Development of an HIV research database using Medicaid claims data

The objective of this study was to develop an HIV research database from Medicaid claims data. A simple HIV case-finding algorithm that mirrors current practice was developed using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnosis codes, Current Procedural Terminology (CPT) codes for HIV-specific tests, and National Drug Codes (NDC) for antiretroviral medications. In total, 3,507 cases were identified: 3,217 (92 percent) of the cases were identifiable by ICD-9-CM diagnosis codes, 2,569 (73 percent) were identifiable by the drug codes, and 889 (25 percent) were identifiable by the testing codes. Of the cases selected by the diagnosis codes, 98 percent were selected by the ICD-9-CM codes for HIV/AIDS (042). Using the drug codes increased the yield by 8 percent over the number that were identifiable by diagnosis codes alone. Using this simple, updated methodology, most cases were identifiable by ICD-9-CM diagnosis codes, and, of those, 98 percent were identifiable by the codes for HIV/AIDS (042).