Introduction: A previous study of the Medicare database has shown that Normal Pressure Hydrocephalus (NPH) is an underdiagnosed condition affecting the elderly population and that the costs associated with its surgical management are less than those associated with conservative management. Our aim is to determine if the rate of diagnosis of NPH has improved over the last decade and if surgical treatment costs have remained lower than those associated with conservative therapy.

Methods: Retrospective study based on data from a nationally representative random sample of 2,378,637 Medicare beneficiaries (2006-2010). Cohort population was defined as patients with NPH (ICD-9-CM 331.3, 331.4, and 331.5). Two measures of shunt surgery (presence of shunting procedure and number of days after the first shunt procedure was performed) were used and shunt revision, replacement, and removal were analyzed as independent variables. Five primary-outcome measures for NPH healthcare expenditures were assessed by using linear and logistic models.

Results: 2,321 patients with NPH (0.2% prevalence) were included, with 580 (24.99%) receiving a first shunt procedure. The adjusted effect of the procedure is that total 5-year expenditures are $11,676 more per patient (p<0.001) than expenditures associated with non-surgical management. Shunt revision ($22,715, p<0.01) and/or replacement ($46,607, p<0.001), add significantly to 5-year expenditures.

Conclusions: There was a 1.66-fold increase in the rate of diagnosis of NPH, from 0.12% in 1999 to 0.2% in 2008. The total costs per surgical patient rose by approximately 145-160% comparing 2001 and 2010. This increase was mainly due to hospital (by 167-168%) and home health costs (by 118-148%).

Patient Care: By understanding our care advancements over time to establish short and long terms strategies to better diagnose, treat and follow the patients with NPH, but also generating new budgets for their care.

Learning Objectives: To determine if the rate of diagnosis of NPH has improved over the last decade and if surgical treatment costs have remained lower than those associated with conservative therapy.

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