OBJECTIVES : During the last few years, there has been an increasing trend in switching antiretroviral (ART) therapy in Colombia. The Colombian HIV Group (VIHCOL) gathers data from both private and public HIV clinics around the country. We aimed to describe sociodemographic and clinical characteristics of HIV patients who switched ART treatment and to identify the main causes that led to ART switch.

METHODS : A multicentric retrospective cohort study was conducted among 15 VIHCOL clinics in Colombia. We included patients aged ≥ 18 years who switched ART from January 2017 to December 2019. Descriptive statistics were used to summarize demographic and clinical information. Additionally, bivariate correlation analysis between patients with one switch and ≥ 2 switches were performed.

RESULTS : A total of 554 patients switched ART during the study period, 79.8% (442/554) were men and the median age was 38 years (IQR: 29-52). 78.3% (434/554) presented only one regimen switch. The main cause of ART switch was tolerability (n=341; 61.6%) followed by virological failure (n= 89; 16.1%). During the follow up period, 33% (184/554), 39% (220/554) and 27% (150/554) switched ART in the first, second and third year, respectively. No differences were found regarding patient stage of disease (according to CDC classification system of HIV), virological response, cause of switching, and mortality when comparing patient with one switch versus those who presented two or more switches.

CONCLUSIONS : In this Colombian PLWHIV study, the principal cause for switching ART was tolerability; thus, questioning the election of the initial ART regimen which needs to not only be virologically effective, but also have a safe adverse event profile. This is a preliminary result of an ongoing study which plans to evaluate with a survival analysis the differences between causes of ART switch.