Comparison of the long-term efficacy between tenofovir and entecavir in chronic hepatitis B patients

Correspondence to Professor Jiean Huang, Department of Gastroenterology, Guangxi Medical University, Nanning 530000, China; hjaxiaohua@126.com We read with interest the work by Su et al concerning whether entecavir and tenofovir are equally effective for chronic hepatitis B patients.1 They concluded that there was no significant difference between tenofovir and entecavir in reducing the risk of death/liver transplant or hepatocellular carcinoma (HCC). [...]when describing the cumulative incidence of death/liver transplant, the Kaplan-Meier curve for tenofovir is nearly identical to that for entecavir to the fourth year but superior to entecavir after that (figure 1D in Su et al). When the antiviral regimen was treated as time-varying exposure, the time-varying HRs from the time-dependent Cox regression could exhibit the dynamic risks of event based on treatment duration intuitively.9 10 In this study, Su et al have addressed this issue of antiviral adherence by modelling antiviral regimen as a time-varying covariate, but did not intend to overcome this reported limitation with reporting time-varying effects of the antiviral therapy.