Interventions with individual children often have an effect, but there is little evidence that children as a whole benefit, according to a paper by Kenneth Dodge, from Duke University, USA, who calls for a radical shift in how prevention science operates.

He writes: “Although numerous developmental-science-based interventions have been found to have favorable impact on the narrow group of children that have been targeted for these interventions, few have demonstrated a positive effect on the entire population of children in a community.”

He claims that the assumption that findings readily generalize from the laboratory context to the community context is false. “No one context is more or less ‘real’ than any other context, but some contexts are more ecologically important than others,” he writes. “Pulling a phenomenon out of its natural context into the laboratory context for purer scrutiny runs the risk of losing the phenomenon altogether because it gets divorced from the contextual circumstances that define the phenomenon.”

He goes on: “Translation science supposedly moves from the rigor and purity of basic science to the messy reality of the community context. The problem with this model is that it just does not work. When a phenomenon is taken out of its context, it becomes a different phenomenon. Translation often fails.”

This is ironic, says Dodge, because one of developmental science’s most important contributions has been to articulate how context makes a difference and renders findings from one context invalid in other contexts.

“We still need to learn that intervention research conducted in the context of efficacy trials, with volunteer participants, limited samples, and ideal intervention fidelity, does not readily generalize to intervention as implemented in community settings,” he writes.

He is quick to praise randomized controlled trials of systematic intervention to improve children’s development, mostly focusing on parenting, peer context and how people process information in social interactions. Many of these show that there is promise in some of these interventions and yield important insights for developmental theory. But they fail to demonstrate impact on the population of children.

Dodge gives the example of parent-training programs, which have been found to improve children’s behavior by enhancing the use of contingent praise and decreasing coercive harsh discipline.

He argues: “Their population impact is minimized by the fact that most are voluntary, and getting agreement to participate is a challenge, while the exclusion criteria for participation often keep out families that are in high need. “In many cases, families must speak English or they must agree not to move out of the school district or neighborhood (or if they do, they get excluded from data analysis as missing values).”

He gives the example of the highly successful and well-regarded Nurse Family Partnership program, asking what would be the likely impact on the community rate of child maltreatment if home visiting programs like it were to be funded for a community.

Dodge is not optimistic. First, NFP is offered only to a small group of women: first-time, low-income
mothers who can be identified before the end of the second trimester. Second, NFP trials were conducted with women who voluntarily consented to participate. Dodge says that “studies of volunteer programs for mothers are known to have difficulty in recruiting and sustaining mothers who have been involved in child welfare services, are substance using, or are mobile.”

Further problems are that only a third of women who start a home visiting program actually complete it, and fidelity of implementation often declines when a program is implemented in the community, reducing its effectiveness.

Last, when a program is implemented at scale, the community context changes in unanticipated ways.

Dodge explains: “For example, because one stated goal of home visiting programs is to refer mothers to community services, such as substance abuse and mental health treatment, the strain on the community when a program is implemented at scale might become overwhelming.

“The point here is that the context in which a dissemination effort is conducted is likely to differ from the context in which the efficacy trial on which it is based was conducted. The act of implementing a program at scale can change the context.”

Dodge’s proposed solution is creative evaluation designs that include the entire population, not only those individuals who consent to provide information about themselves.

He writes: “Entire communities can be randomly assigned to an intervention policy, although this design often requires high funding levels. Administrative files can be used to generate outcome data for populations of children in a way that does not require individual informed consent, such as when the average academic test score for a school is used as the outcome variable in intervention research.”

He concludes that, “Successful translation is not likely to come through replication of the very same intervention program applied at scale without consideration of changes that must account for the differences in context.

“Community population impact is not going to occur by following manuals from efficacy-trial-based programs. Rather, successful population-level impact is more likely to occur by creating community contexts that support important principles in child development, such as consistent positive parenting, supportive peer influences, and child social-cognitive skills.”

Reference:
Dodge, K. A. (2011) ‘Context matters in child and family policy’ Child Development 82 (1), 433-442.