Introduction: Prior studies of outcomes from surgery for iNPH may not be generalizable, since most are from high volume centers. The objective of this study was to perform a nationwide analysis of the patient selection and outcomes associated with surgery for iNPH.
Methods: The Nationwide Inpatient Sample (NIS) was analyzed from 2003-2009 for patients greater than 50 years old with ICD-9 code 331.3 (and 331.5 for 2008 and 2009) and ICD9-CM codes 02.3 and 02.43. Patients with ICD-9 codes for potential causes of secondary hydrocephalus or NPH, e.g., subarachnoid hemorrhage, were excluded. Two-tailed Chi square with Yates correction was used.
Results: 8340 patients were identified in the sample, corresponding to between 4374 and 6755 cases per year in the US. There was no increase in surgery frequency after guideline publication in September 2005. Blacks were underrepresented (5% vs. 9.9% of the US population >50 years old, p<0.001). Cases per surgeon ranged between 1 and 22 per year with a mean of 2. Median length of stay was 3 days. Complications were coded in 12.5% of patients, including UTI (7.4%), pneumonia (3.5%), prolonged ventilation (2.9%), sepsis (1.4%), feeding tube placement (1.4%) , DVT (0.7%), pulmonary embolus (0.2%) and death (1.0%). Median hospital charges were $28,000. Extrapolated annual inpatient charges for surgeries for iNPH for the US ranged between $153 million in 2004 and $317 million in 2009. Discharge was to home in 61%, with 13% having home health care, and to rehab or a nursing facility in 37%.
Conclusions: While NIS data do not illuminate long-term outcomes, they can be used to estimate perioperative complications, discharge status and inpatient costs. In addition, they suggest that the guidelines for surgery for iNPH did not lead to increased utilization and there may be racial disparities in the treatment of iNPH.
Patient Care: Increase awareness of high rates of complications associated with surgery for NPH amongst clinicians and patients. Reduce racial disparities.
Learning Objectives: By the conclusion of the session, participants should be able to 1)Describe the short-term complications of surgery for iNPH 2)Understand the power and limitations of the Nationwide Inpatient Sample