1 Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois2Center for Healthcare Studies, Feinberg School of Medicine, Northwestern University, Chicago, Illinois3Veterans Affairs Health Services Research and Development Service, Chicago, Illinois.
2 Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, Florida.
3 Center for Healthcare Studies, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
4 Division of Ophthalmology, Alpert Medical School, Brown University, and Rhode Island Hospital, Providence, Rhode Island6Section of Ophthalmology, Providence VA Medical Center, Providence, Rhode Island.