Early adherence to antiretroviral medication as a predictor of long-term HIV virological suppression: five-year follow up of an observational cohort.
OBJECTIVE
Previous studies have demonstrated a cross-sectional relationship between antiretroviral adherence and HIV virological suppression. We assessed the predictive value of baseline adherence in determining long-term virological failure.


METHODS
We assessed baseline adherence via an adherence questionnaire between administered to all consenting patients attending antiretroviral clinics in Khayelitsha township, South Africa, between May 2002 and March 2004. Virological status was ascertained after five years of follow up and multivariate analysis used to model associations of baseline variables and medication adherence with time to viral suppression or failure.


RESULTS
Our adherence cohort comprised 207 patients, among whom 72% were female. Median age was 30 years and median CD4 count at initiation was 55 cells/mm(3). We found no statistically significant differences between baseline characteristics and early adherence groups. Multivariate analysis adjusting for baseline CD4 and age found that patients with suboptimal baseline adherence had a hazard ratio of 2.82 (95% CI 1.19-6.66, p = 0.018) for progression to virological failure compared to those whose baseline adherence was considered optimal.


CONCLUSIONS
Our longitudinal study provides further confirmation of adherence as a primary determinant of subsequent confirmed virological failure, and serves as a reminder of the importance of initial early investments in adherence counseling and support as an effective way to maximize long-term treatment success.
Ford
Nathan
N
Médecins Sans Frontières, Cape Town, South Africa. nathan.ford@joburg.msf.org
Darder
Marta
M
Spelman
Tim
T
Maclean
Emi
E
Mills
Edward
E
Boulle
Andrew
A
D000328:Adult; D044966:Anti-Retroviral Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D055118:Medication Adherence; D016016:Proportional Hazards Models; D013997:Time Factors; D017211:Treatment Failure
D044966:Anti-Retroviral Agents