Comparación de tres estrategias de tamizaje para la prevención de la infección perinatal por VIH en Colombia: análisis de decisiones / A comparison of three screening strategies for prevention of perinatal HIV infection in Colombia: a decision analysis model

OBJETIVO: Comparar mediante un modelo de análisis de decisiones tres estrategias de tamizaje de la infección por el VIH en mujeres embarazadas según su relación costo-efectividad y proponer la más apropiada para el sistema de salud colombiano. MÉTODOS: Estudio económico basado en el análisis mediante árboles de decisión según tres estrategias de tamizaje de la infección por el VIH en mujeres embarazadas: la voluntaria, la universal y la opcional. Se consideró a todas las mujeres colombianas embarazadas sin diagnóstico de infección por el VIH que se presentaban para el parto. Se emplearon los costos médicos directos desde la realización de la prueba hasta un año después del parto, según el Sistema General de Seguridad Social en Salud. Se compararon las razones costo-efectividad y el ahorro de cada estrategia analizada. RESULTADOS: Por cada 10 000 mujeres, la estrategia universal permitió detectar 5 casos más que la estrategia voluntaria y 7 casos más que la opcional. La estrategia universal generó costos aproximados de US$ 17,00 por cada recién nacido positivo, es decir, menos de la mitad que lo calculado para la estrategia voluntaria (US$ 38,00) y menor que para la opcional (US$ 24,00). Según el análisis bifactorial, la estrategia de tamizaje universal fue menos costosa que la voluntaria y más efectiva que las otras dos estrategias, independientemente de la prevalencia, la tasa de positivos falsos del sistema de diagnóstico empleado y la tasa de aceptación materna para realizarse la prueba de tamizaje. CONCLUSIONES: La estrategia de tamizaje voluntaria, que se utiliza actualmente en Colombia, es más costosa que la universal a mediano y largo plazos y tiene menor efectividad y capacidad de prevención. Se recomienda a las autoridades nacionales de salud realizar el tamizaje de la infección por el VIH a todas las embarazadas colombianas con pruebas de tercera generación.

OBJECTIVES: To apply decision analysis to compare the cost-effectiveness of three strategies for HIV screening of pregnant women and to recommend the one most appropriate for the health care system of Colombia. METHODS: An economic study applying decision analysis to three types of HIV screening of expectant women: voluntary, universal, and optional. All the women in Colombia with unknown HIV status who were admitted for child birth were included. The study included all the direct medical costs incurred from the time of testing through the first year following delivery, according to the General System for Healthcare Social Security. Cost-effectiveness ratio and the savings of each of the strategies were compared. RESULTS: For every 10 000 women, the universal strategy detected five cases more than the voluntary strategy and seven cases more than the optional. The universal strategy carried a cost of approximately US$ 17 for each HIV-positive newborn; that is, less than half of that of the voluntary strategy (US$ 38) and less than the optional (US$ 24). According to the bifactorial analysis, the universal screening strategy was less costly than the voluntary and more effective than both of the others, regardless of prevalence, the false-positive rate of each method, and the rate of maternal compliance with screening. CONCLUSIONS: The screening strategy currently in use in Colombia is more costly (in both the medium- and long-term), less effective, and less capable of prevention, than the universal screening strategy. The recommendation to the national health authorities of Colombia is to begin screening all pregnant women for HIV infection using third-generation testing.

Cost and efficiency of HIV voluntary counselling and testing centres in Andhra Pradesh, India.

BACKGROUND: [corrected] As part of the effort to control HIV/AIDS, the number of HlV voluntarycounselling and testingcentres (VCTCs) is increasing rapidly in the public health system of the Indian state of Andhra Pradesh, which is estimated to have one of the highest rates of HIV infection in India. However, systematic data on the cost and efficiency of providing VCT services in India are not available to help guide efficient use of resources for these services. METHODS: We used standardized methods to obtain detailed cost and output data for the 2002-03 fiscal year from written records and interviews in 17 VCTCs in the public health system in Andhra Pradesh. We calculated the economic cost per client receiving VCT services, and analysed the variation and determinants of total and unit costs across VCTCs. We used multivariate regression techniques to estimate incremental unit costs. We assessed hurdles towards serving an optimal number of clients by VCTCs. RESULTS: In the 2002-03 fiscal year, 32 413 clients received the complete sequence of services at the 17 VCTCs, including post-HIV test counselling. The number of clients served by each VCTC ranged from 334 to 7802 (median 979). The overall HIV-positive rate in post-test counselled clients was 20.5% (range 5.4%-52.6%). The cost per client for the complete VCT sequence varied 6-fold between VCTCs (range Rs 141.5-829.6 [US 2.92-17.14 dollars], median Rs 363.5 [US 7.51 dollars]). The cost per client was significantly lower at VCTCs with more clients (p < 0.001, R2 = 0.83; power function) due to substantial fixed costs. Personnel made up the largest component of cost (53.7%). The cost per client had a significant direct relation with percent personnel cost for VCTCs (p < 0.001, R2 = 0.58; exponential function). A multiple regression model revealed that the incremental cost of providing complete VCT services to each HIV-positive and -negative client was Rs 123.5 (US 2.54 dollars) and Rs 59.2 (US 1.22 dollars), respectively. Fourteen VCTCs (82.4%) reported that they could serve more clients with the available personnel and infrastructure, and that inadequate demand for their services was the main hurdle towards achieving this. CONCLUSION: These data suggest that the efforts of the National AIDS Control Organisation of India and the Andhra Pradesh State AIDS Control Society in increasing VCTCs could yield even higher benefit if the demand for these services was enhanced, as this would increase the number of clients served and reduce the cost per client. Ongoing systematic cost-efficiency analysis is necessary to help guide efficient use of HIV-control resources in India.