The Guideline Assessment Project is a tripartite project that aims to develop an evidence-based and consensus-informed AGREE II Extension for Surgical Guidelines.
Aim of GAP II
Aim of GAP II was to explore how items within each AGREE II domain were interrelated, with the objective to calibrate the AGREE II instrument for use in surgical guidelines, to provide suggestions to refine the AGREE II instrument and thereby better meet the requirements for clinical practice guidelines in surgery.
What we did
We employed a series of statistical methods to explore reliability and internal consistency of the AGREE II instrument. We investigated the internal consistency that refers to the extent to which all items of the instrument measure the same hypothetical construct. We explored if and how test items are intercorrelated.
What we used
Using reliability analysis, Kendall’s tau statistics, factor analysis and the item response theory, we explored whether items of each AGREE II domain are intercorrelated and are, therefore, indicators of the same construct. We have finally drafted a modified AGREE II document on the basis of the outcomes of statistical models.