This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Articles www.thelancet.com Vol 371 April 26, 2008 1443 Outcomes from monitoring of patients on antiretroviral therapy in resource-limited settings with viral load, CD4 cell count, or clinical observation alone: a computer simulation model Andrew N Phillips, Deenan Pillay, Alec H Miners, Diane E Bennett, Charles F Gilks, Jens D Lundgren Summary Background In lower-income countries, WHO recommends a population-based approach to antiretroviral treatment with standardised regimens and clinical decision making based on clinical status and, where available CD4 cell count, rather than viral load. Our aim was to study the potential consequences of such monitoring strategies, especially in terms of survival and resistance development. Methods A validated computer simulation model of HIV infection and the e9 ect of antiretroviral therapy was used to compare survival, use of second-line regimens, and development of resistance that result from di9 erent strategies based on viral load, CD4 cell count, or clinical observation alonefor determining when to switch people starting antiretroviral treatment with the WHO-recommended fi rst-line regimen of stavudine, lamivudine, and nevirapine to second-line antiretroviral treatment. Findings Over 5 years, the predicted proportion of potential life-years survived was 83% with viral load monitoring (switch when viral load >500 copies per mL), 82% with CD4 cell count monitoring (switch at 50% drop from peak), and 82% with clinical monitoring (switch when two new WHO stage 3 events or a WHO stage 4 event occur). Corresponding values over 20 years were 67%, 64%, and 64%. Findings were robust to variations in model specifi cation in extensive univariable and multivariable sensitivity analyses. Although survival was slightly longer with viral load monitoring, this strategy was not the most cost e9 ective. Interpretation For patients on the fi rst-line regimen of stavudine, lamivudine, and nevirapine the benefi ts of viral load or CD4 cell count monitoring over clinical monitoring alone are modest. Development of cheap and robust versions of these assays is important, but widening access to antiretroviralswith or without laboratory monitoringis currently the highest priority. Funding None. Introduction For antiretroviral treatment to be introduced as widely and rapidly as possible in lower-income settings, initial treatment will inevitably be provided without monitoring of viral load and, in many cases, without monitoring of CD4 cell counts; furthermore, the role of resistance testing is likely to be in monitoring emergence of resistance patterns at a population level rather than for individualised care. If second-line regimens are to be available in these lower-income settings the decision of when to switch a patient from a fi rst to a second-line regimen will have to be based on incidence of new HIV-related clinical disease andif availableCD4 cell count changes, rather than on the basis of viral load (ie,...
View Full Document
This note was uploaded on 02/13/2011 for the course BIO 228 taught by Professor Murphy during the Fall '10 term at Gustavus.
- Fall '10