Early intervention will be understood – sooner of later

It is getting into the woodwork of policy making that corrective early intervention in children’s development, will be more productive and enduring than anything tried later.

In certain UK cities, for example, the promise of long-term health benefits and service cost savings already supports an elaborate edifice of program management and cost-benefit investment strategies.

But, as a team of University of Illinois researchers observe in the journal Prevention Science, the principles of early intervention are relatively untested, and the factors influencing sustained long-term effects understudied.

“In some cases,” Patrick Tolan and his colleagues observe, “the long-term effects of early intervention are mistakenly presented as evidence that early intervention is preferable, but this is not an actual test of timing”.

Among rare empirical investigations they cite the Chicago Metropolitan Area Child Study [1] in which the results of exposure to a violence prevention program in second grade were compared to results from an identical experience starting in fifth grade. What worked at second grade did not work at fifth.

The Illinois researchers are interested in the value of “booster” interventions and the argument that the long-term potential of early intervention can be secured and enhanced by a strategically-timed top up.

As with early intervention itself, what evidence there is supports the principle – but it is not as extensive nor as compelling as some advocates might be beginning to assume.

Tolan believes that their work in an inner city area of Chicago, using a family management program called Schools and Families Educating Children [2] (SAFEChildren), is the first to have used random assignment to test the “booster effect”.

Just under 200 families took part. The parents were given help managing their children’s transition to school (first grade); their children received 20 academic tutoring sessions.

At one-year follow-up all of the participants showed “modest but statistically significant” benefits. Among families where pre-intervention risks were greatest, the improvements were more pronounced.

The Illinois booster was given to a randomly assigned 50% of the original intake during fourth grade “just prior to the age when delinquency and other social problems are emerging”.

It added a developmentally adjusted mixture of group discussion and behavioral practice around effective parenting, student motivation and the threats to equilibrium. All of the activity was in keeping with the pattern of the original program.

The comparison between the two groups was based on the results of a range of reports and standardized tests, and – as far they went – the findings were encouraging. They suggested “a relative boost in effects over the initial intervention” and so “modest support” for the frequent contention that boosters are a good thing

But the benefits were not found consistently across the board and for theoretically important mediators of long-term child risk, such as parental monitoring and school bonding, the second injection made no difference.

Beyond their guarded recommendations, Tolan’s team flag up more fundamental problems associated with judging effectiveness in relation to timing – early, late or both.

“While one can imagine a research design that might mix the timing of booster and initial intervention, or apply an attention control to balance dosage, the practical challenges of carrying out such studies are considerable, and perhaps implausible to circumvent,” they write.

“If one were to stagger follow-up such that time-since-intervention was the same for those exposed to a booster and those not, then the age-at-outcome measurement would be confounded, imposing other interpretation problems.”

As for the beneficial processes they observed, more conjecture: “The ‘boost’ may arise from consolidating propensities set forth in the initial intervention or by strengthening skills that are critical for managing developmental challenges that are more figural during this time just before adolescence.”

Or it might be that the “protective academic success” and continued parental involvement attributable to the initial intervention created a platform for the booster to build on.

Or supporting effective parenting practices and strong family relationships early on might have enhanced a propensity that emerged as children neared adolescence, when they might otherwise be more vulnerable to heightened aggression.

Or the booster might also have improved a family’s ability to ride out the changes in their growing children’s behavior, just by providing them with more and better information.

And between all these uncertainties, the Chicago researchers interleave a more definite limitation: the SAFEChildren booster program was as lengthy and complicated as the original.

See: Tolan P, Gorman-Smith D, Henry D and Schoeny M (2010) "The benefits of booster interventions: evidence from a family-focused prevention program", Prevention Science, 10, 4, pp 287-297

See also: Early surely does it (but just how early is early?) [3]