1. Center for Quality of Care and Utilization Studies (a Veterans Affairs Health Services Research and Development Field Program), Houston, Tex, the VA Medical Center, Houston, Tex and the Baylor College of Medicine, Houston, Tex,
2. Center for Quality of Care and Utilization Studies (a Veterans Affairs Health Services Research and Development Field Program), Houston, Tex, the VA Medical Center, Houston, Tex and the Baylor College of Medicine, Houston, Tex