Background
The World Health Organization (WHO) has declared ‘violence a leading worldwide public health problem’ [
1,
2]. In 2013, interpersonal violence (outside of combat situations) caused 405,000 deaths and 29.5 million injuries warranting medical attention worldwide [
3]. Latin America has the highest regional homicide rate [
4]. Globally, round half of all children are exposed to some form of violence each year [
5,
6] and 30% of women experience lifetime intimate partner violence [
7]. In Brazil, the most populous Latin American country, interpersonal violence, mainly between young males, is the second leading cause of years of life lost after heart disease [
8], and its economic cost is estimated at 5% of annual GDP [
9]. Non-fatal violent victimisation is associated with a range of mental health problems, sexually transmitted diseases, and risk behaviours linked with chronic disease [
10‐
12]. Key international bodies therefore consider global prevention of violence to be a priority [
6,
13]. For example, UN Sustainable Development Goals 5 and 16 require major reductions in violence by 2030. Notably, the biggest challenges are in high-violence LMIC contexts, where data are particularly scarce on the effectiveness of preventive interventions [
14‐
16].
Early interventions that reduce risk factors for violence are potentially important public health prevention strategies [
17]. Some evidence suggests that such an approach could be effective. Thus, randomised trials of intensive nurse home-visiting and preschool enrichment programmes in the USA have found reductions in child maltreatment [
18] as well as in children’s own future crime perpetration and violence [
19]. Cost-benefit analyses show that much of the large, long-term gains of such early intervention programmes are driven by crime reduction [
20]. However, in LMIC settings, the elevated short-term costs of most existing programmes and their need for highly trained professionals make them impracticable, and, to date, there has been little interest in the application of such preventive strategies in LMICs.
However, brief, less expensive, programmes supporting parents without the need for highly specialised professionals are potentially affordable in LMICs, and might have large benefits for children residing in impoverished environments [
21,
22]. Although randomised controlled trials (RCTs) of parenting interventions have shown promising results in HICs [
19,
23‐
26], few trials have been conducted in LMICs. A systematic review located only 12 such trials in LMICs by 2013 [
27] with just two demonstrating adequate power and low risk of bias – and neither examined child behavioural outcomes.
The WHO has declared an urgent need for the evaluation and implementation of low-cost parenting interventions in LMIC contexts to prevent violence [
28]. Several early family and personal factors are associated with increased risk for children’s persistent aggression – a key precursor of later violence perpetration [
29]. Parenting programmes potentially could reduce children’s risk for developing persistent child aggression in two key ways. The first is by promoting parenting that provides good cognitive support to children (improving child learning and school readiness); and the second is reducing harsh and abusive parenting. There is robust evidence that interventions that help parents support their children’s cognitive development can be effective [
30]. There is also evidence that parents can be helped to reduce harsh and abusive parenting [
18]. The problem for LMICs is that parenting interventions that have been shown to be effective tend to be specialist and long term, which makes them, as noted, unaffordable in LMIC contexts. It is critical to the agenda of scale-up in LMIC settings that interventions are developed and evaluated that are affordable and deliverable by non-specialist personnel.
Current trial
The Pelotas Trial of Parenting Interventions for Aggression (The PIÁ Trial) aims to evaluate the efficacy of two brief, parent-training programmes for reducing early child aggression. The study is being run in the city of Pelotas in southern Brazil, a LMIC. The trial is evaluating two low-cost, manualised parent-training programmes. These are: (1) a ‘dialogic book-sharing programme’ (DBS) that aims to improve child cognition and social understanding [
31‐
33], and (2) ‘ACT: Raising Safe Kids program’ (ACT), which aims to reduce harsh parenting and child maltreatment [
34]. The two interventions therefore target both sides of the individual and parenting risks highlighted above, putatively linking adverse environments to persistent child aggression. A three-arm RCT is being used to evaluate the impact of the two programmes. Interventions are being provided by local government personnel (i.e. primary care workers for DBS and school education coordinators for ACT) whom our team has trained as facilitators. The population participating in the trial is a high-risk subset – in terms of poverty and child aggression – of an ongoing birth cohort study, the 2015 Pelotas Birth Cohort Study [
35]. Independent assessments are being made of child aggression, as well as the two key risk factors, child cognition and harsh parenting. Additional assessments are being made of broader parenting practices and child developmental progress. Assessments are being made on three occasions: before the intervention (when children are aged between 30 and 42 months), shortly following the intervention, and at a 6-month follow-up when the children are aged 4 years.
