few differences between the two intervention conditions, although this could have been due to the low statistical power for this school-based design.
An ongoing randomized trial of two different methods of implementing an evidence-based program for foster care in California counties may shed new light on implementation approaches. The trial was driven by a California mandate to use evidence-based practices and interest in identifying ways to facilitate statewide implementation. Although this particular trial involves multidimensional treatment foster care (Chamberlain, Saldana, et al., in press), an evidence-based program that targets high-need children who are in state custody, it can also be enlightening for the implementation of evidence-based prevention. Training had earlier been offered to all California counties, but only about 10 percent of the counties became early adopters, not unlike that of most novel interventions (Rogers, 1995; Valente, 1996). All the remaining 40 eligible counties were randomly assigned to one of two methods for implementation: a standard model and a community development team model, which used cross-county peer-to-peer support to address the administrative, financial, and logistical challenges in implementing the program. The evaluation is assessing whether the rate and length of time for adoption and sustainability is reduced by the team model, taking into account the dependence between team members.
The rate of adoption of a particular program across different communities and the rate of participation in a community are major issues that affect levels of program implementation. A variety of potential approaches to increase these rates could be evaluated in future research.
The general class of randomized “encouragement designs” are ones that randomize individuals to different modalities of recruitment, incentives, or persuasion messages to influence their choice to participate in one or another intervention condition. Such incentives as cash or child care discounts have been used to encourage participation. An important advantage of these designs is that they allow one to take into account self-selection factors in examining impact (Yau and Little, 2001; Frangakis and Rubin, 1999; Barnard, Frangakis, et al., 2002). They also address whether targeted efforts to increase participation reach those most at risk (Brown and Liao, 1999). Randomized encouragement trials have been used to evaluate early versus late enrollment in Early Head Start (Administration for Children and Families, 2005), whether antiviral medications for HIV should adhere to a rigid regimen or be more flexible (HIV SMART AntiRetroviral Trial),