specific to the cluster design.

Trial registration

PROSPERO: CRD42020218993.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01098-w.

Minimising young children's anxiety through schools (MY-CATS): protocol for a cluster randomised controlled trial to evaluate the effectiveness and cost-effectiveness of an online parent-led intervention compared with usual school practice for young children identified as at risk for anxiety disorders

BACKGROUND

Identifying and supporting young children who are at risk of developing anxiety disorders would benefit children, families, and wider society. Elevated anxiety symptoms, inhibited temperament, and high parental anxiety are established risk factors for later anxiety disorders, but it remains unclear who is most likely to benefit from prevention and early intervention programmes. Delivering an online intervention through schools to parents of young children who have one or more of these risks could maximise reach. The primary aim of this trial is to evaluate the effectiveness and cost-effectiveness of delivering an online parent-led intervention, compared with usual school provision only, for children (aged 4-7) identified as at risk for anxiety disorders on the basis of at least one risk factor. We also aim to identify the characteristics of children who do and do not benefit from intervention and mechanisms of change from the intervention.

METHODS

The design will be a parallel group, superiority cluster randomised controlled trial, with schools (clusters) randomised to intervention or usual school practice arms in a 1:1 ratio stratified according to level of deprivation within the school. The study will recruit and randomise at least 60 primary/infant schools in England, and on the basis of recruiting 60 schools, we will recruit 1080 trial participants (540 per arm). Parents of all children (aged 4-7) in sampled Reception, Year 1, and Year 2 classes will be invited to complete screening questionnaires. Children who screen positive on the basis of anxiety symptoms, and/or behavioural inhibition, and/or parent anxiety symptoms will be eligible for the trial. Parents/carers of children in schools allocated to the intervention arm will be offered a brief online intervention; schools in both arms will continue to provide any usual support for children and parents throughout the trial. Assessments will be completed at screening, baseline (before randomisation), 6 weeks, 12 weeks, and 12 months post-randomisation. The primary outcome will be the absence/presence of an anxiety disorder diagnosis at 12 months.

DISCUSSION

The trial will determine if delivering an online intervention for parents of young children at risk of anxiety disorders identified through screening in schools is effective and cost-effective.

TRIAL REGISTRATION

ISRCTN 82398107 . Prospectively registered on Jan. 14, 2021.