We propose to conduct the full-scale clinical trial of the Modification of Diet in Renal Disease (MDRD) Study at Vanderbilt in accordance with the Phase III Study Protocol and Manuals of Operations. Utilizing our experience as members of the MDRD Steering Committee in Phase I-Planning and Phase II-Pilot Study, we propose to enroll 40 patients during the 21 month recruitment period, at least 20 each in Study A and Study B as defined by the Protocol. We propose a Study team organization and staffing plan to accomplish that goal, based on our successful Phase II recruitment of 19 patients into the Baseline period and 12 patients into Follow-up (Study A:9; Study B:3). To begin a preliminary recruitment survey, 10 local nephrologists, two other practitioners, and the single preeminent HMO in the area have been contacted to date, and the patient flow in the vanderbilt and VA Renal and Diabetic Clinics have been reviewed. Our current estimate of 276 eligible patients and a potential total accession rate of 343 new patients in 21 months should produce (in parallel to Phase II experience) at least 124 patients who are eligible and not excluded. In addition, a new, specially organized Center for the Control of Progressive Renal Disease will begin on 7/1/87 to attract potential candidates from within Vanderbilt, from Middle Tennessee and surrounding states, in which "catchment area" are an estimated 2000 patients with known or unrecognized chronic renal disease at varying degrees of chronic renal failure. Protocol implementation involves continuation of successful methods learned in Phase II to assure adherence of both patients and project staff to protocol requirements, including adequate dietitian time for intensive instruction and counseling, close communications among project staff, and supportive relationships between project personnel and each enrolled patient.