“…The probable reason is the difference in patient conditions, co-morbid situation or contraindications. Like several other studies (D'Arminio et al, 2000;Dorrucci et al, 2001;Mocroft et al, 2001;O'Brien et al, 2003;Kumara & Vallabhaneni, 2006;Kiguba, 2007;Hart, 2007;Cesar et al, 2010), the most known causes of ARV switching, in the present study, was toxicity with significant heterogeneity in the distribution of adverse events, which is also statistically significant. The patients were with more advanced disease at baseline, which may necessitates higher rates of regimen change/discontinuation due to adverse events.…”