Health Care Expenditures of Medicare Beneficiaries with Normal Pressure Hydrocephalus

Normal pressure hydrocephalus (NPH) is an underdiagnosed and undertreated condition affecting the elderly population and with costs associated with its surgical management reported to be less than those associated with conservative management.

To determine if the rate of diagnosis of NPH has improved over the last decade, the rate of treatment has increased, and if surgical treatment costs and socioeconomic factors related to receipt of treatment have changed over time compared with conservative therapy.

A retrospective study based on data from a nationally representative random sample of 2,378,637 Medicare beneficiaries (2006-2010) was performed. Shunt surgery, shunt revision, replacement, and removal were analyzed as independent variables.

A total of 2321 patients with NPH 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 nonsurgical management. Shunt revision ($22,715, P < 0.01) and/or replacement ($46,607, P < 0.001) add significantly to 5-year expenditures. Socioeconomic factors including African American race (P = 0.006); age 75-79 years (P = 0.024), 80-84 years (P < 0.001), and ≥85 years (P < 0.001); and Medicaid (P < 0.001) have significant negative associations with shunt surgery.

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% to 160% comparing 2001 and 2010. This increase was mainly due to hospital (by 167% to 168%) and home health costs (by 118% to 148%). Providing appropriate care across the socioeconomic spectrum warrants further study and requires identifying the factors that limit access to care.