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.