The complexity of implementation factors in professional pharmacy services.

Implementation of professional pharmacy services is a complex process, in which multi-level factors interact and influence implementation process and outcomes at various levels or domains. In this paper the terms that have been used to describe the factors that influence implementation of evidence-based services and their domains are presented. The complex 'cause-and-effect' interactions by which implementation factors appear to interact throughout the implementation process are also discussed. Identifying and understanding these complex and causal relationships between different implementation factors, represents a key process in the implementation of any service, in order to assist in the development of tailored implementation strategies. Future research should be directed to gain an understanding of the nature of individual implementation factors, their cause-and-effect interactions, and their relationships. Implementation strategies are less likely to succeed unless these are identified and targeted to the causes identified when designing and planning an implementation strategy.