Follow-up of the MCP-1/CCL2 Protein Synonyms Patients who did not stop or NRG1-beta 1 Protein custom synthesis switch was censored at the death date, date of moving out of British Columbia, date of entering a placebo trial, date of starting IP-10/CRG-2/CXCL10 Protein Species supervised therapy interruption, 30 September 2011 (study end date) or 3 years from ART start date, whichever came first. Variables that were significant at P<0.05 in the unadjusted analyses were candidates for inclusion in the multivariate model. A confounder model was fitted for era using the methods of Maldonado and Greenland.16 All analyses were PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25818165?dopt=Abstract performed using SAS software PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/25788415?dopt=Abstract version 9.3 (SAS Institute, Cary, NC, USA). Ethics statement This study was approved by the Committee on Human Research and the University of British Columbia/Providence Health Care Research Ethics Board.CIHR Author Manuscript CIHR Author Manuscript CIHR Author Manuscript ResultsA total of 7901 patients were included in the study. The median age was 39 years (IQR 33?46 years) and 83 were male. The median CD4 cell count at ART initiation was 220 cells/mm3 (IQR 110?50 cells/mm3) and the median HIV RNA was 4.9 log10 copies/mL (IQR 4.4?.0 log10 copies/mL). A total of 1855 patients (23.5 ) started treatment in preHAART era, 2406 patients (30.5 ) in 1996?000, 1533 patients (19.4 ) in 2001?5 and 2107 patients (26.7 ) in 2006?0. Patients‘ characteristics at baseline stratified by era of treatment are listed in Table 1, where all characteristics were statistically different (P<0.001). Due to the missing values for ethnicity, risk status and HCV, these variables were not included in the statistical model and are only explored in Table 1. All analyses involving viral load characteristics were limited to the HAART eras (n=6046), because in the preJ Antimicrob Chemother. Author manuscript; available in PMC 2015 September 25.Gonzalez-Serna et al.PageHAART era (n =1855) viral loads were not available in most patients, and comparisons of discontinuation based on virological suppression were limited to the mid-HAART and late HAART eras (n=3640).CIHR Author Manuscript CIHR Author Manuscript CIHR Author ManuscriptOverall, 5490 (69.5 ) patients discontinued therapy during follow-up, of whom 3659 (66.6 ) were switches and 1831 (33.4 ) were stops. The probability of discontinuation at 12, 24 and 36 months was 0.52 (95 CI 0.51?.53), 0.67 (95 CI 0.66?.69) and 0.76 (95 CI 0.75 ?.77), respectively (Figure 1a). At 36 months, the probability of switching was higher than that of stopping (0.64 versus 0.23). Based on eras, the probability of discontinuation at 36 months was progressively lower the more recent the era (0.94 in 1992?96, 0.78 in 1996?000, 0.77 in 2001?5 and 0.53 in 2006?0, P<0.001) (Figure 1b). Discontinuation rates in relation to the ART regimen showed that two NRTIs+NNRTI had a lower risk of discontinuation than two NRTIs+boosted or unboosted PI, or other combinations (P<0.001) (Figure 1c).