Detecting and describing preventive intervention effects in a universal school-based randomized trial targeting delinquent and violent behavior.

Abstract

This study examined theoretical, methodological, and statistical problems involved in evaluating the outcome of aggression on the playground for a universal preventive intervention for conduct disorder. Moderately aggressive children were hypothesized most likely to benefit. Aggression was measured on the playground using observers blind to the group status of the children. Behavior was micro-coded in real time to minimize potential expectancy biases. The effectiveness of the intervention was strongly related to initial levels of aggressiveness. The most aggressive children improved the most. Models that incorporated corrections for low reliability (the ratio of variance due to true time-stable individual differences to total variance) and censoring (a floor effect in the rate data due to short periods of observation) obtained effect sizes 5 times larger than models without such corrections with respect to children who were initially 2 SDs above the mean on aggressiveness.

Substance use outcomes 5½ years past baseline for partnership-based, family-school preventive interventions

“…As has been observed in other schoolbased intervention studies (e.g., August et al, 2001;Brown and Liao, 1999;Kellam et al, 1998;Stoolmiller et al, 2000), significant intervention effects were in evidence for a higherrisk subsample, absent effects for the full sample. Twelfth grade point-in-time intervention effects for LST-only were significant for all outcomes; corresponding LST + SFP 10-14 effects were significant for all outcomes except alcohol and drunkenness frequencies.…”

Early intervention for at risk children: 3-year follow-up

“…6,7,8,9 Others have demonstrated a similar phenomenon. 10,11,12 Although often effective, universal interventions have the disadvantage that most children participating are low-risk and do not require intervention.…”

“…23 The data also showed that the higher the initial problem score, the steeper was the decline, consistent with findings elsewhere. 6,7,8,9,49 This may be attributable to so-called 'discrepancy proportional peer influence' so that the behaviour of those at the extremes is drawn toward the group mean. 50 If this is true, it requires the presence of some less overtly deviant peers in the therapeutic group.…”

Reducing the Risk of Disordered Eating Among Female College Students: A Test of Alternative Interventions

“…Because previous research has indicated that individuals who suffer from eating disorder symptoms are not likely to seek treatment (Welch & Fairburn, 1994) and that intervention effects are greatest for people with initial elevations in disordered attitudes and behaviors (Franko, 1998), intervention programs aimed towards this specific female population (e.g., targeted) may help reduce eating pathology and create healthier alternatives. Specifically, programs aimed toward individuals with initially elevated symptoms produce the greatest effects (Lowry-Webster, Barrett, & Dadds, 2001;Stoolmiller, Eddy, & Reid, 2000), because the subjective distress that characterizes high-risk individuals motivates these participants to become more engaged in the program. Additionally, strategies, such as implementing intervention or prevention programs, to interrupt the progression of disordered eating patterns at the earliest possible stage (e.g., when individuals are most at risk to become body dissatisfied and/or develop disordered eating attitudes or compensatory behaviors) are imperative to minimize any harmful effects and to attain psychological and physical well-being.…”

“…These programs (a) are offered to high-risk individuals because they may be more willing to commit to the intervention due to their high levels of distress and because they are most likely to evidence change as a result of the treatment (Stice, Mazotti, Wiebel, & Agras, 2000;Stoolmiller, Eddy, & Reid, 2000), and (b) utilize interactive exercises and homework to apply and integrate the skills taught in the intervention (Stice & Shaw, 2004). Further, college students are an ideal group to target for such interventions because eating pathology is most likely to emerge during this time of life (Lewinsohn, 2000;Stice, Killen, Hayward, & Taylor, 1998), and because programs are most effective when delivered during the period in which eating disorder symptoms are emerging (Maggs, Schulenberg, & Hurrelmann, 1996).…”