In-hospital mortality and associated factors in patients with systemic lupus erythematosus: analysis over more than 11 years in a reference hospital center.

Systemic lupus erythematosus (SLE) is a disease that affects the immune system, and it can lead to increased morbidity and mortality. The primary causes of mortality for individuals with SLE are disease activity, infections, drug toxicity, and other health conditions. The aim of this study is to estimate the mortality rate of patients with SLE who are hospitalized, describe the causes of death, and identify factors associated with mortality. The study was conducted at a referral hospital from 2009 to 2021, utilizing a nested case-control design. The records of patients with SLE who were hospitalized in the Department of Rheumatology were reviewed. Cases were identified as individuals who died during their hospitalization, while controls were those who were discharged alive during the same period. Elective hospitalizations were not included in the study. The primary causes of death were recorded, and demographic, clinical, laboratory, and immunological variables were analyzed as potential risk factors associated with in-hospital mortality. The study included 105 patients who died while hospitalized and 336 who were discharged alive. The estimated mortality rate was 10.93 deaths per 1000 hospital admissions per year. The leading causes of death were SLE activity (20%), infections (34.2%), or a combination of both (24.8%). Risk factors associated with in-hospital mortality were any infection (OR 2.5, CI 95% 1.2-5.2), nosocomial infections (OR 5.0, CI 95% 1.8-13.7), SLEDAI-2K > 2 (OR 2.0, CI 95% 1.02-3.8), lymphopenia (OR 2.1, CI 95% 1.01-4.6), anemia (OR 2.9, CI 95% 1.4-5.7), and thrombocytopenia (OR 3.3, CI 95% 1.7-6.4). Disease activity and infections, particularly nosocomial infections, are significant causes of mortality in hospitalized patients with SLE. Furthermore, hematological manifestations play a significant role in in-hospital mortality for these patients.