Understanding the role of qualitative evidence synthesis in health and social care guideline development: perspectives from guideline committee members and technical staff in a leading UK producer of health and social care guidelines.

This paper explores the perceptions and experiences of guideline committee members and technical staff at the UK's National Institute for Health and Care Excellence (NICE) regarding the use of qualitative evidence syntheses (QES) in the guideline development process. While QES has the potential to enrich guideline development with insights into service user experiences, implementation contexts, and social determinants of health, its integration into the process remains inconsistent. Drawing on 12 semi-structured interviews conducted with members from clinical, public health, and social care committees, and NICE technical staff, this qualitative study aimed to identify factors influencing the committees' use of QES in making guideline recommendations. Detailed analysis of the data identified three recurring themes: (1) trust in the credibility and robustness of QES; (2) challenges in the presentation and comprehension of QES; and (3) perceived value and limitations of QES in decision-making. Participants described uncertainty about qualitative methodologies, a reliance on the quantitative hierarchy of evidence, and variability in the quality and clarity of QES reporting. Despite these concerns, many saw QES as vital in amplifying service user voices and supporting lay-member engagement. The findings underscore the need for improved methodological transparency, clearer integration of qualitative and quantitative evidence, and capacity building in QES methods. This study contributes to the literature on evidence-informed policy and practice, highlighting key challenges and offering practical recommendations for enhancing the role of QES in guideline development.