Implementation fidelity of a transition program for adolescents with congenital heart disease: the STEPSTONES project

BACKGROUND: Although transition programs have been evaluated for adolescents with chronic conditions, these have rarely involved process evaluations. Indeed, outcomes of complex interventions are dependent on how the intervention is implemented in practice and evaluations of implementation process are therefore pivotal. The aim of this study was to evaluate the extent to which a transition program for adolescents with congenital heart disease was delivered as intended. Research questions were 1) to what level of fidelity was the program delivered? and 2) what potential moderating factors affected the delivery of the program and overall fidelity? METHODS: A mixed methods design was used, where a process evaluation was embedded in the STEPSTONES randomized controlled trial in Sweden. The implementation fidelity framework by Carrol (2007) and Hasson (2010) was used to design, collect and analyze data. Quantitative data consisted of intervention records on adherence and were analyzed with descriptive statistics. Qualitative data on moderators affecting fidelity were collected through interviews, log-books and focus group interviews with healthcare professionals implementing the intervention and participatory observations of the implementation process. Data were analyzed with deductive content analysis. Triangulation was used to integrate quantitative and qualitative data within the fidelity framework. RESULTS: Six out of eight components of the transition program were delivered to an extent that adhered to the program theory or achieved a high level of fidelity. However, components involving peer support had a low attendance by the participating sample (32.2%), and the joint transfer meeting was challenging to implement, despite achieving high adherence. Moderators affecting the implementation process were the adolescent’s and healthcare professional’s engagement in the intervention, contextual factors and a lack of standard operating procedures for all components in the program. CONCLUSION: Barriers and facilitators for a future implementation of transition programs have been illuminated in this study. The use of an implementation fidelity framework in the process evaluation proved successful in providing a comprehensive evaluation of factors affecting the implementation process. However, implementation fidelity must be considered in relation to adaptations to the local and personal prerequisites in order to create interventions that can achieve fit. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-022-07549-7.