Objectives

A 2010 article by the Conduct Problems Prevention Research Group considers an important social and public policy problem: can early psychosocial intervention prevent delinquency? The article examines the effects of the Fast Track preventive intervention on youth arrests and self-reported delinquent behavior through age 19. The article reports that the intervention reduced court-recorded juvenile arrest activity as well as a range of other disparate effects.

Methods

This comment assesses the methodology employed in the article.

Results

The original article suffers from a range of methodological problems. First and foremost, the article includes a large number of statistical tests and highlights only a subset that are statistically significant. As this article demonstrates, these findings likely involve “false discoveries” or chance findings. Uncertainty about the study’s findings is increased still further by problems of randomization, the treatment of site, the handling of missing data, and the inclusion of a collider as a covariate in key analyses. A proper assessment of the study’s meaning and implications has been impeded by inaccuracies in how the study’s methodology has been described over time.

Conclusions

The original article offers chance findings, suffers from methodological errors and builds on a flawed study design. As a result, it is impossible to conclude that “that a comprehensive preventive intervention can prevent juvenile arrest rates”. What the intervention would accomplish were it implemented in a new community is unknown.