title: Impact of Inpatient Venous Thromboembolism Continues After Discharge: Retrospective Propensity Scored Analysis in a Longitudinal Database.
abstract: METHODS
  Propensity score matched retrospective study using a nationwide longitudinal database.
  
  
  OBJECTIVE
  To quantify the longitudinal economic impact of venous thromboembolism (VTE) complications in spinal fusion patients.
  
  
  BACKGROUND
  VTE is a rare and serious complication that may occur after spine surgery. The long-term socioeconomic impact understanding of these events has been limited by small sample sizes and a lack of longitudinal follow-up. We provide a comparative economic outcomes analysis of these complications.
  
  
  METHODS
  We identified 204,308 patients undergoing spinal fusion procedures in a national billing claims database (MarketScan) between 2006 and 2010. Cohorts were balanced using 50:1 propensity score matching and outcome measures compared at 6, 12, and 18 months postoperation.
  
  
  RESULTS
  A total of 1196 (0.6%) patients developed postoperative VTE, predominantly occurring following lumbar fusion (69.7%). Postoperative VTE patients demonstrated an increase in hospital length of stay (7.8 vs. 3.3 d, P<0.001) and a decreased likelihood of being discharged home (71% vs. 85%, P<0.001). A $26,306 increase in total hospital payments (P<0.001) was observed, with a disproportionate increase seen in hospital payments ($22,103, P<0.001), relative to physician payments ($1766, P=0.001).At 6, 12, and 18 months postfusion, increased rates of readmission and follow-up clinic visits were observed. Delayed readmissions were associated with decreased length of stay (3.6 vs. 4.6 d, P<0.001), but increased total payments, averaging at $21,270 per readmission. VTE patients generated greater cumulative outpatient service payments, costing $8075, $11,134, and $13,202 more at 6, 12, and 18 months (P<0.001).
  
  
  CONCLUSIONS
  VTEs are associated with longer hospitalizations, a decreased likelihood of being discharged home, and overall increases of hospital resource utilization and cost in inpatient and outpatient settings. VTE patients generate greater charges in the outpatient setting and are more likely to become readmitted at 6, 12, and 18 months after surgery, demonstrating a significant socioeconomic impact long after occurrence.
  
  
  METHODS
  Level III-therapeutic.
authors.affiliation: Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Alexander Y
authors.initials: AY
authors.lastname: Li
authors.forename: Tej D
authors.initials: TD
authors.lastname: Azad
authors.forename: Anand
authors.initials: A
authors.lastname: Veeravagu
authors.forename: Inderpreet
authors.initials: I
authors.lastname: Bhatti
authors.forename: Amy
authors.initials: A
authors.lastname: Li
authors.forename: Tyler
authors.initials: T
authors.lastname: Cole
authors.forename: Atman
authors.initials: A
authors.lastname: Desai
authors.forename: John K
authors.initials: JK
authors.lastname: Ratliff
mesh_terms: D016208:Databases, Factual; D005260:Female; D006295:Health Resources / Q000706:statistics & numerical data; D006801:Humans; D007297:Inpatients; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000401:mortality; D057216:Propensity Score; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects*; D054556:Venous Thromboembolism / Q000503:physiopathology / Q000601:surgery*