Systemic lupus international collaborating clinics frailty index predicts mortality in systemic lupus erythematosus patients: data from the Almenara Lupus Cohort

Abstract

Objective Frailty has been shown to predict damage accrual in patients with systemic lupus erythematosus (SLE), including those from Latin America. However, the impact of frailty on mortality has been scarcely evaluated, particularly in Latin American populations. The aim of this study was to evaluate frailty as a predictor of mortality in Latin American SLE patients.

Methods Patients from a single-centre 2012–2025 prevalent cohort were studied. Mortality was defined as the vital status according to the Peruvian Department of Health. Frailty was ascertained using the Systemic Lupus International Collaborating Clinics Frailty Index (SLICC-FI) as a continuous variable. Univariable and multivariable Cox regression models were done to estimate its impact on mortality. Multivariable models were adjusted for possible confounders. Sensitivity analyses were performed including data up to March 2020 to avoid the potential influence of the COVID-19 pandemic. Additionally, a Kaplan-Meier curve was calculated by frail status (frail, SLICC-FI >0.21; non-frail, SLICC-FI ≤0.21).

Results Four hundred and ninety-five patients were included, 456 (92.1%) were women and 96 (19.4%) were frail. Their mean (SD) age at diagnosis was 35.0 (14.0) years, their mean disease duration at baseline was 6.7 (6.1) years and their mean follow-up time was 8.5 (4.2) years. Fifty-six (11.3%) patients died during the follow-up. The SLICC-FI predicted mortality even after adjusting for possible confounders (hazard ratio (HR)=1.54 (CI 95% 1.11 to 2.14), p=0.010). This prediction capability remained on the sensitivity analyses (HR 1.85; (95% CI 1.30 to 2.61), p<0.001).

Conclusion Frailty, as ascertained with the SLICC-FI, was a predictor of mortality in a Latin American cohort of SLE patients. Frailty could be considered in the monitoring of SLE patients; possible interventions to modify it should be developed.