Time-Dependent Mortality Predictors in Primary Sjögren's Syndrome: C-Reactive Protein for Early Risk and Age for Late Outcomes.

Purpose: To identify risk factors for near-term and long-term death in patients with primary Sjogren's syndrome (pSS). Patients and Methods: This ambispective cohort study included all patients with pSS treated at China-Japan Friendship Hospital between 2013 and 2023. The time-dependent Cox regression analysis was used for statistical analysis of risk factors, with 3 months and 60 months as the cut-off time points and all-cause death as the primary endpoint. Results: Among the 1252 included patients, 138 patients had died by the end of follow-up (11.0%). Age at diagnosis, C-reactive protein (CRP) levels and total bilirubin (TBIL) were time-dependent risk factors for mortality. Within 3 months of follow-up, age > 65 years had no effect on mortality, but after 3 months of follow-up, the mortality risk in patients aged > 65 years increased over time (HR 3.97, 95% CI 2.57-6.13; HR 16.63, 95% CI 5.53-50.03). CRP >6.5 mg/L increased the risk of mortality within 3 months (HR=11.45, 95% CI 2.52-51.95), followed by 3-60 months (HR=2.94, 95% CI 1.94-4.45), but did not affect survival after 60 months of follow-up. TBIL >18.01 µmol/L increased the risk of mortality in pSS patients within 3-6 months (HR=2.30, 95% CI 1.42-3.79) but did not increase the risk of mortality in patients with pSS within 3 months of follow-up or after 60 months. Conclusion: pSS patients with a CRP level >6.5 mg/L have an 11-fold increased risk of near-term death, whereas pSS patients older than 65 years of age at diagnosis have a 16-fold increased risk of long-term death.