Browse by author
Lookup NU author(s): Dr Louise Robinson
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2026 Griffiths et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction: Refining programme theory following feasibility testing is a critical but rarely reported step in the development of complex interventions, creating a ‘black box’ in implementation science. This lack of transparency limits understanding of how and why interventions work and constrains effective scale-up and adaptation. This challenge is particularly salient in post-diagnostic dementia support, which is often fragmented in primary care, with limited guidance on how system-level interventions can be implemented and adapted in real-world settings. The PriDem programme developed a flexible, primary care-led intervention to improve post-diagnostic dementia support, involving Clinical Dementia Leads (CDLs) working with general practices to strengthen care systems. Programme theory was articulated in a logic model, to guide a feasibility implementation study, which demonstrated intervention feasibility, acceptability, and potential for systems-level change. Understanding how the intervention operated in practice was critical to refining this theory and informing future scale-up. This paper presents a structured exemplar of theory refinement, addressing this recognised gap in implementation science. Methods: A deductive thematic analysis was conducted, using the logic model as a coding framework. We synthesised previously reported findings with new qualitative insights from feasibility interviews, fieldnotes, supervision records and researcher reflections. Confirmed, refined, and newly emergent theoretical components were identified and the logic model updated. Results: Many original theory elements were confirmed, including improved review processes leading to enhanced care plan personalisation and staff training increasing confidence in care delivery. New mechanisms were identified, such as mapping local services as a relational tool and dementia review templates as educational resources. Pre-implementation activities, such as specific CDL training and champion identification, emerged as critical to success. Role ambiguity and capacity concerns acted as negative mechanisms, impeding implementation. These insights informed a revised logic model to guide future scale-up. Conclusions: This paper demonstrates the value of theory refinement following feasibility testing. By unpacking the ‘black box’ of implementation, we offer a transparent model for optimising complex interventions in primary care-led dementia support. Trial registration number ISRCTN11677384.
Author(s): Griffiths S, Spencer E, Robinson L, Rait G, Burns A, Evans E, King D, Knapp M, Lewins RD, Banerjee S, Manthorpe J, Allen L, Tucker S, Wittenberg R
Publication type: Article
Publication status: Published
Journal: PLoS One
Year: 2026
Volume: 21
Issue: 3
Online publication date: 17/03/2026
Acceptance date: 21/03/2026
Date deposited: 30/03/2026
ISSN (electronic): 1932-6203
Publisher: Public Library of Science
URL: https://doi.org/10.1371/journal.pone.0333154
DOI: 10.1371/journal.pone.0333154
Data Access Statement: Quantitative data are available from the authors upon reasonable request with permission of Professor Greta Rait (g.rait@ucl.ac.uk). Requests to use data will be submitted on a standard form and reviewed by a committee prior to data-sharing agreements being developed. Ethical approval for this study, as provided by Wales REC 4 of the National Research Ethics Service (21/WA/0267), prohibits us from sharing the full data. Pseudonymised excerpts of data relevant to the analysis have been provided within the paper. While ethical approval is in place to share excerpts of pseudonymised data within published works, the nature of the data mean that transcripts being made available in their entirety could risk participants becoming identifiable. Data being made available in this way would also violate the agreement to which participants consented. Queries relating to data access can be addressed to the Clinical Trials Unit of the UCL Research Department via priment@ucl.ac.uk.
Altmetrics provided by Altmetric
