title: Incremental Hospital Costs Associated With Comorbidities of Prematurity.
abstract: OBJECTIVE
  Preterm birth (PTB), defined as birth at a gestational age (GA) of less than 37 weeks, is associated with increased hospital costs. Lower GA at birth is negatively correlated with the presence of neonatal comorbidities, further increasing costs. This study evaluated incremental costs associated with comorbidities of PTB following spontaneous labor at 24-36 weeks.
  
  
  METHODS
  Birth records from January 2001 to December 2010 at the Medical University of South Carolina were screened to identify infants born at GA 23-37 weeks after uncomplicated singleton pregnancies and surviving to discharge.
  
  
  METHODS
  Comorbidities of interest and incremental costs were analyzed with a partial least squares (PLS) regression model adjusted for comorbidities and GA. Incremental comorbidity-associated costs, as well as total costs, were estimated for infants of GA 24-36 weeks.
  
  
  RESULTS
  A total of 4,292 delivery visit records were analyzed. Use of the PLS regression model eliminated issues of multicollinearity and allowed derivation of stable cost estimates. Incremental costs of comorbidities at a mean GA of 34 weeks ranged from $4,529 to $23,121, and exceeded $9,000 in 6 cases. Incremental costs rangedfrom a high of $41,161 for a GA 24-week infant with a comorbidity of retinopathy of prematurity requiring surgery (ROP4) to $3,683 for a GA 36-week infant with a comorbidity of convulsions. Incremental comorbidity costs are additive, so the costs for infants with multiple comorbidities could easily exceed the high of $41,161 seen with ROP4.
  
  
  CONCLUSIONS
  The PLS regression model allowed derivation of stable cost estimates from multivariate and highly collinear data and can be used in future cost analyses. Using this data set, predicted costs of all comorbidities, as well as total costs, negatively correlated with GA at birth.
authors.forename: Libby
authors.initials: L
authors.lastname: Black
authors.forename: Thomas
authors.initials: T
authors.lastname: Hulsey
authors.forename: Kwan
authors.initials: K
authors.lastname: Lee
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Parks
authors.forename: Myla D
authors.initials: MD
authors.lastname: Ebeling
mesh_terms: D015897:Comorbidity; D005260:Female; D017721:Hospital Costs; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D017283:Neonatal Nursing / Q000191:economics*; D047928:Premature Birth / Q000191:economics* / Q000451:nursing; D012042:Registries; D012189:Retrospective Studies; D013022:South Carolina