The BEF data include 7 claims components: inpatient, outpatient (ambulatory and outpatient care provided in a hospital facility), durable medical equipment, hospice, home health agency, skilled nursing facility, and carrier claims. After an initial evaluation of glaucoma claims in all the data sets, we used only the carrier data. Physician data reflect claims for service provided by physicians regardless of the location (eg, hospital, outpatient clinic, office) and capture nearly all incidents (>98%, based on our review of the data, which found that only 1.3% of claims for glaucoma surgeries during the observation period were from emergency departments, inpatient hospitalization, and nonoutpatient locations) of glaucoma surgical care each year. In addition, claims for physician services are consistently filed using Current Procedural Terminology (CPT) codes. This facilitates the analysis and minimizes potential errors introduced by coordinating across different coding systems (eg, International Classification of Diseases, Ninth Revision, Clinical Modificationprocedure codes). The BEF data were treated with appropriate integrity, security, and confidentiality, as detailed in the Data Use Agreement required by Centers for Medicare and Medicaid Services.