To ensure adequate follow-up time, we identified subjects who initiated their first course of cART in the VA between 1 January 1997 and 1 August 2002. We used pharmacy data to identify individuals initiating a minimum of three antiretroviral medications and laboratory data to determine that they had received a minimal evaluation (CD4 cell count, HIV-RNA and haemoglobin) within 6 months of initiating cART.
Available data included demographic factors (age, race/ethnicity and gender), administrative diagnostic codes [International Statistical Classification of Diseases and Related Health Problems (ICD)-9 codes], routinely collected clinical laboratory data, pharmacy data and long-term mortality. All laboratory data were collected from the clinical sites through the Immunology Case Registry [26 (link)]. Pharmacy data are drawn from the national VA Pharmacy Benefits Management Package [27 ]. ICD-9 codes were used to determine diagnoses of drug abuse or dependence, alcohol abuse or dependence, and AIDS-defining illnesses. Hepatitis C was defined as a positive antibody, qualitative or quantitative HIV RNA, or ICD-9 codes. Hepatitis B was defined as a positive surface antigen test or ICD-9 codes. In all cases in which ICD-9 codes were used, two out-patient or one in-patient code was required before the condition was considered present. This approach improves the accuracy of ICD-9 codes when compared with chart review [28 (link)]. The specific codes used can be found at our website (http://VAcohort.org ). All cause mortality data using VA data sources have been demonstrated to be accurate and complete when compared with the National Death Registry [29 (link),30 (link)].
Available data included demographic factors (age, race/ethnicity and gender), administrative diagnostic codes [International Statistical Classification of Diseases and Related Health Problems (ICD)-9 codes], routinely collected clinical laboratory data, pharmacy data and long-term mortality. All laboratory data were collected from the clinical sites through the Immunology Case Registry [26 (link)]. Pharmacy data are drawn from the national VA Pharmacy Benefits Management Package [27 ]. ICD-9 codes were used to determine diagnoses of drug abuse or dependence, alcohol abuse or dependence, and AIDS-defining illnesses. Hepatitis C was defined as a positive antibody, qualitative or quantitative HIV RNA, or ICD-9 codes. Hepatitis B was defined as a positive surface antigen test or ICD-9 codes. In all cases in which ICD-9 codes were used, two out-patient or one in-patient code was required before the condition was considered present. This approach improves the accuracy of ICD-9 codes when compared with chart review [28 (link)]. The specific codes used can be found at our website (
