Background/Purpose:

Patients with systemic sclerosis (SSc) experience high
rates of morbidity and mortality, but few studies have evaluated health care
utilization such as hospitalization rates and in-hospital mortality associated
with SSc. Moreover, it is unclear if and how these domains have changed over
time and how they compare to other systemic rheumatic conditions. To address
this knowledge gap, we evaluated in-hospital mortality and overall
hospitalization trends in patients with SSc between 1999 and 2011 using a US
nationwide inpatient database.

Methods:

The US National Inpatient Sample (NIS) contains all
discharge data from a sample of hospitals from 44 states, making it the largest
publicly available all-payer inpatient health care database in the US. We
studied all hospitalizations between 1999 and 2011 of adults (≥18
years) with a primary discharge diagnosis of SSc, identified by ICD-9 CM code
710.1. We evaluated in-hospital
mortality and hospitalization rates over time and compared these rates to those
of the overall hospitalized population and other systemic rheumatic conditions.
All analyses were performed using hospital-level sampling weights provided by
the NIS to obtain US national estimates.

Results:

Between 1999 and 2011, the rate of in-hospital
mortality for patients admitted with SSc decreased from 9.6% to 5.8% (p for
trend, <0.001), representing a yearly relative decrease of 4.0% (95% CI
-7.2% to -0.8%) (Figure 1). Despite
this decline, the in-hospital mortality rate in 2011 for patients with SSc
(5.8%) remained substantially higher than for other systemic rheumatic conditions,
including systemic lupus erythematosus (SLE) (0.93%) and granulomatosis with
polyangiitis (2.6%), as well as than for the overall hospitalized population
(2.1%). Among patients with a
primary diagnosis of SSc who died during their hospitalization, the five most
common secondary diagnoses were lower respiratory disease, fluid and electrolyte
disorders, respiratory failure, pulmonary vascular disease and renal failure.
These diagnoses did not change substantially during the study period, with the
exception of congestive heart failure, which was replaced by renal failure.
From 1999 to 2011, the rate of overall hospitalizations for SSc decreased
slightly from 1.06 to 0.81 per 100,000 persons.

Conclusion:

Based on nationally representative inpatient data, our
findings indicate a decrease in SSc in-hospital mortality between 1999 and
2011, suggesting that clinical care of SSc patients may be improving. Despite
this encouraging trend, the in-hospital mortality rate remains approximately
6%, which is considerably higher than that of both the overall hospitalized
population and any other systemic rheumatic condition. This highlights the need
for continued improvement in the care of patients with SSc, including the development
and implementation of effective therapeutic modalities.