Outcomes
Assessments
Detailed assessments of the trial participants are being made at baseline and will be conducted on two occasions post intervention: 4 weeks following the end of the interventions and then at a the 6-month follow-up (see Table
3 below).
Table 3
Study outcomes and measures
Child aggression (primary outcome) | Child aggression | Aggression sub-scale of the Child Behaviour Checklist | ✓ | | ✓ |
Items on aggression from the ELDEQ Study Questionnaire | ✓ | | ✓ |
Observation: Don’t touch’ and ‘Clean Up’ tasks | ✓ | | ✓ |
Observation: LabTab, ‘Don’t touch’ and ‘Clean Up’ tasks | ✓ | | ✓ |
Child language (main secondary outcome) | Expressive language | Teste de Vocabulário Expressivo | ✓ | | ✓ |
Receptive language | Teste de Vocabulário Receptivo | ✓ | | ✓ |
Parenting (main secondary outcome) | Harsh and abusive parenting | PAFAS Questionnaire | ✓ | | ✓ |
Juvenile Victimisation Questionnaire | ✓ | | ✓ |
Observation: Don’t touch’ and ‘Clean Up’ tasks | ✓ | | ✓ |
Searches of child protection service records | | | ✓ |
Parenting (secondary outcomes) | Positive parenting | PAFAS Questionnaire | ✓ | ✓ | |
Videotaped sensitivity and reciprocity during book-sharing and free-play parent-child interactions | ✓ | ✓ | |
Parental attitudes about corporal punishment | Deater-Deckard study Questionnaire | ✓ | ✓ | |
Stress (secondary outcomes) | Parental stress | Perceived Stress Scale | ✓ | ✓ | |
Pelotas questions on parenting stress | ✓ | ✓ | |
Parental and child chronic stress | Cortisol from hair samples | ✓ | | ✓ |
Child development (secondary outcomes) | Child attention | Strengths and Difficulties Questionnaire | ✓ | | ✓ |
Card Sort task from the Early Years Toolbox | | | ✓ |
Child executive functions/self-control | Go no Go task from the Early Years Toolbox | ✓ | | ✓ |
Block Design task | ✓ | | ✓ |
Child emotion recognition | Denham’s puppet task | ✓ | | ✓ |
Child empathy/theory of mind/altruism | Em-Que Questionnaire | ✓ | | ✓ |
Help task | ✓ | | ✓ |
Dictator Game | | | ✓ |
Triangle task | ✓ | | ✓ |
Sally-Anne task | | | ✓ |
The primary outcome is child aggression at the 6-month follow-up assessment, measured by parental report, and direct observation. The parent report measures include two questionnaires: the Aggression sub-scale of the Child Behavior Checklist (CBCL) [
55] and items on aggression from the ELDEQ Study Questionnaire [
39]. Three observational measures are being used: child response to a frustration task (from the
Laboratory Temperament Assessment Battery for preschool children,
www.uta.edu/faculty/jgagne/labtab), and child behaviour during ‘Don’t touch’ and ‘Clean Up’ tasks [
56,
57]. The multiple measures of aggression will be combined into at least one latent variable for analysis of the primary outcome, and the independent trial statistician will decide if a single variable or multiple latent variables are required (for example, one for observed aggression and one for reported aggression).
The two main secondary outcomes will be measured at the 6-month follow-up. All relevant measures are being administered to the whole trial sample, but effects are hypothesised to be specific to DBS or ACT, as outlined above:
2.
