Monitoring of Antiretroviral Therapy in Resource-limited Settings
Background: As second-line antiretroviral therapy (ART) availability increases in resource-limited settings, questions about the value of laboratory monitoring remain. We assessed the outcomes and cost-effectiveness (CE) of laboratory monitoring to guide switching ART.
Methods: We used a computer model to project life expectancy and costs of different strategies to guide ART switching in patients in Côte d'Ivoire. Strategies included clinical assessment, CD4 count, and HIV RNA testing. Data were from clinical trials and cohort studies from Côte d'Ivoire and the literature. Outcomes were compared using the incremental CE ratio. We conducted multiple sensitivity analyses to assess uncertainty in model parameters.
Results: Compared with first-line ART only, second-line ART increased life expectancy by 24% with clinical monitoring only, 46% with CD4 monitoring, and 61% with HIV RNA monitoring. The incremental CE ratio of switching based on clinical monitoring was $1670 per year of life gained (YLS) compared with first-line ART only; biannual CD4 monitoring was $2120 per YLS. The CE ratio of biannual HIV RNA testing ranged from $2920 ($87/test) to $1990 per YLS ($25/test). If second-line ART costs were reduced, the CE of HIV RNA monitoring improved.
Conclusions: In resource-limited settings, CD4 count and HIV RNA monitoring to guide switching to second-line ART improve survival and, under most conditions, are cost-effective.
The past decade has seen unprecedented increases in access to and delivery of HIV treatment and care. Affordable and effective first-line antiretroviral regimens are now widely available, and an estimated 3 million people have started antiretroviral therapy (ART) in resource-limited settings. For those who need it, second-line ART is becoming increasingly affordable and accessible.
Although access to and delivery of HIV treatment have improved, resource constraints have curbed use of laboratory-based diagnostic tests in many developing countries and led to shifting attitudes toward what should be recommended in terms of patient monitoring. In 2006, the World Health Organization's (WHO's) public health response to HIV led to guidelines emphasizing a tiered patient monitoring structure, with CD4 count at the district level and CD4 count and HIV RNA quantification at the regional level but with neither considered compulsory for patient management. In 2008, based on results from a study by Phillips et al suggesting only modest clinical benefit from CD4 count or HIV RNA monitoring to guide switching to second-line ART, WHO emphasized the use of clinical monitoring. Whereas HIV RNA testing has been available in only limited settings, the decreasing costs and simplification of CD4 count technologies have allowed scale-up of immunologic monitoring in many developing countries. This led the WHO to reaffirm the importance of CD4 counts and to recommend in 2009 that clinical failure should be confirmed at least by immunological criteria when HIV RNA is not available.
In keeping with this recent recommendation, most current national guidelines consider CD4 counts along with clinical criteria as the standard of care for monitoring patients receiving ART, although virologic monitoring in these settings is still generally considered optional. In the context of a country like Côte d'Ivoire, a low-income West African country with adult HIV prevalence of approximately 3.9%, our objective was to examine the clinical benefits, costs, and cost-effectiveness (CE) of CD4 count and/or HIV RNA monitoring in guiding switching to second-line ART.
Abstract and Introduction
Abstract
Background: As second-line antiretroviral therapy (ART) availability increases in resource-limited settings, questions about the value of laboratory monitoring remain. We assessed the outcomes and cost-effectiveness (CE) of laboratory monitoring to guide switching ART.
Methods: We used a computer model to project life expectancy and costs of different strategies to guide ART switching in patients in Côte d'Ivoire. Strategies included clinical assessment, CD4 count, and HIV RNA testing. Data were from clinical trials and cohort studies from Côte d'Ivoire and the literature. Outcomes were compared using the incremental CE ratio. We conducted multiple sensitivity analyses to assess uncertainty in model parameters.
Results: Compared with first-line ART only, second-line ART increased life expectancy by 24% with clinical monitoring only, 46% with CD4 monitoring, and 61% with HIV RNA monitoring. The incremental CE ratio of switching based on clinical monitoring was $1670 per year of life gained (YLS) compared with first-line ART only; biannual CD4 monitoring was $2120 per YLS. The CE ratio of biannual HIV RNA testing ranged from $2920 ($87/test) to $1990 per YLS ($25/test). If second-line ART costs were reduced, the CE of HIV RNA monitoring improved.
Conclusions: In resource-limited settings, CD4 count and HIV RNA monitoring to guide switching to second-line ART improve survival and, under most conditions, are cost-effective.
Introduction
The past decade has seen unprecedented increases in access to and delivery of HIV treatment and care. Affordable and effective first-line antiretroviral regimens are now widely available, and an estimated 3 million people have started antiretroviral therapy (ART) in resource-limited settings. For those who need it, second-line ART is becoming increasingly affordable and accessible.
Although access to and delivery of HIV treatment have improved, resource constraints have curbed use of laboratory-based diagnostic tests in many developing countries and led to shifting attitudes toward what should be recommended in terms of patient monitoring. In 2006, the World Health Organization's (WHO's) public health response to HIV led to guidelines emphasizing a tiered patient monitoring structure, with CD4 count at the district level and CD4 count and HIV RNA quantification at the regional level but with neither considered compulsory for patient management. In 2008, based on results from a study by Phillips et al suggesting only modest clinical benefit from CD4 count or HIV RNA monitoring to guide switching to second-line ART, WHO emphasized the use of clinical monitoring. Whereas HIV RNA testing has been available in only limited settings, the decreasing costs and simplification of CD4 count technologies have allowed scale-up of immunologic monitoring in many developing countries. This led the WHO to reaffirm the importance of CD4 counts and to recommend in 2009 that clinical failure should be confirmed at least by immunological criteria when HIV RNA is not available.
In keeping with this recent recommendation, most current national guidelines consider CD4 counts along with clinical criteria as the standard of care for monitoring patients receiving ART, although virologic monitoring in these settings is still generally considered optional. In the context of a country like Côte d'Ivoire, a low-income West African country with adult HIV prevalence of approximately 3.9%, our objective was to examine the clinical benefits, costs, and cost-effectiveness (CE) of CD4 count and/or HIV RNA monitoring in guiding switching to second-line ART.
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