2.2. Study Design and Study Population

This observational cohort was conducted in the rural areas of Guangxi, in southwest China. The cohort profile and characteristics of this database have been previously described [8, 10, 16]. The data were collected from 2003 to 2015. The eligibility criteria for the participants were 18 years or older, HIV-positive patients, recipient of first-line ART at any point between 2003 and 2015, willingness, and those who provide written consent for the study. It has 64% of participants still in follow-up. The study was approved by the institutional review board of the Guangxi Center for Disease Control and Prevention (reference number for the ethics committee to this manuscript is GXIRB2016-0047).

Attrition was defined as a cessation of ART or loss to follow-up as recorded in the HIV treatment database [18]. Lost to follow-up was defined as missing more than 90 days after the last date seen in the clinic, which was also defined as the date of withdrawal [10, 12].