HSR Commentary: Linking VA and Non-VA Data to Address Important US Veteran Health Services Research Issues.

This commentary summarizes the methods and topics addressed in the special issue of HSR focused on linkage of United States Department of Veterans Affairs (VA) and non-VA datasets. The issue illustrates that researchers are increasingly linking diverse datasets as a valuable method for obtaining outcomes, treatments, and covariates to evaluate and examine health care delivery that includes non-VA services. The issue serves as a reference to VA and non-VA investigators alike who employ data linkage methods to address high-impact clinical and health policy evaluations that span different care systems and different datasets.