Gender Disparities in Outcomes of Autoimmune Hemolytic Anemia Admissions: An Analysis of the National Inpatient Sample

Abstract

Introduction Autoimmune hemolytic anemia (AIHA) is a condition characterized by the immune destruction of red blood cells, which can necessitate hospitalization in severe cases. The purpose of this study is to compare outcomes of AIHA hospitalizations between genders. Methods We utilized the International Classification of Diseases (ICD) codes to identify all hospitalizations with the primary diagnosis of AIHA in the National Inpatient Sample (NIS) from 2002 to 2019. We excluded all pediatric (age < 18 years) and elective hospitalizations. We described the baseline characteristics of both groups including demographics and comorbidities. We fitted multivariable logistic regression models to compare outcomes between males and females while adjusting for age, race, and comorbidities. Results A total of 60,529 met the inclusion and exclusion criteria. The majority of these were females (59.1% vs 40.1%, p < 0.001). Males were older (median age 67 vs. 66 years, p < 0.001) and had more white race (73.4% vs. 67.9%, p < 0.001). The distribution of associated comorbidities also differed different between both groups ( (Table 1). On adjusted analysis, males had higher in-hospital mortality rates. They also had higher rates of most secondary outcomes; including rates of circulatory shock, need for mechanical ventilation, bacterial pneumonia, acute myocardial infarction, deep vein thrombosis, hemorrhagic stroke, acute kidney injury, and requiring new hemodialysis. Females had higher rates of urinary tract infections. No significant differences were found in the rates of requiring blood transfusions, sepsis, acute heart failure, pulmonary embolism, ischemic stroke, encephalopathy, and gastrointestinal bleeding (Figure 1). Furthermore, male hospitalizations were associated with higher costs (median [IQR] of $11,400 [6,700-20,500] vs. $10,000 [6,000- 17,200]) despite similar length of stay (median [IQR] of 4 days [3-7] vs. 4 days [3-7]). Conclusion Male patients hospitalized with AIHA experience poorer in-hospital compared to females. More research is essential to understand the underlying causes for these disparities and to tailor management to improve outcomes for both male and female AIHA patients.