Objective To identify the relevant prescribing quality domains of type 2 diabetes mellitus care as a basis for the selection of a minimal set of prescribing quality indicators from a set of previously validated indicators. Methods We used the principal factor analysis to identify the underlying dimensions or domains of prescribing quality for 76 general practitioners participating to the Groningen Initiative to Analyse Type 2 Diabetes Treatment project in the Netherlands. From a set of 10 prescribing quality indicators covering various aspects of cardiovascular and metabolic management, we selected a subset of indicators with the highest loading within each identified domain. Next, we evaluated the effect of using this subset on the quintil...