title: Evaluation of incremental healthcare resource burden and readmission rates associated with hospitalized hyponatremic patients in the US.
abstract: BACKGROUND
  Hyponatremia is a prevalent electrolyte disorder in hospitalized patients indicative of greater morbidity and mortality. A large-scale retrospective analysis was conducted to evaluate the incremental burden of hospitalized hyponatremic (HN) versus non-HN patients in terms of hospital resource utilization, costs, and hospital readmissions in the real-world setting.
  
  
  METHODS
  HN patients (≥18 years) were selected from the Premier Hospital Database between January 1, 2007 and March 31, 2010 and matched to a non-HN control cohort using propensity score matching. Bivariate and multivariate statistics were employed to evaluate the differences in healthcare resource utilization, costs, and hospital readmissions between patient cohorts.
  
  
  RESULTS
  Among the matched patient cohorts, length of stay (LOS) (8.8 ± 10.3 vs 7.7 ± 8.5 days, P < 0.001), hospital admission costs ($15,281 ± $24,054 vs $13,439 ± $22,198, P < 0.001), intensive care unit (ICU) LOS (5.5 ± 7.9 vs 4.9 ± 7.1 days, P < 0.001), and ICU costs ($8525 ± $13,342 vs $7597 ± $12,695, P < 0.001) were greater for the HN versus non-HN cohort, as were hospital readmission rates 30 days postdischarge. Multivariate regressions further demonstrated that hyponatremia was associated with an increase of 10.9% for LOS, 8.2% for total hospitalization costs, 10.2% for ICU LOS, and 8.9% for ICU costs. Additionally, after multivariate adjustment, hyponatremia was associated with a 15.0% increased chance for hospital readmission 30 days postdischarge (P < 0.0001).
  
  
  CONCLUSIONS
  Hyponatremia is an independent predictor of increased hospitalization LOS and cost, ICU admission and cost, and 30-day hospital readmission, and therefore represents a potential target for intervention to reduce healthcare expenditures for a large population of hospitalized hyponatremic patients.
authors.affiliation: Department of Medicine, University of California, Irvine, Irvine, California, USA. anamin@hs.uci.edu
authors.forename: Alpesh
authors.initials: A
authors.lastname: Amin
authors.forename: Steven
authors.initials: S
authors.lastname: Deitelzweig
authors.forename: Rudell
authors.initials: R
authors.lastname: Christian
authors.forename: Keith
authors.initials: K
authors.lastname: Friend
authors.forename: Jay
authors.initials: J
authors.lastname: Lin
authors.forename: Kathy
authors.initials: K
authors.lastname: Belk
authors.forename: Dorothy
authors.initials: D
authors.lastname: Baumer
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Lowe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D017048:Health Care Costs; D006295:Health Resources / Q000706:statistics & numerical data*; D006801:Humans; D007010:Hyponatremia / Q000191:economics*; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010359:Patient Readmission / Q000706:statistics & numerical data*; D057216:Propensity Score; D012189:Retrospective Studies; D014481:United States