Declining In-Hospital Mortality Gap Between Systemic Lupus Erythematosus (Sle) And Non-Sle Hospitalisations: A National Study

Mortality in systemic lupus erythematosus (SLE) is twofold to threefold higher compared with the general population.1 Overall SLE mortality decreased over time,1 2 but in-hospital mortality has increased.3 We hypothesised an increase in in-hospital mortality rates in SLE and SLE–non-SLE mortality gap over time.\n\nWe included discharges from US National Inpatient Sample (NIS) from 1998 to 2014, the last year of the use of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). The NIS is a 20% stratified sample of hospital discharges. We identified primary SLE hospitalisations based on the presence of an ICD-9-CM code of 710.0x in the primary position; this diagnostic code has a sensitivity of 98% and specificity of 72%.4\n\nWe calculated the unadjusted, age-adjusted and age–sex-adjusted in-hospital mortality rates per 1000 primary SLE hospitalisations versus general non-SLE hospitalisations. We used the Cochran Armitage test to analyse mortality time trends.\n\nThe 241 130 primary SLE hospitalisations in 1998–2014 included predominantly black (34.3%), young (mean age, 36 years) and female (86.9%) patients. Deyo-Charlson Comorbidity Score was ≥2 for 47%; one-third were receiving Medicaid and 1.5% died in-hospital (table 1).\n\nView this table:\n\nTable 1 \nCharacteristics of hospitalisations in people with SLE in the USA from 1998 to 2014*\n\n\n\nUnadjusted mortality in primary SLE hospitalisations wavered over time and decreased significantly from 17.9 per 1000 in 1998 to 9.5 in 2014, versus 28.1 per 1000 to 21.2 in non-SLE (45.2% vs 25.9% reduction; p\u003c0.01 for both; figure 1); SLE hospitalisations occured in much younger people than non-SLE hospitalisations. Age, sex, race/ethnicity did not change over time, …