Adherence to hydroxychloroquine improves long-term survival of patients with systemic lupus erythematosus.

Objectives: HCQ, which is known to decrease SLE activity, may have a protective effect on survival, but this has not been proven in Asia. This study aimed to determine whether HCQ treatment is associated with increased survival in patients with SLE.

Methods: We designed this prospective SLE cohort study using data from the Taiwan National Health Insurance Research Database. The participants were divided into HCQ and control groups according to whether HCQ was prescribed during the first year after an SLE diagnosis. The primary outcome was mortality 1 year after inclusion. In the subgroup analysis, these participants were divided based on medication possession ratio (MPR) in the first year into non-users, MPR <40%, 40% ⩽ MPR < 80% and MPR ⩾80% subgroups to explore the relationship between survival and HCQ adherence.

Results: A total of 12 443 patients were eligible for the analysis. After propensity score matching, we included 2287 patients in each group. During a mean follow-up of 7.6 years, there were 169 events in the HCQ group (7.4%) and 248 events in the control group (10.8%). The risk of mortality in the HCQ group was lower than that in the control group (hazard ratio = 0.68; 95% CI: 0.56, 0.82). The subgroup analysis revealed that the survival protective effect was associated with HCQ adherence.

Conclusion: Patients with SLE who received HCQ had lower mortality rates due to any cause than those who did not. The survival benefit could be augmented by HCQ adherence.