Guideline development

This guideline has been produced using methodology to adopt and adapt recommendations from other high-quality guidelines.

A systematic search was carried out to identify guidelines published between 2019 and 2023, which were selected against the following criteria:

• research questions aligned to the remit of this guideline, and
• an evidence review that included primary literature.

Final screening was conducted by selecting the guidelines that scored highly (over 75%) when assessed using the items for rigour of development and editorial independence in the Appraisal of Guidelines Research and Evaluation (AGREE II) tool.

All relevant recommendations matching the key questions were extracted and themed. A final set of recommendations was shortlisted based on provision of non-overlapping advice. Recommendations from UK-based guidelines and more recently published guidelines were prioritised.

Using a modified Delphi approach, a multidisciplinary guideline development group addressed each recommendation to consider whether it could be adopted verbatim or adapted, based on:

• the applicability of the recommendation to NHSScotland, for example, alignment with SMC advice, financial, human and other resource implications
• the impact of the recommendation on people and carers with lived experience in Scotland, and issues identified in the EQIA.

Where a recommendation was evidence based but not considered applicable, the recommendation was not included, or the text was revised to better reflect Scottish practice. Changes were discussed and agreed by the guideline development group. No additional review for primary evidence was conducted.

Details of the evidence review and evidence-to-decision making for the original recommendations are available from the source guidelines. 

SIGN acknowledges and thanks NICE and Diabetes Canada for their generous agreement to use their guidelines as the basis of this work.

The guideline development group identified the following areas where there was insufficient research to support an evidence-based recommendation:

• how long before type 2 diabetes develops in those with prediabetes
• predictors for the development of type 2 diabetes in those at risk
• the effectiveness of automating a risk-assessment tool via patient record systems (eg Vision) in reducing variation in care or access to testing
• the effectiveness of non-dietary interventions and risk factors, such as smoking, for prevention and remission
• the effectiveness of psychological wellbeing support interventions for prevention, early management and remission
• the role of physical activity in the remission of type 2 diabetes
• the minimum and maximum ages at which BMS will help achieve remission of type 2 diabetes
• the association between duration of type 2 diabetes and benefit from BMS
• health benefits of reducing diabetes medication after surgery rather than achieving remission
• validation of holistic tools for assess an individual’s suitability for BMS
• the long-term complications of BMS.

This guideline was issued in 2025 and will be considered for review in three years. The review history, and any updates to the guideline in the interim period, will be noted in the update report, which is available in the supporting material section for this guideline on the SIGN website: www.sign.ac.uk

Comments on new evidence that would update this guideline are welcome and should be sent to sign@sign.ac.uk