Factors influencing the adoption, implementation, and continuation of physical activity interventions in primary health care: a Delphi study

The introduction of efficacious physical activity interventions in primary health care is a complex process. Understanding factors influencing the process can enhance the development of effective introduction strategies. This Delphi study aimed to identify factors most relevant for the adoption, implementation, and continuation of physical activity interventions in primary health care by examining experts' opinions on the importance and changeability of factors previously identified as potentially relevant for the process. In the first round, 44 experts scored factors on their importance for each stage of the introduction process, as well as on their changeability. In the second round, the same experts received a questionnaire containing a reduced list of factors, based on the first-round results. They were asked to indicate their top-10 most important factors for each stage, and to re-rate factors' changeability. Thirty-seven experts completed this round. Most important factors could be identified for each stage. Some factors were found important for a specific stage, e.g., the presence of intervention champions within the organization (adoption), provider knowledge (implementation), and the intervention's sustainability (continuation), while others were perceived important for all stages, i.e., the intervention's financial feasibility, the intervention's accessibility to the target group, and time to deliver the intervention. The majority of most important factors was perceived changeable. However, for some factors no consensus could be reached regarding their changeability. This study identified general and stage-specific factors relevant for the introduction of physical activity interventions in primary health care. It emphasizes the importance of taking these factors into account when designing introduction strategies, and of giving special attention to the distinct stages of the process. Due to lack of consensus on the changeability of most important factors, the extent to which these factors can be influenced by introduction strategies remains unclear.