Systemic Lupus Erythematosus (SLE) and Rheumatoid Arthritis (RA) have significant disease burden in the USA. Infections have been recognized as a major cause of morbidity and mortality in patients with SLE and RA, not only due to the inflammatory nature of these diseases but due to immunosuppressive treatments. The purpose of this study was to use the National Inpatient Sample (NIS) database to compare the inpatient mortality trends in patients with SLE or RA and selected bacterial infections.
Hospitalizations were identified within the NIS database using ICD 9 codes for SLE and RA and the following infections: septicemia, urologic infection, pneumonia, ventilator associated pneumonia, pulmonary tuberculosis, cellulitis, CNS infections, MRSA, osteomyelitis, sepsis, and bacteremia. Mortality was analyzed in an unadjusted manner with the Rao-Scott Chi-Square test for each group. Crude incidence was calculated based on the total number of hospitalizations. Mortality was analyzed as an age-adjusted annual trend from 2002-2014. SAS v 9.4 and Joinpoint Trend Analysis v 4.5 were used for all analyses; p < 0.05 determined statistical significance.
Approximately 320,022,452 hospitalizations were identified with 1,660,059 selected infections with SLE or RA. SLE showed an age adjusted mortality decline of 5.1% (p < 0.001) annual percent change (APC) from 2002-2014 (56.3 to 30.1 deaths/1000). RA initially showed a decline in mortality from 2002-2004 but had increased mortality from 2004-2014 (2.8% APC, p=0.007). The overall incidence of hospitalizations due to selected infections in those with SLE or RA was estimated to be no more than 5.1/1000 hospitalizations. Septicemia (22.76%) and Ventilator-Associated Pneumonia (17.95%) had the highest in-hospital mortality associated with SLE. Septicemia (26.42%) and pulmonary tuberculosis (22.69%) had the highest in-hospital mortality in those with RA.
SLE shows an overall decline in mortality in those admitted with selected bacterial infections however RA showed an increase in mortality from 2004-2014. It is unclear if this trend may be due to increased use of biologics in RA during this time period. It would be interesting in future studies to analyze the impact of opportunistic infections as it relates to these diseases.
S. Aurit, None
R. Vivekanandan, None