Occurence and determinants of treatment faiure in antiretroviral therapy at Tshwane District Hospital
Date
2012-03
Authors
Sokoya, Temitope
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Objective: To determine the proportion of HIV+ patients who fail treatment on a
yearly basis in a 5-year treatment cohort in Tshwane District Hospital and to
determine the correlation of treatment failure with variables routinely measured at the
clinic namely WHO stage, CD4 count, HIV viral load, age, gender, presence of
concomitant diseases, concomitant medication and distance travelled to clinic.
Design: A retrospective study with an analytical component was conducted using the
hospital records of adult patients receiving antiretroviral therapy in 2004 and followed
for 5 years (until 2009) at the Tshwane District Hospital.
Methods: All adult patients receiving antiretroviral therapy in 2004 were identified
and followed for the next 5 years till 2009 at Tshwane District Hospital. The
proportion of patients that failed treatment yearly was calculated. Univariate analysis
was used to compare all patients who failed at any time point with the patients who
did not fail at all for all variables. A repeated measures logistic regression model was
developed to determine the variables that impacted on the binary outcome, namely
treatment failure or not.
Results: Of the 1104 adult patients who were attending the TDH Immunology clinic
in 2004, 870 adults were receiving ARVs. 333 patients (38.28 %) experienced
treatment failure throughout the study period. 6.9 % (60/870) of the study population
failed virologically. 307 of the 870 patients (35.29 %) failed treatment
immunologically. 102 patients (11.72 %) experience treatment failure at the 12 month
time point, 37 patients(4.49 %) at the 24 month time point, 57 patients(6.93 %) at 36
month time point, 101 patients(12.27 %) at the 48 month time point and 140 patients
(7.01 %) failed treatment at 60 month time point. Univariate analysis showed
significant correlation between treatment failure and non-adherer, interrupting
treatment, defaulted treatment, viral load at baseline, 12, 24, 36, 48, 60 months, and
CD4 count at baseline, 12, 24, 36, 48, 60 months. In the multivariate analysis, there
was a significant association between short term stoppage of treatment (STSTOP)
(coefficient ratio = 1.41; p<0.001), long term stoppage of treatment (LTSTOP)
(coefficient ratio = 3.24; p<0.001), transfers from other health institutions (coefficient
ratio = 1.96; p<0.001), regimen (coefficient ratio = -0.1734) and treatment failure. The
change in log viral load at 12 months from baseline (LOGVLBL12) (coefficient ratio
=-1.7145; p<0.001) was highly significant for reaching the end point - treatment
v
failure. Older patients were less likely to fail treatment (coefficient ratio = -0.0517,
p<0.001) and patients with an advance stage of the disease (WHO stage 3 or 4)
were at a lower risk of failing treatment (coefficient ratio = -0.4175; P=0.008). The
CD4 count was significant in the univariate analysis P<0.01) and XTGEE (coefficient
ratio =- 0.0001; p<0.001). There was no significant correlation between gender, place
of residence, employment status and treatment failure.
Conclusion: More than one–third of the patients receiving treatment in TDH failed
treatment within the 5 year study period. The determinants of treatment failure are
age, WHO stage, transfer from other institutions, short term stoppage of treatment,
long term stoppage of treatment, CD4 cell count and the level of viral suppression
within the first year of treatment (LOGVLBL-12). This study reinforces the need for
identifying high risk patients earlier in treatment in order to implement strategies that
might strengthen adherence to treatment.
Description
A research report submitted to the Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of
Master of Science in Pharmaceutical Affairs
Johannesburg, 2012