Introduction: The objective of the present study was to analyze the risk of in-patient mortality, adverse outcome, practice patterns and regional variations in patients who underwent intracranial meningioma surgery in the United States between 2001 and 2010

Methods: We performed a retrospective cohort study using the Nationwide Inpatient Sample database for the years 2001 through 2010. In-patient mortality and adverse outcome at discharge were the outcome predictors. Multivariate analyses were done to analyze the patient, hospital and physician characteristics

Results: The annual case-volume of patients with meningioma increased from 2001 to 2010 by 40%. The in-patient mortality rate remained the same at 1.3% and the rate of adverse discharge disposition remained at 35% between 2001 and 2010 despite minor variations within the decade. Morbidity and mortality were significantly higher in patients with co-morbidities. Caucasian female patients in younger age group with private insurance and treated at a high case volume center had the best outcomes. In elderly patients (= 70 years), the in-patient mortality rate decreased from 4% to 3% whereas the adverse hospital discharge disposition rate increased from 53% to 63%. Patients treated at high case volume centers had lower rates of in-patient mortality (P=0.03) and adverse outcome at discharge (P=0.007). There was a 54% decrease in the number of hospitals performing one surgery/year through the decade. Physicians with high case volumes also had significantly low in-patient mortality and morbidity (P<0.001). A 2% relative decrease in mortality was observed in lowest volume hospitals. Though the highest increase in admission charges through the decade was seen in hospitals located in the north-east (165% relative increase), the highest relative decrease in mortality and morbidity was observed in hospitals located in the mid-west and the south (67.6% and 22% respectively)

Conclusions: The annual case volume increased; the mortality and adverse hospital discharge disposition rates remained the same through the decade. High case volume hospitals and physicians had the least in-patient mortality and adverse hospital discharge disposition rates. Mortality in the elderly age group decreased.

Patient Care: this study helps us to underand the regional and year-wise variations in the treatment of intracranial meningioma. it will help us to plan and organize the establishment of neuro oncology services in the country

Learning Objectives: 1. to understand the trends in intracranial meningioma surgery in the United States 2. to understand the regional differences in treatment of intracranial meningiomas in the United States

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