Objective: To describe the time from first viral rebound on highly active antiretroviral therapy to first treatment change, identify factors associated with more rapid switching, and investigate whether treatment changes are in line with treatment guidelines.
Design and setting: A multicentre cohort study.
Methods: We described the time to first treatment switch among individuals experiencing confirmed virological rebound after initiating highly active antiretroviral therapy; factors associated with more rapid switching were identified using proportional hazards regression and predictors of a switch in line with guidelines were identified using logistic regression.
Results: Thirty-four percent of the 694 patients experiencing virological rebound remained on a failing regimen for more than 6 months. Factors associated with more rapid switching were lower CD4 cell count (hazard ratio, 0.84 /100 cells/mul higher, P < 0.001), higher viral load (1.29 /log10 copies/ml higher, P < 0.001), older age (1.06 /5 years older, P = 0.07), and changing/adding drugs to the regimen prior to rebound (1.16, P = 0.16). Two hundred and eighteen of the 394 treatment changes (55%) were in line with guidelines; those receiving nonnucleoside reverse transcriptase inhibitor-containing regimens were more likely to make changes in line with guidelines (adjusted odds ratio, 2.80, P < 0.001), whereas those who had previously added drugs to their regimen were less likely to make changes in line with guidelines (0.15, P = 0.001).
Conclusion: A substantial minority of patients remain on a failing highly active antiretroviral therapy regimen for periods of 6 months or longer without adding new drugs. Changes made are often not in line with treatment guidelines, raising concerns about the development of resistance and long-term clinical outcomes in these individuals.