Fig. 5.

Hazard ratio for switching of each anchor drug class stratified by backbone and AIDS-defining illness. NNRTI: non-nucleoside reverse transcriptase inhibitor, PI: protease inhibitor, INSTI: integrase strand transfer inhibitor, TDF: tenofovir disoproxil fumarate, ABC: abacavir, CI: confidence interval. Six variables, including the type of backbone, anchor drug class, AIDS-defining illness, initiation year (2011–2013 or 2014–2016), and two interaction terms (between anchor drug class and AIDS-defining illness and between anchor drug class and type of backbone) were selected in the Cox regression. Subsequently, the HR was calculated for anchor drug class stratified by each interaction terms (AIDS-defining illness and type of backbone). The filled circles indicate the hazard ratio, while the horizontal lines indicate the 95% CI