Patient Risk Factors Associated with 30- and 90- Day Readmission after Ventriculoperitoneal Shunt Placement for Idiopathic Normal Pressure Hydrocephalus in Elderly Patients: A Nationwide Readmission Study.

ABSTRACT Objective For idiopathic normal pressure hydrocephalus (iNPH), risk stratifying patients and identifying those who are likely to fare well after ventriculoperitoneal shunt (VP) surgery may help improve quality of care and reduce unplanned readmissions. The aim of this study was to investigate the drivers of 30- and 90-day readmissions following VP shunt surgery for iNPH in elderly patients. Methods The Nationwide Readmission Database years 2013 – 2015 was queried. Elderly patients (≥ 65 years old) undergoing VP shunt surgery were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Unique patient linkage numbers were used to follow patients and identify 30- and 31 to 90-day readmission rates. Patients were grouped by no readmission (Non-R), readmission within 30 days (30-R), and readmission within 31 to 90 days (90-R). Results We identified 7,199 elderly patients undergoing VP shunt surgery for iNPH. 1,413 (19.6%) patients were readmitted (30-R: n = 812 [11.3%] vs. 90-R: n = 601 [8.3%] vs. Non-R: n = 5,786). The most prevalent 30- and 90-day complications seen among the readmitted cohort were mechanical complication of nervous system device implant (30-R: 16.1%, 90-R: 12.4%), extracranial postoperative infection (30-R: 10.4%, 90-R: 7.0%), and subdural hemorrhage (30-R: 6.0%, 90-R: 16.4%). On multivariate regression analysis, age, diabetes, and renal failure were independently associated with 30-day readmission; female sex and 26-50th household income percentile were independently associated with reduced likelihood of 90-day readmission. Having any complication during the index admission independently associated with both 30- and 90-day readmission. Conclusions In this study, we identify the most common drivers for readmission for elderly patients with iNPH undergoing VP shunt surgery.