Implementation and Operational Research: Risk Charts to Guide Targeted HIV-1 Viral Load Monitoring of ART: Development and Validation in Patients From Resource-Limited Settings.

BACKGROUND HIV-1 RNA viral load (VL) testing is recommended to monitor antiretroviral therapy (ART) but not available in many resource-limited settings. We developed and validated CD4-based risk charts to guide targeted VL testing. METHODS We modeled the probability of virologic failure up to 5 years of ART based on current and baseline CD4 counts, developed decision rules for targeted VL testing of 10%, 20%, or 40% of patients in 7 cohorts of patients starting ART in South Africa, and plotted cutoffs for VL testing on colour-coded risk charts. We assessed the accuracy of risk chart-guided VL testing to detect virologic failure in validation cohorts from South Africa, Zambia, and the Asia-Pacific. RESULTS In total, 31,450 adult patients were included in the derivation and 25,294 patients in the validation cohorts. Positive predictive values increased with the percentage of patients tested: from 79% (10% tested) to 98% (40% tested) in the South African cohort, from 64% to 93% in the Zambian cohort, and from 73% to 96% in the Asia-Pacific cohort. Corresponding increases in sensitivity were from 35% to 68% in South Africa, from 55% to 82% in Zambia, and from 37% to 71% in Asia-Pacific. The area under the receiver operating curve increased from 0.75 to 0.91 in South Africa, from 0.76 to 0.91 in Zambia, and from 0.77 to 0.92 in Asia-Pacific. CONCLUSIONS CD4-based risk charts with optimal cutoffs for targeted VL testing maybe useful to monitor ART in settings where VL capacity is limited.

Energy from the West : a progress report of a technology assessment of western energy resource development : executive summary : prepared for Office of Research and Development, Environmental Protection Agency /

"Contract no. 68-01-1916."

Municipal solid waste, resource recovery : proceedings of the seventh annual research symposium at Philadelphia, Pennsylvania, March 16-18, 1981, by the U.S. EPA Office of Research & Development, Municipal Environmental Research Laboratory, Solid and Hazardous Waste Research Division /

Mode of access: Internet.

First year work plan for a technology assessment of Western energy resource development /

Mode of access: Internet.

Annotated bibliography of shore erosion and related physical materials concerning Wisconsin's Great Lakes coastal areas.

"Compiled through the ... efforts of James Stark"--p. 1.

Extension training around the world; handbook. In cooperation with Agency for International Development, U. S. Dept. of State.

Cover title.

Wisconsin Library network plan report : recommendations for network development at the area level /

WI docs. no: Ed.3/2:2250

Water-resource development: the economics of project evaluation.

Mode of access: Internet.

School forests in Wisconsin : a report on the 1999 statewide survey of Wisconsin's school forest coordinators /

"PUB-FR-159 2001"--Cover.

Guidelines for the establishment of WECEP programs in Wisconsin.

Mode of access: Internet.

Flood control and related surface water resource development in Jamaica : report prepared for the Government of Jamaica /

"54-00438 - 555"--Cover.

La Moine River basin study : a comprehensive plan for water resource development /

Bibliography: p. 57-59.

Zoning; an aid to community resource development

Bibliography: p. 14.