title: Comparative analysis of length of stay, hospitalization costs, opioid use, and discharge status among spine surgery patients with postoperative pain management including intravenous versus oral acetaminophen.
abstract: BACKGROUND
  Recovery from spine surgery is oriented toward restoring functional health outcomes while reducing resource use. Optimal pain management is a key to reaching these objectives. We compared outcomes of spine surgery patients who received standard pain management including intravenous (IV) acetaminophen (APAP) vs. oral APAP.
  
  
  METHODS
  We performed a retrospective analysis of the Premier database (January 2012 to September 2015) comparing spine surgery patients who received pain management with IV APAP to those who received oral APAP, with no exclusions based on additional pain management. We performed multivariable logistic regression for the discharge and all cause 30-day readmission to the same hospital outcomes and instrumental variable regressions using the quarterly rate of IV APAP use for all hospitalizations by hospital as the instrument in two-stage least squares regressions for length of stay (LOS), hospitalization costs, and average daily morphine equivalent dose (MED) outcomes. Models adjusted for age, gender, race, admission type, 3M All Patient Refined Diagnosis Related Group severity of illness and risk of mortality, hospital size, and indicators for whether the hospital was an academic center and whether it was urban or rural.
  
  
  RESULTS
  We identified 112,586 spine surgery patients with 51,835 (46%) having received IV APAP. Subjects averaged 57 and 59 years of age respectively in the IV APAP and oral APAP cohorts and were predominantly non-Hispanic Caucasians and female. In our adjusted models, IV APAP was associated with 0.68 days shorter LOS (95% CI: -0.76 to -0.59, p < .0001), $1175 lower hospitalization costs (95% CI: -$1611 to -$739, p < .0001), 13 mg lower average daily MED (95% CI: -14 mg to -12 mg, p < .0001), 34% lower risk of discharge to a skilled nursing facility (95% CI: 0.63 to 0.69, p < .0001), and 13% less risk of 30-day readmission (95% CI: 0.73 to 1.03).
  
  
  CONCLUSIONS
  Compared to oral APAP, managing post-spine-surgery pain with IV APAP is associated with less resource use, lower costs, lower doses of opioids, and improved discharge status.
authors.affiliation: a University of Washington , School of Pharmacy , Seattle , WA , USA.
authors.forename: Ryan N
authors.initials: RN
authors.lastname: Hansen
authors.affiliation: b Mallinckrodt Pharmaceuticals , Health Economics and Outcomes Research Department , Hampton , NJ , USA.|d School of Pharmacy , University of California San Francisco , San Francisco , CA.
authors.forename: An T
authors.initials: AT
authors.lastname: Pham
authors.affiliation: b Mallinckrodt Pharmaceuticals , Health Economics and Outcomes Research Department , Hampton , NJ , USA.
authors.forename: Elaine A
authors.initials: EA
authors.lastname: Böing
authors.affiliation: b Mallinckrodt Pharmaceuticals , Health Economics and Outcomes Research Department , Hampton , NJ , USA.
authors.forename: Belinda
authors.initials: B
authors.lastname: Lovelace
authors.affiliation: b Mallinckrodt Pharmaceuticals , Health Economics and Outcomes Research Department , Hampton , NJ , USA.
authors.forename: George J
authors.initials: GJ
authors.lastname: Wan
authors.affiliation: c Duke University , School of Medicine , Durham , NC , USA.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Miller
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage* / Q000627:therapeutic use; D061605:Administration, Intravenous; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D005260:Female; D017721:Hospital Costs; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007275:Injections, Intravenous; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D000082:Acetaminophen
keywords: Acetaminophen; comparative effectiveness; pain management; spine surgery