Adherence is one of the main predictors of antiretroviral treatment success. A governmental initiative was launched in 1998 for HIV-infected patients in Senegal to provide access to highly active antiretroviral therapy.
Between August 1998 and April 2002, 404 adult patients were enrolled. Adherence measurements, defined as pills taken/pills prescribed, were assessed between November 1999 and April 2009 using a pill count along with a questionnaire for 330 patients. Predictors of adherence were explored through a random-intercept Tobit model and a latent class analysis (LCA) was performed to identify adherence trajectories. We also performed a survival analysis taking into account gender and latent adherence classes.
Median treatment duration was 91 months (interquartile range, 84-101). On average, adherence declined by 7% every year, was 30% lower for patients taking indinavir, and 12% higher for those receiving cotrimoxazole prophylaxis. Based on the predicted probability of having an adherence ≥ 95%, LCA revealed 3 adherence behaviors and a better adherence for women. A quarter of patients had a high adherence trajectory over time and half had an intermediate one. Male gender and low adherence behavior over time were independently associated with a higher mortality rate.
This study shows that an overall good adherence can be obtained in the long term in Senegal. LCA suggests a better adherence for women and points out a large subsample of patients with intermediate level of adherence behavior who are at risk for developing resistance to antiretroviral drugs. This study warrants further research into gender issues.
From the *Hospices Civils de Lyon, Service de Biostatistique, Lyon, France; †Université de Lyon, Lyon, France; ‡Université Lyon I, Villeurbanne, France; §CNRS UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique Santé, Pierre-Bénite, France; ‖Centre de Recherche et de Formation à la Prise en Charge Clinique, Centre Hospitalier National Universitaire de Fann, Dakar, Sénégal; and ¶UMI 233, Institut de Recherche pour le Développement, Université Montpellier 1, Montpellier, France.
Received for publication September 30, 2010; accepted January 20, 2011.
Supported by the Agence Nationale de Recherche sur le Sida et les hépatites virales (ANRS, France) and by the Institut de Recherche pour le Développement (IRD, France).
Presented partly at the 5th International Francophone Conference on HIV/AIDS, March 28-31, 2010, Casablanca, Morocco.
The authors have no conflicts of interest to disclose.
Correspondence to: Mathieu Bastard, MSc, Epicentre, 8 rue Saint-Sabin, 75011 Paris, France (e-mail: firstname.lastname@example.org).