Objective: To determine the current incidence of retinopathy of prematurity (ROP) in New York state.
Design: Population-based cohort study.
Participants: Newborn infants (15 691) with initial hospital length of stay >28 days and date of discharge from January 1, 1996, to December 31, 2000. Subjects were identified from the New York Statewide Planning and Research Cooperative System (SPARCS) database, which contains information about every patient hospitalized in New York during this period.
Methods: Demographic and clinical information about eligible infants was abstracted by searching the SPARCS database. Patients with a discharge diagnosis of ROP or who underwent laser retinal photocoagulation, scleral buckle, or pars plana vitrectomy were identified by searching for appropriate discharge and procedure codes. Incidence of ROP in the study population was determined and analyzed on the basis of birth weight.
Main outcome measures: Incidence of any ROP, laser photocoagulation, scleral buckle, and pars plana vitrectomy in study population.
Results: On the basis of SPARCS coding, the overall incidence of any ROP among all newborn infants in New York state during the study period was 0.2% (2284 of 1 167 427), or 1 in 511. The incidence of any ROP in the study population of newborns with initial hospital length of stay >28 days was 20.3% (2152 of 10 596) among infants with birth weight <1500 g and 27.3% (1839 of 6745) among infants with birth weight <1200 g. Among study patients with any ROP, the proportion who underwent laser photocoagulation during initial hospital stay was 9.5% (218 of 2284), and the proportion who underwent scleral buckle or vitrectomy surgery was 0.5% (12 of 2284). Seventeen study newborns with birth weight > or =2000 g had a discharge diagnosis of ROP, although none of these patients required laser or incisional surgery during hospitalization.
Conclusions: This study involves the largest known cohort of newborns that has been analyzed for ROP. The incidence of ROP in this study is lower than results from previous multicenter clinical trials. However, the diagnosis of ROP in 17 study newborns with birth weight > or =2000 g deserves further investigation and may have implications for ROP screening protocols.