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Interpreting the reasons for the choice and changing of two drug regimens in an observational cohort: comparison of a ritonavir‐boosted protease inhibitor‐based versus a nonnucleoside reverse transcriptase inhibitor‐based first‐line regimen
Author(s) -
Jarrin I,
HernándezNovoa B,
Alejos B,
Santos I,
LopezAldeguer J,
Riera M,
Gutiérrez F,
Rubio R,
Antela A,
Blanco JR,
Moreno S
Publication year - 2014
Publication title -
hiv medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.53
H-Index - 79
eISSN - 1468-1293
pISSN - 1464-2662
DOI - 10.1111/hiv.12144
Subject(s) - medicine , ritonavir , efavirenz , confidence interval , atazanavir , hazard ratio , lopinavir , regimen , abacavir , odds ratio , cohort , reverse transcriptase inhibitor , cohort study , logistic regression , viral load , immunology , human immunodeficiency virus (hiv) , antiretroviral therapy
Objectives We compared reasons for the choice of regimen, time to and reasons for third drug modification, virological response and change in CD4 T ‐cell counts in patients started on atazanavir/ritonavir ( ATV /r)‐ vs. efavirenz ( EFV )‐based first‐line regimens. Methods We included patients from the Cohort of the Spanish HIV Research Network ( CoRIS ), a multicentre cohort of HIV ‐positive treatment‐naïve subjects, in the study. We used logistic regression to assess factors associated with choosing ATV /r vs. EFV , proportional hazards models on the subdistribution hazard to estimate subdistribution hazard ratios ( sHRs ) for third drug modification, logistic regression to estimate odds ratios ( ORs ) for virological response and linear regression to assess mean differences in CD4 T ‐cell count increase from baseline. Results Of 2167 patients, 10.7% started on ATV /r. ATV /r was more likely than EFV to be prescribed in injecting drug users [adjusted OR 1.85; 95% confidence interval ( CI ) 1.03–3.33], in 2009–2010 (adjusted OR 1.63; 95% CI 1.08–2.47) and combined with abacavir plus lamivudine (adjusted OR 1.53; 95% CI 0.98–2.43). Multivariate analyses showed no differences, comparing ATV /r vs. EFV , in the risk of third drug modification ( sHR 1.04; 95% CI 0.74–1.46) or in virological response ( OR 0.81; 95% CI 0.46–1.41); differences in mean CD4 T ‐cell count increase from baseline were at the limit of statistical significance (mean difference 29.8 cells/μL; 95% CI −4.1 to 63.6 cells/μL). In patients changing from EFV , 48% of changes were attributable to toxicity/adverse events, 16% to treatment failure/resistance, 3% to simplification, and 8 and 12%, respectively, to patients' and physicians' decisions; these percentages were 24, 6, 12, 14 and 24%, respectively, in those changing from ATV /r. Conclusions ATV/r‐ and EFV‐based regimens meet the requirements of both efficacy and safety for initial combination antiretroviral regimen, which relate to better durability.