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

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].