Mortality risk in splenectomised patients: A Danish population-based cohort study

Abstract Background The extent and magnitude of mortality risk among patients splenectomised for a variety of indications is not well-described in the literature. We assessed mortality risk among splenectomised patients compared to the general population and to un-splenectomised patients with similar underlying medical conditions. Methods We conducted a historical population-based cohort study in Denmark between January 1, 1996 and December 31, 2005. Mortality risk was evaluated within 90 days, 91–365 days, and > 365 days post- splenectomy, controlling for age, sex, and comorbid conditions using Cox proportional hazards models for a splenectomised cohort compared to the general Danish population and a matched indication cohort. Results We identified a total of 3812 splenectomised patients, 38,120 population comparisons, and 8310 matched indication comparisons. Within 90 days post- splenectomy, the adjusted relative risk (RR) for death, regardless of indication, was highly elevated compared to the general population: RR 33.6 [95% confidence interval (CI): 6.9, 35.0]. This risk declined substantially after 90 days post- splenectomybut remained higher 365 days post- splenectomyfor all indications compared to the general population. When compared to the matched indication cohort, short- and long-term mortality risk with splenectomywas not increased. Conclusion Regardless of indication, the adjusted short- and long-term risk of death for splenectomised patients was higher than the general population. Most of this risk seems to be due to the underlying splenectomyindication and not to splenectomyalone.