Differences and risk factors of regimen modification in acquired immunodeficiency syndrome patients who initiated antiretroviral treatment

Abstract

Objective To compare the rates of regimen modification between patients with different initial antiretroviral therapy, and to investigate risk factors associated with drug toxicity-related regimen modification. Methods A two-years retrospective cohort study was conducted in 14 060 patients who initiated antiretroviral treatment with Zidovudine (AZT)/Tenofovir disoproxil (TDF)+ Lamivudine (3TC)+ Efavirenz (EFV) since 2012. There were 5 126 patients initiated TDF+ 3TC+ EFV therapy (TDF group) and 8 934 patients initiated AZT+ 3TC+ EFV therapy (AZT group). Chi-square test was used to compare the rate of first-line regimen modification and the rate of toxicity-related regimen modification between two groups. Cox proportional hazard model was used to investigate the risk factors associated with regimen modification. Results A total of 14 060 acquired immunodeficiency syndrome patients were observed for a median period of 1.85 person-years. There were 2 795 patients who changed their initial antiretroviral regimen and the rate of initial regimen modification was 19.9%. Two hundred patients who changed their initial regimen due to pregnancy were excluded. There were 2 070 patients in AZT group who changed their initial regimen with a rate of 23.5%. Among them, 1 652 patients changed their regimen due to drug toxicity and the rate was 18.8%. There were 525 patients in TDF group who changed their initial regimen with a rate of 10.4% and the rate of toxicity-related regimen modification was 6.2%. The differences between two groups were statistical significance (χ2=366.68 and 416.89, respectively, both P<0.01). The risk of regimen modification in AZT group were significantly higher than that in TDF group (aHR=2.89, 95%CI: 2.57-3.24). The risk of toxicity-related regimen modification in AZT group was also significantly higher than that in TDF group (aHR=3.85, 95%CI: 3.34-4.45). Conclusions Patients initiated antiretroviral treatment with AZT+ 3TC+ EFV are more likely to change their initial regimen than those who initiated treatment with TDF+ 3TC+ EFV. Female, age >45 years old, BMI<18.5 kg/cm2 and baseline CD4+ T cell count<200/L were risk factors associated with regimen modification. Key words: Acquired immunodeficiency syndrome; Antiretroviral therapy; Regimen change; Drug side effects; Tenofovir