title: Cumulative illness severity and progression from moderate to severe retinopathy of prematurity.
abstract: OBJECTIVE
  To test cumulative neonatal illness severity (IS) and IS fluctuation as predictors of progression from moderate to severe retinopathy of prematurity (ROP).
  
  
  METHODS
  Data from research databases and medical record review were collected for infants from four neonatal intensive care unit (NICUs) admitted between 1995 and 2001 and diagnosed with prethreshold ROP. Cumulative neonatal IS measured using daily Scores for Neonatal Acute Physiology (SNAP) for the first 28 days of life, and IS fluctuation as assessed by summing changes between daily SNAP scores, were tested as predictors of progression to threshold ROP using logistic regression.
  
  
  RESULTS
  Infants progressing to threshold (n=79), compared to those not progressing to threshold (n=130), had significantly (P<0.05) lower gestational ages (25.2+/-1.1 versus 25.8+/-1.4 weeks), higher cumulative neonatal SNAP (255+/-77 versus 224+/-63 weeks) and had more severe hospitalizations as indicated by diagnoses and medical management. In regression analysis, gestational age, chronological age and presence of plus disease at first diagnosis of prethreshold were associated with development of threshold. After adjusting for these factors, cumulative neonatal SNAP was significantly associated with progression to threshold. However, addition of cumulative SNAP to the model only increased receiver-operating characteristic curve area from 0.77 to 0.78 (NS). Other factors, including SNAP fluctuation, were not associated with progression to threshold after adjustment using this model.
  
  
  CONCLUSIONS
  Cumulative neonatal IS, as measured by cumulative SNAP, is an independent risk factor for progression from moderate to severe ROP. However, cumulative IS does not enhance assessment of risk for ROP progression after adjusting for simpler clinical factors.
authors.affiliation: Division of Neonatology, Department of Pediatrics, Connecticut Children's Medical Center, University of Connecticut School of Medicine, Hartford, CT 06106, USA. jhagadorn@ccmckids.org
authors.forename: J I
authors.initials: JI
authors.lastname: Hagadorn
authors.forename: D K
authors.initials: DK
authors.lastname: Richardson
authors.forename: C H
authors.initials: CH
authors.lastname: Schmid
authors.forename: C H
authors.initials: CH
authors.lastname: Cole
mesh_terms: D000367:Age Factors; D015897:Comorbidity; D018450:Disease Progression; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D012178:Retinopathy of Prematurity / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index