Harsh and abusive parenting will be assessed by parent self-report, using the PAFAS Questionnaire [
58], the Juvenile Victimisation Questionnaire (
http://www.unh.edu/ccrc/jvq/index_new.html), by direct observation during the ‘Don’t touch’ and ‘Clean Up’ tasks [
56,
57], and by searches of child protection service records
Additional secondary outcomes will be measured at the 4-week post-intervention assessment (#1–4 below) and at the 6-month follow-up (#5–8).
1.
Positive parenting will be assessed using the PAFAS Questionnaire, and videotaped sensitivity and reciprocity during book-sharing and free-play parent-child interactions (as successfully used in previous book-sharing trials) [
31‐
33]
2.
Parental attitudes about corporal punishment will be assessed using by the Deater-Deckard Study Questionnaire [
59]
3.
Parental stress will be assessed using the Perceived Stress Scale [
60] and Pelotas questions on parenting stress
4.
Parental and child chronic stress will be assessed by cortisol from hair samples [
61‐
65]
5.
Child attention will be assessed using the Strengths and Difficulties Questionnaire [
66] and the Card Sort task from the Early Years Toolbox [
67]
6.
Child executive functions/self-control will be assessed using the Go no Go task from the Early Years Toolbox [
67], the Block Design task, and assessor ratings
7.
Child emotion recognition will be assessed using Denham’s puppet task [
68]
8.
Child empathy/theory of mind/altruism will be assessed using the Em-Que Parent Questionnaire measure [
69], the Help task [
70], the Dictator Game [
71], and the Sally-Anne task [
72]
All the outcome measures specified above are being taken at baseline, except the Dictator Game measure of altruism and the Card Sort Game, which were judged to be less amenable to repeat application over a short period of time, and the Sally-Anne task (for empathy, the Triangle task [
73] is being used at baseline, but concerns about how well it is functioning require an additional measure for follow-up)
Potential moderators
The following variables will be examined as potential moderators: parental education, parental mental health, domestic violence, and maternal and child stress, maternal harsh parenting, number of siblings, and child sex, age, and aggression.
Data management
Participants are being assured of the confidentiality and anonymity of their data. Data are being anonymised by using ID codes which are kept in secure storage on Federal University of Pelotas premises, with individuals’ personal, identifiable details kept separate from all other information. The anonymised electronic data will be archived at the Federal University of Pelotas, Centre for Epidemiological Research data storage and archive division (under the supervision of Cauane Blumenberg, Research Data Manager). Data will be made available to the academic community via requests being sent to the Pelotas Cohorts Publications’ Committee. Sensitive data will be stored in the archive under a restricted access setting, accessible to the data depositor and archive administrative staff only.
Data analysis
Data analysis will be completed by a designated statistician, Merryn Vossey from the Oxford University Department of Primary Care Medicine, who will work independent from study investigators. Group baseline differences will be investigated including socio-demographic data, such as child sex, and household factors (e.g. income, relationship status), and study outcomes.
The primary and secondary outcomes will be analysed using linear mixed models, which can account for repeated assessments within individuals (for outcomes measured at multiple time-points). Intervention effects will be assessed at post intervention and follow-up and will be adjusted for child’s age, sex, and baseline scores (where applicable). Further socio-demographic factors may also be investigated as covariates. If the necessary assumptions of the models do not hold, suitable alternative models will be fitted. Intention-to-treat analysis will be used to examine intervention effects. Sensitivity analyses will examine if intervention effects maintain for measures that are not dependent on parent report, which may be biased because parents are not blind to the interventions.
The amount and pattern of missing data will be examined and will be addressed using multiple imputation where appropriate. Due to the multiplicity of comparisons, caution will be used in interpreting results of secondary outcome comparisons. No single p value will be interpreted in isolation and all findings will be considered together to obtain the full picture of the intervention effects on the different outcome measures.
