Incorporating psychological theory into the model of diffusion of innovations in healthcare

Evidence-based medicine calls for the use of current best evidence (together with individual clinical expertise). Guidelines aim to distil such evidence, yet clinical practice often fails to follow guidelines, for multiple reasons that are still not well understood. One under-researched aspect of the gap between guidelines and practice is psychology. My literature review found that the application of psychology to implementation research has been limited, and such research is not well integrated into wider implementation research. In this study, I sought to a) systematically apply psychological theory to understand the different psychological processes in the stages of adoption described in the diffusion of innovations model; b) collect and analyse data to explore and test this new, psychologically-enhanced model of guideline adoption; and c) improve and extend my model in the light of my empirical data. Having populated my proposed framework with potentially relevant psychological theories based on my literature review, I undertook a first assessment of the validity and added value of this proposed theoretical framework through a case study of the implementation of guidance on universal offering of HIV testing in hospitals serving populations meeting the criteria for high HIV prevalence in the catchment population, interviewing 20 healthcare professionals across two sites. My findings broadly supported my proposed theoretical approach, and illustrated relevant psychological theories for different stages of adoption. My findings support two provisional conclusions. First, that there is potential to improve the effectiveness of efforts to implement guidelines by augmenting the widely-used innovation adoption model with specific psychological theories. Second, that policymakers would do well to shift from viewing the health system as a complicated entity that policy can control and direct is misconceived; I recommend shifting to a perspective of the health system as a complex system, and rethinking the role of policy from that perspective.