The Appraisal of Guidelines for Research and Evaluation (AGREE) II
Instrument14 was used to assess the methodological quality of the
guidelines. The 23-item instrument has been internationally validated
and consists of six domains: scope and purpose, stakeholder
involvement, rigour of development, clarity and presentation, applicability
and editorial independence. A definition of these domains
can be found in the Table S2. Each guideline was independently
appraised by PLV and AT. Each item within the six domains was
rated by allocating a value from 1 to 7 (1 = ‘Strongly Disagree’;