General Articles

Implementation: The Factors that Affect Success for Evidence-Based Interventions


Joseph A. Durlak and Emily P. DuPre, “Implementation Matters: A Review of Research on the Influence of Implementation on Program Outcomes and the Factors Affecting Implementation,” American Journal of Community Psychology (June 2008).
Researchers at the Loyola University Department of Psychology reviewed thirty years of past research on interventions addressing a wide range of adolescent and child health behaviors. They sought to answer the questions, “(1) Does implementation affect outcomes, and (2) what factors affect implementation?” 1 They found reports on 542 interventions, and identified at least 23 ‘contextual factors’ that affect how programs are implemented. These contextual factors included community readiness, organizational capacity, the level of training provided to the program staff, and the role of program beneficiaries in planning and decision-making.
Key Findings:
·   No study has ever documented 100% perfect implementation for all providers; positive results in adolescent or child behavioral outcomes have been achieved with 60% implementation (i.e. 60% achievement of the 23 contextual factors); in only a few cases did implementation exceed 80%.
·   The greater the level of successful implementation, the more the program benefited participants in terms of knowledge, attitude, or behavior change.
·   Adaptations should not be seen as ‘failure to achieve program fidelity’; in fact, adaptations can often improve program outcomes.
·   Evaluations that neglect how a program was implemented are “flawed and incomplete”. 2
Sexuality educators know that the success of any educational program depends on how it is implemented. The same curriculum can result in very different outcomes for learners when delivered in different environments, led by different instructors, and paced at different intervals. Evidence-based interventions (“EBIs”), although rigorously evaluated using control groups and randomized selection, are just as vulnerable to these factors when replicated elsewhere.
With the recent Federal push for evidence-based interventions to prevent adolescent pregnancy, sexuality educators are increasingly aware of the importance of ‘program fidelity’, i.e. replicating an EBI as closely as possible to the way it was implemented in the study on which its success was based. However, sexuality educators are also aware that implementation does not occur in a vacuum. Without community and learner readiness, leadership and organizational support, and the capacity to make appropriate adaptations to meet learners where they are, sexual health promotion programs will not achieve the level of implementation needed to benefit adolescents. Sexuality educators should make every effort to document how their programs are implemented, to show what factors made the greatest difference for program success.
1 Durlak JA, DuPre EP (2008). Implementation matters: A review of research on the influence of implementation on program outcomes and the factors affecting implementation. American Journal of Community Psychology 41(3-4): 328. <>
2 Ibid. p.340.