The aim of the systematic review was to describe the most recent guideline update processes, including up-to-date prioritisation methods, used by international or national groups who provide methods guidance for developing and updating clinical guidelines. The systematic review focused on updating processes for existing guidelines. This will support the NCEC in considering amendments to the current update processes outlined in their current methodological guidance.

In 2025, the CICER team conducted a follow-on rapid scoping review to describe criteria and processes internationally for retiring clinical guidelines.

The role of the National Clinical Effectiveness Committee (NCEC) is to prioritise and quality assure National Clinical Guidelines in Ireland. As such, the NCEC provides methodological guidance for guideline developers.

Ongoing evolution of the scientific literature brings new clinical evidence, which can change the recommendations made within a clinical guideline. As such, clinical guidelines need to be updated regularly to ensure the validity of their recommendations. The evolution of the scientific literature also brings advancement in the methodologies used to develop and update clinical guidelines. As such, methodological guidance relating to clinical guideline development should also be updated regularly to ensure it reflects the most up-to-date guideline development methods.

To support the NCEC, the CICER team independently reviews evidence and provides scientific support for the development of National Clinical Guidelines, by Guideline Development Groups.

The protocol sets out the steps planned for the systematic review on guideline update processes, including search strategies, screening, data extraction, quality appraisal, and synthesis. The follow-on scoping review on retiring guidelines contains additional information on its methodology.