A gloomy picture: a meta-analysis of randomized controlled trials reveals disappointing effectiveness of programs aiming at preventing child maltreatment

The number of parent support programs aimed at preventing or reducing child maltreatment
has grown over the last decades. Some of these programs were found to have a positive
impact on various parenting domains in studies using randomized controlled designs
(RCTs; 1]). However, consistent findings about the effectiveness of such programs to prevent
or reduce child maltreatment are lacking 2], 3]. The current meta-analysis aims to fill this gap. We synthesized findings of all
randomized controlled trials (23 studies) that tested the effectiveness of 20 different
programs, aimed at the general population, at-risk, and maltreating groups, in order
to reveal the overall success of programs to prevent or reduce the occurrence of child
maltreatment and to uncover factors that influence the effectiveness of intervention
programs.

Child maltreatment

A recent series of meta-analyses indicated that child maltreatment is a serious problem,
affecting children all over the world. Worldwide prevalence rates of different types
of maltreatment ranged from 0.3 % based on studies with reports from professionals
to 36.3 % based on self-report studies 4]. Risk factors for child maltreatment are low socio-economic status, parental mental
health problems, family isolation, and single parenthood 5]–7]. Child maltreatment is associated with short-term and long-term negative consequences.
Victims have an increased risk for physical, behavioral, and psychological problems,
also up into adulthood (e.g., 8]–11]), and benefit less from treatment compared to non-maltreated individuals 12], leading to high costs for individuals and society. Given the high prevalence rates
and serious consequences of maltreatment, effective prevention and reduction of child
maltreatment is essential.

Intervention programs

Over the last decades, the number of parent support programs has increased exponentially
1]. Most of these programs are targeted and provide support to a clearly defined population
identified on the basis of risk factors for child maltreatment. However, some programs
are available for everyone or at least for a large proportion of the population. Examples
of such universal programs are Triple-P 13] and SOS! Help for Parents 14]. These programs aim to prevent the occurrence of child maltreatment in the general
population, for example by using the media to inform parents about effective parenting
strategies or by providing a short parent skill training to parents who visit a well-baby
clinic. Concerning programs that target a clearly defined population, programs that
prevent the occurrence of child maltreatment in at-risk, but non-maltreating families, can
be distinguished from programs that reduce the incidence of child maltreatment in maltreating families.

A well-known targeted prevention program is the Nurse-Family Partnership developed by Olds and colleagues (e.g., 15], 16]). This program specifically targets pregnant adolescent women who are unmarried and/or
have a low income, but women without any of these risk factors are also allowed to
participate in the program. It consists of nurse home visits in the prenatal period
and during the first two years of the child’s life. The nurses promote improvement
of the women’s health behavior during and after pregnancy, help building supportive
relationships with family and friends, and link them with other needed services. The
Elmira (New York) trial indicated a significant difference of 80 % fewer child maltreatment
cases in the intervention group compared to the control group during the period of
intervention. However, these positive results disappeared in the two years after the
end of the program 17].

Parent–child Interaction Therapy (PCIT) is an example of a targeted program that aims
to reduce the incidence of child maltreatment in physically abusive parents. Families receive
14 weekly one-hour live-coached sessions of parent–child interaction training. The
training consists of child-directed interaction, in which the parent is instructed
to follow the child’s lead, and parent-directed interaction in which the parent is
taught to direct the child’s behavior and use consistent disciplinary techniques 18]. Several studies have shown that PCIT indeed effectively reduces child behavior problems
18], 19], and an RCT also indicated significantly fewer reports of physical abuse and improved
parenting skills in the PCIT condition compared to families who received community
services 20].

Prior meta-analytic findings

A number of meta-analyses have synthesized results on the effectiveness of intervention
programs aimed at preventing or reducing child maltreatment. However, some meta-analyses
did not specifically include papers that measured the actual occurrence of child maltreatment
21], 22], focused solely on non-maltreating families 23]–25], included only home-visiting programs 23], 25], 26], and/or included studies with less rigorous designs than RCTs 21], 23], 24]. For instance, Layzer and colleagues 21] combined abuse and neglect outcomes with child injuries, accidents, and removal from
the home into a single category ‘child safety’, which makes it impossible to estimate
the actual ability of programs to prevent or reduce child maltreatment. Geeraert and
colleagues 24] examined the effect of early prevention programs on actual abuse and neglect, but
they included mostly nonrandomized designs. A significant but small overall effect
on reported child maltreatment was found, but moderator analyses were not conducted.
Similarly, Filene and colleagues 23] examined the effect of home visiting programs on child maltreatment, but they also
included nonrandomized designs, and did not include maltreating families, thereby
only examining the preventive effect of interventions. In contrast to Geeraert and
colleagues, these authors did not find a significant effect on child maltreatment.
In another meta-analysis, only RCTs were included, but the focus of this meta-analysis
was solely on programs starting during pregnancy or within 6 months after birth 22]. It revealed a small but significant effect for maltreatment outcomes at the end
of intervention, but no effect at follow-up. The only significant moderator that was
identified for child abuse and neglect measures was year of publication; more recent
studies yielded smaller effect sizes.

