title: Treatment for retinopathy of prematurity in Denmark in a ten-year period (1996 2005): is the incidence increasing?
abstract: OBJECTIVE
  The objective of this study was to analyze the population incidence of retinopathy of prematurity treatment in Denmark in the 10-year period from 1996 to 2005.
  
  
  METHODS
  Patient charts of infants treated for retinopathy of prematurity and the national birth registry provide information about neonatal parameters. These parameters, along with birth in the latter half of the period (2001-2005), were analyzed as risk factors for retinopathy of prematurity. The national registry for blind and visually impaired children was accessed to obtain information about visual impairment attributable to retinopathy of prematurity in both treated and untreated infants.
  
  
  RESULTS
  The study population consisted of 5467 Danish preterm infants born in 1996 to 2005, with a gestational age of < 32 weeks, who survived for > or = 5 postnatal weeks; 2616 were born in 1996 to 2000, and 2851 were born in 2001 to 2005. The incidence of treated retinopathy of prematurity cases increased significantly from 1.3% in 1996 to 2000 to 3.5% in 2001 to 2005. Significant risk factors for retinopathy of prematurity treatment were low gestational age, small for gestational age, male gender, and multiple birth. Other, yet unknown factors contributed to the increased incidence in the latter half of the period. Of the study population, 0.6% were registered as visually impaired because of retinopathy of prematurity within 2 years after birth (early-detected visual impairment). The incidences were not significantly different between 1996 to 2000 and 2001 to 2005. Of all of the early-detected, visually impaired children, 16% had not been treated for retinopathy of prematurity and were considered screening failures.
  
  
  CONCLUSIONS
  The incidence of retinopathy of prematurity treatment in Denmark has more than doubled during the past half-decade. This increase could not be fully explained by increased survival rates for the infants or by changes in the investigated neonatal risk factors.
authors.affiliation: Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark. carinaslidsborg@hotmail.com
authors.forename: Carina
authors.initials: C
authors.lastname: Slidsborg
authors.forename: Henrik Bom
authors.initials: HB
authors.lastname: Olesen
authors.forename: Peter Koch
authors.initials: PK
authors.lastname: Jensen
authors.forename: Hanne
authors.initials: H
authors.lastname: Jensen
authors.forename: Kamilla Rothe
authors.initials: KR
authors.lastname: Nissen
authors.forename: Gorm
authors.initials: G
authors.lastname: Greisen
authors.forename: Steen
authors.initials: S
authors.lastname: Rasmussen
authors.forename: Hans Callø
authors.initials: HC
authors.lastname: Fledelius
authors.forename: Morten
authors.initials: M
authors.lastname: la Cour
mesh_terms: D015331:Cohort Studies; D017679:Cryotherapy / Q000379:methods; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D008028:Light Coagulation / Q000379:methods; D016015:Logistic Models; D008297:Male; D011336:Probability; D012042:Registries; D012178:Retinopathy of Prematurity / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D014792:Visual Acuity; D014821:Vitrectomy / Q000379:methods