Incidence and predictors of first line antiretroviral regimen modification in western Kenya.
BACKGROUND
Limited antiretroviral treatment regimens in resource-limited settings require long-term sustainability of patients on the few available options. We evaluated the incidence and predictors of combined antiretroviral treatment (cART) modifications, in an outpatient cohort of 955 patients who initiated cART between January 2009 and January 2011 in western Kenya.


METHODS
cART modification was defined as either first time single drug substitution or switch. Incidence rates were determined by Poisson regression and risk factor analysis assessed using multivariate Cox regression modeling.


RESULTS
Over a median follow-up period of 10.7 months, 178 (18.7%) patients modified regimens (incidence rate (IR); 18.6 per 100 person years [95% CI: 16.2-21.8]). Toxicity was the most common cited reason (66.3%). In adjusted multivariate Cox piecewise regression model, WHO disease stage III/IV (aHR; 1.82, 95%CI: 1.25-2.66), stavudine (d4T) use (aHR; 2.21 95%CI: 1.49-3.30) and increase in age (aHR; 1.02, 95%CI: 1.0-1.04) were associated with increased risk of treatment modification within the first year post-cART. Zidovudine (AZT) and tenofovir (TDF) use had a reduced risk for modification (aHR; 0.60 95%CI: 0.38-0.96 and aHR; 0.51 95%CI: 0.29-0.91 respectively). Beyond one year of treatment, d4T use (aHR; 2.75, 95% CI: 1.25-6.05), baseline CD4 counts ≤350 cells/mm3 (aHR; 2.45, 95%CI: 1.14-5.26), increase in age (aHR; 1.05 95%CI: 1.02-1.07) and high baseline weight >60kg aHR; 2.69 95% CI: 1.58-4.59) were associated with risk of cART modification.


CONCLUSIONS
Early treatment initiation at higher CD4 counts and avoiding d4T use may reduce treatment modification and subsequently improve sustainability of patients on the available limited options.
Kenya Medical Research Institute, Kisumu, Kenya; Makerere University Medical School, Clinical Epidemiology Unit, Kampala, Uganda.
Seth
S
Inzaule
Jaramogi Oginga Odinga teaching and Referral Hospital, Kisumu, Kenya.
Juliana
J
Otieno
Makerere University Medical School, Clinical Epidemiology Unit, Kampala, Uganda.
Joan
J
Kalyango
Kenya Medical Research Institute, Kisumu, Kenya.
Lillian
L
Nafisa
Makerere University Medical School, Clinical Epidemiology Unit, Kampala, Uganda.
Charles
C
Kabugo
Makerere University Medical School, Clinical Epidemiology Unit, Kampala, Uganda.
Josephine
J
Nalusiba
Kenya Medical Research Institute, Kisumu, Kenya; US Centers for Disease Control and Prevention, HIV-Research Branch, Kisumu, Kenya.
Daniel
D
Kwaro
US Centers for Disease Control and Prevention, HIV-Research Branch, Kisumu, Kenya; Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
Clement
C
Zeh
Makerere University Medical School, Clinical Epidemiology Unit, Kampala, Uganda.
Charles
C
Karamagi
D000328:Adult; D000367:Age Factors; D044966:Anti-Retroviral Agents / Q000008:administration & dosage*; D018791:CD4 Lymphocyte Count; D004359:Drug Therapy, Combination / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology* / Q000276:immunology; D006801:Humans; D015994:Incidence; D007630:Kenya; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors
D044966:Anti-Retroviral Agents