Objective: We conducted a study to evaluate the sensitivity and specificity of using CD4+ measurement and clinical evaluation to detect antiretroviral treatment failure in HIV-infected patients who had received their first regimen of highly active antiretroviral therapy (HAART). The secondary objective was to determine the prevalence and risk factors of virological failure.
Methods: A retrospective cohort study was conducted at Chiang Mai University Hospital, Thailand. Univariate analysis was performed to compare risk ratios between patients with and without virological failure. Sensitivity and specificity of the immunological and/or clinical criteria in comparison with virological criteria were calculated using 2 by 2 tables.
Results: From January 2003 to December 2005, 327 HIV-infected patients were enrolled. The median follow-up period was 19 months (range 6-42 months). Virological failure was detected in 9.2% of patients. Patients with a previous history of opportunistic infection had a greater risk for developing virological failure (OR=2.66, 95% CI=1.1-6.4). Using the combined immunological and clinical criteria to detect antiretroviral treatment failure, the sensitivity was 20.0% and the specificity was 85.9%.
Conclusions: Our study, which was limited by small numbers, was not able to demonstrate that immunological or clinical criteria can adequately replace virological criteria for the determination of treatment failure.