The current study: Program effectiveness and moderators

The current meta-analysis aims to estimate the average effect of intervention programs
that provide services to parents in order to prevent or reduce child maltreatment.
We only included RCTs, in which participants are fully randomly assigned to either
the intervention or the control condition. Because of the random assignment, it can
be assumed that the two groups do not differ systematically before the start of the
program. Clustered randomized trials were excluded, because participants are not fully
randomly assigned and therefore participants (or their contexts) in one cluster may
not be comparable to participants in other clusters. Further, we aimed to include
three types of programs: those targeting the general population, aimed at preventing maltreatment, those for families at risk for child maltreatment, aimed at preventing maltreatment, and those specifically developed for maltreating families, aimed at
reducing maltreatment. We only included studies if they reported on actual maltreatment outcomes
and used this outcome in our meta-analysis. Child maltreatment was defined as “any
act or series of acts of commission or omission by a parent or other caregiver that
results in harm, potential for harm, or threat of harm to a child” (Centers for Disease
Control and Prevention (CDC)). In addition, we examined whether various intervention,
design, sample, and study characteristics were associated with program effects.

Intervention characteristics

An important characteristic of the intervention is the focus of the program. In some
programs, parents receive various sorts of support (e.g., social, emotional, material)
in order to build on strengths and improve overall family functioning, without actual
parenting skills training. For example, in Healthy Families America parents receive
support to reduce social isolation, access recourses such as food, housing, employment,
and health care, and improve their knowledge about child development 27]. Other programs do provide actual training for parents to improve their parenting
skills, such as SOS! Help for parents 14], in which parents are instructed about (the role of) parenting skills and common
mistakes in parenting, or Parent Child Interaction Therapy 20], in which parents receive (among other things) live parent–child coaching sessions
to improve parent–child interaction skills. Finally, some intervention programs combine
parent training and support. For example, in the Project Support intervention 28], mothers are taught skills for child behavioral management by instruction, practice,
and feedback, and they are provided with instrumental and emotional support, such
as training in how to evaluate a child care provider.

Further, the way of delivery is another intervention characteristic that can differ
substantially between programs. Some programs use support-groups in a center-based
setting 29], others consist of personal home visits 15] or combine center-based and home-based sessions 30]. The number of sessions and the duration varies from program to program. For instance,
in the Nurse-Family Partnership Program 15], parents receive 45 home visits during the first two years of the their child’s life,
while the SOS! Help for parents program (SOS) described by Oveisi and colleagues 14] consists of only two 2-h weekly sessions. A meta-analysis on the effectiveness of
interventions aimed at improving parental sensitivity and parent–child attachment
revealed that programs with fewer contacts were more effective in improving sensitivity
and attachment 31], but it is unclear if this is also true for programs aimed at preventing or reducing
child maltreatment. Last, and more specific for programs aimed at preventing child
maltreatment, the moment of onset of the program, and thus the age of the child at
the start of the program, has been discussed as an important moderator of a program’s
effectiveness. Although it has been suggested that programs for the prevention of
child maltreatment would be most effective if starting before birth 1], meta-analytic evidence showed that programs focusing on parental sensitivity or
parent–child attachment that started 6 months after birth were at least as effective
as programs with an earlier onset 31].

Sample characteristics

Intervention programs target different populations. Universal programs target the
general population, while targeted programs focus on a clearly defined group of families
at risk for child maltreatment or maltreating families. Some have suggested that programs
with a clear target population would be more effective 32]. This may be especially true for programs that target maltreating families, because
those families show the behaviors that are targeted for change, and therefore they
may have the greatest potential for demonstrating change.

Design characteristics

The rigor of the study design may also affect the effect size. Studies with poorer
methodological designs likely yield larger effect sizes 3]. The use of intent-to-treat analyses is an example of a methodological strength,
as selective refusals after randomization or selective attrition during the intervention
may affect the randomization. In intent-to-treat analyses, group differences are analyzed
based on the original random assignment. Other design characteristics are sample size,
whether assessment was blind for group assignment and whether a pretest was included.
Moreover, the type and amount of services received in the control condition differs
between programs. Largest effect sizes may be expected when the control group received
few or even no services. In addition, there may be differences in effect sizes for
short-term and long-term effects. On the one hand, it may be expected that intervention
effects decrease or even disappear over time. On the other hand, there may be sleeper
effects, meaning that intervention effects increase over time, because parents would
need some more time to practice new skills 33]. Finally, the method of assessment of child maltreatment may influence effect sizes.
Although self-report measures may be informative since participants may know their
own experiences best, self-reports have several disadvantages. Participants may interpret
definitions of maltreatment or parenting practices differently than researchers and
it may be difficult for participants to remember the exact frequency of specific events
in the past. In addition, self-report of maltreatment experience is not possible in
early childhood. In contrast, reports from professionals who work with children do
cover all ages and these reports are generally coded by expert coders who use the
same set of definitions. The downside of this method is that professionals may not
be aware of all cases of maltreatment; they may only see the tip-of-the-iceberg 34].