ABSTRACT
This study explores the contribution of a single determination of plasma levels for measuring adherence by means of forecasting virologic failure. Adherence was measured by questionnaires, punctuality at appointments to withdraw drugs, and plasma levels. Virologic failure was considered when 2 detectable consecutive viral loads were observed in 2 consecutive determinations with at least 1 month between them. Univariant analysis, logistic regression, and receiver operating characteristic curves were carried out. In 29 cases, virologic failure was observed. The lowest incidence was found in patients considered adherent by plasma levels and highest in those who declared nonfulfillment. The combination of methods increased the association of the incidence of virologic failure with nonadherence. The use of questionnaires plus pharmacy information implies a gain in sensitivity and a slight loss of specificity. There is a high incidence of virologic failure in these patients and a strong link with their classification as nonadherent with methods such as questionnaires and pharmacy collection information. Plasma levels do not contribute much to the prediction of virologic failure.
Subject(s)
Antiretroviral Therapy, Highly Active , HIV Infections , HIV Infections/drug therapy , Humans , Prospective Studies , Viral LoadABSTRACT
INTRODUCCIÓN. Conocer la adherencia a los tratamientos antirretrovirales y las variables asociadas es de gran utilidad en el seguimiento de los pacientes infectados por el virus de la inmunodeficiencia humana (VIH). PACIENTES, MATERIAL Y MÉTODOS. Se han incluido todos los pacientes que acudieron a consultas externas de los Hospitales de León y el Bierzo entre enero y junio de 2000.Se consideraron no adherentes aquellos que manifestaron no haber ingerido en los 4 días previos a la entrevista el 10 por ciento o más del total de dosis prescritas de al menos un fármaco, o aquellos que en los últimos 3 meses habían acumulado un retraso en la recogida de los fármacos superior a 9 días. Se llevó a cabo un análisis de regresión logística con las variables asociadas a nivel univariado con la adherencia. RESULTADOS. Los métodos utilizados para medir la adherencia presentaron un índice kappa de 12,6 por ciento. De los 206 pacientes entrevistados se consideraron no adherentes 108 (52,4 por ciento; intervalo de confianza [IC] al 95 por ciento 45,6-59,2). Tras el análisis multivariado presentaban una significativa menor adherencia quienes refirieron haber consumido cocaína en los últimos 6 meses (odds ratio [OR] ajustada 5,1), no estar totalmente seguros de poder tomar correctamente los tratamientos prescritos (OR ajustada 2,5), y quienes no tenían prescritos la combinación de análogos zidovudina (AZT) y lamivudina (OR ajustada 1,9). Más de una tercera parte de los pacientes sin ninguna variable asociada a la no adhesión fueron considerados no adherentes. CONCLUSIÓN. La medida de la adherencia y sus predictores presenta importantes dificultades metodológicas. Con los criterios utilizados más de la mitad de los pacientes se consideraron no adherentes. Las variables asociadas a una baja adhesión son susceptibles de ser modificadas mediante intervenciones socio-psicosanitarias (AU)
Subject(s)
Humans , Sensitivity and Specificity , Spain , HIV Infections , Zidovudine , Treatment Refusal , Drug Utilization Review , Lamivudine , Anti-HIV Agents , Patient Compliance , Outpatient Clinics, Hospital , Registries , Antiretroviral Therapy, Highly Active , Data Collection , Drug Combinations , Patient DropoutsABSTRACT
INTRODUCTION: Knowledge of adherence to highly active antiretroviral treatment (HAART) and the variables associated with poor compliance is useful for the follow-up of HIV infected patients. PATIENTS, MATERIAL AND METHODS: Patients were consecutively recruited from the HIV outpatient clinics of the Hospitals of Leon and El Bierzo from January to June 2000. Patients were considered non-adherent to treatment if they failed to take 10% or more of their prescribed total dose of at least one drug during the 4 days before the interview, or if they had accumulated a delay of more than 9 days over the previous 3 months in picking up their prescribed drugs from the hospital pharmacy. Logistic regression analysis was performed with variables found to be associated with adherence in the univariate analysis. RESULTS: The methods used to determine adherence had a Kappa index of 12.6%. Among the 206 patients interviewed, 108 were considered non-adherent (52.4%; CI 95% 5 45.6-59.2). Multivariate analysis showed that the following factors were associated with poor treatment adherence: cocaine consumption in the previous six months (adjusted OR 5 5.1); patients unsure about the proper way to take prescribed treatment; (adjusted OR 5 2.5); and patients not prescribed the zidovudine-lamivudine combination (adjusted OR 5 1.9). Over one-third of patients with no variable associated with treatment adherence were considered non-compliant. CONCLUSION: Measurement of medication adherence and its predictive factors involved methodological difficulties. With the criteria used in the present study more than half the patients were considered non-compliant. The variables found to be related to poor adherence can be modified by social, psychological or health care interventions.
