My point in writing the editorial1 that accompanied Dr Reynolds' article2 was to say that vulnerable children and families will be better served if policies and practices have a stronger foundation in replicated RCTs. Dr Reynolds and his team have made good use of the data that are available to them, but the quasi-experimental nature of this study creates limits that deserve consideration.
Olds DL. Strong Design and Comprehensive Analysis of the Child-Parent Center Study—Reply. Arch Pediatr Adolesc Med. 2008;162(11):1100. doi:10.1001/archpedi.162.11.1100