title: Predictors of unfavorable outcomes following deep brain stimulation for movement disorders and the effect of hospital case volume on outcomes: an analysis of 33, 642 patients across 234 US hospitals using the National (Nationwide) Inpatient Sample from 2002 to 2011.
abstract: OBJECTIVE
  With limited data available on association of risk factors and effect of hospital case volume on outcomes following deep brain stimulation (DBS), the authors attempted to identify these associations using a large population-based database.
  
  
  METHODS
  The authors performed a retrospective cohort study involving patients who underwent DBS for 3 primary movement disorders: Parkinson's disease, essential tremor, and dystonia from 2002 to 2011 using the National (Nationwide) Inpatient Sample (NIS) database. Using national estimates, the authors identified associations of patient demographics, clinical characteristics, and hospital characteristics on short-term postoperative outcomes following DBS. Additionally, effect of hospital volume on unfavorable outcomes was investigated.
  
  
  RESULTS
  Overall, 33, 642 patients underwent DBS for 3 primary movement disorders across 234 hospitals in the US. The mean age of the cohort was 63.42 ± 11.31 years and 36% of patients were female. The inpatients' postoperative risks were 5.9% for unfavorable discharge, 10.2% for prolonged length of stay, 14.6% for high-end hospital charges, 0.5% for wound complications, 0.4% for cardiac complications, 1.8% for venous thromboembolism, and 5.5% for neurological complications, including those arising from an implanted nervous system device. Compared with low-volume centers, odds of having an unfavorable discharge, prolonged LOS, high-end hospital charges, wound, and cardiac complications were significantly lower in the high-volume and medium-volume centers.
  
  
  CONCLUSIONS
  The authors' study provides individualized estimates of the risks of postoperative complications based on patient demographics and comorbidities and hospital characteristics, which could potentially be used as an adjunct for risk stratification for patients undergoing DBS.
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.
authors.forename: Piyush
authors.initials: P
authors.lastname: Kalakoti
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.
authors.forename: Osama
authors.initials: O
authors.lastname: Ahmed
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.
authors.forename: Papireddy
authors.initials: P
authors.lastname: Bollam
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.
authors.forename: Symeon
authors.initials: S
authors.lastname: Missios
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.
authors.forename: Jessica
authors.initials: J
authors.lastname: Wilden
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, Louisiana.
authors.forename: Anil
authors.initials: A
authors.lastname: Nanda
mesh_terms: D000368:Aged; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007297:Inpatients; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000628:therapy*; D010351:Patient Discharge / Q000706:statistics & numerical data*; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D014481:United States
keywords: AUC = area under the curve; CCI = Charlson Comorbidity Index; CRF = chronic renal failure; DBS = deep brain stimulation; DM = diabetes mellitus; HCUP = Healthcare Cost and Utilization Project; HVC = high-volume center; LOS = length of stay; LVC = low-volume center; MVC = medium-volume center; NIS = National (Nationwide) Inpatient Sample; National (Nationwide) Inpatient Sample; PD = Parkinson’s disease; ROC = receiver operating characteristic; deep brain stimulation; movement disorders; unfavorable outcomes