Mediator analyses will aim to identify active components of the interventions and elucidate the pathways to change. To this end, the following question will be examined: whether the impact of the interventions on child aggression is mediated by improvements in child cognition and by reductions in harsh parenting.
Moderator analyses
Moderator analyses will be conducted to investigate whether certain groups respond differently to the interventions. In addition to the potential mediators listed above, we will examine the impact of number of intervention sessions attended. Potential mediators and moderators of the intervention will be examined using mixed linear models or structural equation modelling, as appropriate.
Trial monitoring
Trial Steering Committee
An independent Trial Steering Committee (TSC) is monitoring the progress of the trial and advises the research team on matters arising during the course of the study. The PI (JM) consults with the TSC Chair once a month and the TSC meets biannually. The TSC is chaired by Prof Cathy Ward (Chair), Department of Psychology, University of Cape Town. Other external academic representation is provided by Prof Manuel Eisner, Institute of Criminology, University of Cambridge; Prof Pasco Fearon, Division of Psychology and Language Sciences, University College London, and Dr. Christian Kieling, Department of Psychiatry, Federal University of Rio Grande do Sul. Marilia Mesenburg, a mother of a child in 2015 Pelotas Birth Cohort Study (not selected for the trial) represents the local Pelotas community. TSC members from The PIÁ Trial study team are JM and IS.
Discussion
The PIÁ Trial is an evaluation of two parenting interventions, both with the potential to reduce risk for later offspring violence. The DBS intervention targets child cognitive function/social understanding, which is implicated in the development of persistent child aggression, itself a strong predictor of later violence. The ACT programme targets harsh parenting and maltreatment, also associated with child aggression and later violence. The interventions are being delivered to mothers of 30–42-month old children in the Brazilian city of Pelotas, a city with a high rate of socio-economic disadvantage and a very high level of violence. The interventions are being delivered by trained facilitators, during weekly sessions over 8–9 weeks, to small groups of mothers. The primary outcome of The PIÁ Trial is child aggression. The two main secondary outcomes are child language and harsh parenting. A number of other assessments are being made, both of parenting and of child developmental progress. Parental reports of child behaviour may be biased because parents are, of course, not blind to their intervention status. However, The PIÁ Trial also includes observational measures of child behavior and parenting, direct tests with children, as well as external data sources (records), reducing this bias.
A major strength of the trial is that it is embedded within a birth cohort study, and the intention is to follow-up the cohort, including the trial participants, over many years. Indeed, The PIÁ Trial will be one of the few studies of early parenting interventions aiming to assess offspring outcomes into adulthood, and perhaps the only early parenting trial aiming to investigate long-term impact on aggression through the life-course [
74].
Outcomes, outputs, and dissemination
Following receipt of the trial statistical report, we will disseminate the study findings in several ways. We will publish them in peer reviewed academic journals and in relevant professional journals. We will produce a summary of the project’s objectives, methodologies, and key findings, together with recommendations for policy and practice, which will appear on the Federal University of Pelotas University and Instituto Cidade Segura websites. We will also write a briefing paper for distribution to the local government of Pelotas and local and regional press.
Acknowledgements
The study is sponsored by The Federal University of Pelotas in Brazil. We are very grateful to the mayor of Pelotas, Paula Mascarenhas for her support of the trial, and to Samuel Ongaratto for general coordination of the implementation of the interventions, the staff of the Primeira Infância Melhor programme, under the supervision of Maria de Lourdes Botelho, and the staff of the Pelotas public schools, under the coordination of Aliceia Ceciliano. We are very grateful to Merryn Vossey for guidance on the data analytic strategy, Julia da Silva for supporting the running of the ACT programme in Pelotas, Andrea Lopes and Ricardo Brandolt for their help mapping the families that participate in the study, and all the interviewers and administrative staff working on the project. We are also very grateful to the members of the Trial Steering Committee. Finally, we wish to express our sincere thanks to the families taking part in the research.