256 subspecialty medical practices in 5 large U.S. cities in 4 states (Atlanta, Georgia; Dallas and Houston, Texas; Portland, Oregon; and Boston, Massachusetts). The study included 2 groups of subspecialties: those where transfer from a wheelchair to an examination table is required for adequate care (endocrinology, gynecology, orthopedic surgery, rheumatology, and urology) and those where transfer might not be necessary (otolaryngology, ophthalmology, and psychiatry).