title: International variations and trends in the treatment for retinopathy of prematurity.
abstract: To compare the rates of retinopathy of prematurity (ROP) and treatment of ROP by laser or intravitreal anti-vascular endothelial growth factor among preterm neonates from high-income countries participating in the International Network for Evaluating Outcomes (iNeo) of neonates.
  
  
  
  A retrospective cohort study was conducted on extremely preterm infants weighing <1500 g at 240to 276weeks' gestation who were admitted to neonatal units in Australia/New Zealand, Canada, Finland, Israel, Japan, Spain, Sweden, Switzerland, Tuscany (Italy) and the UK between 2007 and 2013. Pairwise comparisons of ROP treatment in survivors between countries were evaluated by Poisson and multivariable logistic regression analyses after adjustment for confounders. A composite outcome of death or ROP treatment was compared between countries using logistic regression and standardised ratios.
  
  
  
  Of 48 087 infants included in the analysis, 81.8% survived to 32 weeks postmenstrual age, and 95% of survivors were screened for ROP. Rates of any ROP ranged from 25.2% to 91.0% in Switzerland and Japan, respectively, among those examined. The overall rate of those receiving treatment was 24.9%, which varied from 4.3% to 30.4%. Adjusted risk ratios for ROP treatment were lower for Switzerland in all pairwise comparisons, whereas Japan displayed significantly higher ratios. Comparisons of the composite outcome between countries revealed similar, but less marked differences.
  
  
  
  Rates of any ROP and ROP treatment varied significantly between iNeo members, while an overall decline in ROP treatment was observed during the study period. It is unclear whether these variations represent differences in care practices, diagnosis and/or treatment thresholds.
authors.affiliation: Australia and New Zealand Neonatal Network, Department of Paediatrics, University of Otago, Christchurch, New Zealand.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Darlow
authors.affiliation: Australian and New Zealand Neonatal Network, Royal Hospital for Women, National Perinatal Epidemiology and Statistic Unit, University of New South Wales, Randwick, Australia.
authors.forename: Kei
authors.initials: K
authors.lastname: Lui
authors.affiliation: Neonatal Research Network Japan, Maternal and Perinatal Center, Tokyo Women's Medical University, Kawadacho, Shinjuku, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kusuda
authors.affiliation: Israel Neonatal Network, Gertner Institute for Epidemiology and Health Policy Research, Sheba Medical Centre, Tel Hashomer, Israel.
authors.forename: Brian
authors.initials: B
authors.lastname: Reichman
authors.affiliation: Swedish Neonatal Quality Register, Department of Pediatrics/Neonatal Services, Umeå University Hospital, Umeå, Sweden.
authors.forename: Stellan
authors.initials: S
authors.lastname: Håkansson
authors.affiliation: Swiss Neonatal Network, Department of Neonatology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse, Zurich, Switzerland.
authors.forename: Dirk
authors.initials: D
authors.lastname: Bassler
authors.affiliation: UK Neonatal Collaborative, Neonatal Data Analysis Unit, Section of Neonatal Medicine, Department of Medicine, Imperial College London, Chelsea and Westminster Hospital campus, London, UK.
authors.forename: Neena
authors.initials: N
authors.lastname: Modi
authors.affiliation: Department of Paediatrics, Mount Sinai Hospital and University of Toronto, Toronto, Ontario, Canada.|Canadian Neonatal Network, Maternal-Infant Care Research Centre, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Shoo K
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Finnish Medical Birth Register and Register of Congenital Malformations, Department of Pediatrics, Turku Univeristy Hospital, Kiinamyllynkatu, Turku, Finland.
authors.forename: Liisa
authors.initials: L
authors.lastname: Lehtonen
authors.affiliation: Spanish Neonatal Network, Health Research Institute La Fe, Avenida Fernando Abril Martorell, Valencia, Spain.
authors.forename: Maximo
authors.initials: M
authors.lastname: Vento
authors.affiliation: Department of Paediatrics, Mount Sinai Hospital and University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Isayama
authors.affiliation: Swedish Neonatal Quality Register, Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sjörs
authors.affiliation: Finnish Medical Birth Register and Register of Congenital Malformations, Department of Pediatrics, Turku Univeristy Hospital, Kiinamyllynkatu, Turku, Finland.
authors.forename: Kjell K
authors.initials: KK
authors.lastname: Helenius
authors.affiliation: Swiss Neonatal Network, Department of Neonatology, University Hospital Zurich, University of Zurich, Frauenklinikstrasse, Zurich, Switzerland.
authors.forename: Mark
authors.initials: M
authors.lastname: Adams
authors.affiliation: TIN Toscane Online, Unit of Epidemiology, Meyer Children's University Hospital, Viale Pieraccini, Florence, Italy.|Regional Health Agency, Via Pietro Dazzi, Florence, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Rusconi
authors.affiliation: Neonatal Research Network Japan, Department of Social Medicine, National Center for Child Health and Development, Okura, Setagaya, Tokyo, Japan.
authors.forename: Naho
authors.initials: N
authors.lastname: Morisaki
authors.affiliation: Department of Paediatrics, Mount Sinai Hospital and University of Toronto, Toronto, Ontario, Canada.|Canadian Neonatal Network, Maternal-Infant Care Research Centre, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Prakesh S
authors.initials: PS
authors.lastname: Shah
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D005260:Female; D005865:Gestational Age; D014943:Global Health; D006801:Humans; D007223:Infant; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D053685:Laser Therapy / Q000706:statistics & numerical data / Q000639:trends; D016015:Logistic Models; D008297:Male; D013508:Ophthalmologic Surgical Procedures / Q000706:statistics & numerical data / Q000639:trends; D009885:Ophthalmology / Q000706:statistics & numerical data / Q000639:trends*; D012178:Retinopathy of Prematurity / Q000453:epidemiology / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies
chemical_list: D020533:Angiogenesis Inhibitors
keywords: Child health (paediatrics); Epidemiology; Retina