Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Flowchart for search and selection strategy for studies in the meta-analysis of CD4 cell count at virologic treatment failure and at time of switch to second-line ART in Sub-Saharan Africa. Abbreviations: ART, antiretroviral therapy; VL, viral load.
