Mortality, length of stay and cost of hospitalization among patients with systemic sclerosis: results from the National Inpatient Sample

Objectives. To evaluate the hospitalizations and define the factors associated with in-hospital mortality, longer length of stay (LOS) and higher hospital costs among SSc hospitalizations. Methods. We used the National Inpatient Sample (2012-13) to identify adult hospitalizations with SSc, excluding patients with concomitant diagnosis of RA and systemic lupus. We calculated rates of hospitalization, in-hospital mortality, LOS and hospital costs. Factors associated with these outcomes were evaluated by univariate and backward stepwise multivariate logistic regression. Results. There were 9731 hospitalizations in the sample representing an estimated 48 655 hospitalizations nationwide with SSc (0.09%), and the inpatient mortality rate was 5%. Patients were predominantly older (mean age 63.2 years), female (82.2%) and Caucasian (71.5%). Infections were the most common primary diagnoses among SSc hospitalizations (17.4%) and among those who died (32.7%). Acute renal failure [adjusted odds ratio (aOR) = 4.3, 95% CI: 3.3, 5.6] and aspiration (aOR= 3.5, 95% CI: 2.5, 4.9) were strongly associated with in-hospital mortality. The median (interquartile range) LOS was 4 days (-2, 7), and the median (interquartile range) cost was $ 8885 (-5169, 15921). While hospital from the West region, acute renal failure, acute bowel obstruction and aspiration (aOR> 2.0 with P< 0.0001 for all) seem to predict higher cost of hospitalization, pulmonary fibrosis, myositis and any type of infection in addition to the same factors, except the West region (aOR> 2.0 with P< 0.0001 for all), were associated with longer LOS. Conclusion. Infections are currently the most common diagnoses among SSc hospitalizations and in-hospital deaths. This emphasizes the importance of being vigilant in prevention and early treatment of infections in SSc patients.