"Outcomes of Hospitalized Patients with Immune Thrombocytopenia and Splenectomy in 2017: A Nationwide Cross-Sectional Analysis"

Background: Immune Thrombocytopenic Purpura (ITP) is an autoimmune disorder characterized by premature platelet destruction. Often considered treatable, patients with ITP can relapse even with initial steroid treatment. Splenectomy is currently regarded as the standard second-line therapy for steroid-refractory ITP. However, the outcomes of patients who have undergone splenectomy for ITP have not been well-assessed. Studies investigating the prevalence and in-hospital mortality of these patients have been limited to case reports and case series. By conducting a retrospective analysis of nationwide data, we sought to elucidate the outcomes of hospitalized patients with ITP who have undergone splenectomy.

Methods: Data from the National Inpatient Sample was extracted to identify and characterize outcomes in hospitalized patients with ITP who underwent splenectomy in the year 2017. The National Inpatient Sample is a database maintained by the Agency for Healthcare Quality and Research. The International Classification of Diseases, 9th Edition, Clinical Modification codes were used to identify patients with ITP. Patient demographics of age, gender and race and hospital characteristics of disposition, size, location, region and teaching status were collected. Patient medical expenses and insurances were also obtained. Common associated medical complications and comorbidities such as morbid obesity, chronic kidney disease, pulmonary and autoimmune diseases were studied in ITP patients who died with and without splenectomy. Chi square test was used to determine odds ratios and multiple logistic regression was used to determine independent predictors of mortality.

Results: 11,106 patients with ITP were hospitalized in the year 2017. Of these, a total of 218 patients underwent splenectomy. Four patients (1.8%) who underwent splenectomy died. Assessing the general population with ITP, females were affected more than males (58.8% females vs. 41.2% males), but males were more likely to suffer mortality (p=0.0000). Females underwent more splenectomy procedures compared to their male counterparts (129 vs. 85). Large-sized hospitals and teaching hospitals were noted to have the majority of procedures. A majority of patients with splenectomy and ITP were covered by Medicare. Both patients who did or did not undergo splenectomy tended to remain in the hospital for about 2-5 days. Patients with ITP tended to undergo the procedure during an elective admission compared to a non-elective admission despite there being a greater number of non-elective admissions (150 vs. 68, 1,829 vs. 9,257). Assessing cost, patients undergoing splenectomy tended to be in the higher expense group >$25,000.

Conclusion: This is the first nationwide study to document the outcomes of splenectomy in hospitalized patients with ITP. This investigation demonstrates that the mortality of patients who undergo splenectomy for ITP is noninferior to the general population with ITP. Regardless of comorbidities, patients did favorably well with splenectomy and tended to have similar hospital stays to patients who did not undergo procedures. Thus, they do not have worse outcomes. Notably, patients admitted non-electively were less likely to undergo the procedure, likely given the increased complications of their hospital course. Further research is needed to better characterize both the short and long-term outcomes in this patient population.