Registered Dietitian Time Requirements in the Modification of Diet in Renal Disease Study

Abstract

Objective To assess time expended by registered dietitians to conduct clinical and research activities during the Modification of Diet in Renal Disease (MDRD) Study. Design Two randomized, controlled clinical trials among persons with diminished levels of renal function using a factorial design to evaluate effects of dietary protein restriction and blood pressure control on progression of renal disease. In study A, subjects with moderate renal insufficiency were randomly assigned to a diet of usual protein (1.30 g/kg per day) or low protein (0.58 g/kg per day) and to either a usual or low blood pressure level. Study B involved subjects with advanced renal insufficiency who were randomly assigned to the low-protein diet or a very-low-protein prescription (0.28 g/kg per day) with a ketoacid-amino acid supplement (0.28 g/kg per day) and to either the usual or low blood pressure level. A time-log form designed by MDRD Study dietitians was completed for each participant at 36 monthly follow-up visits. Setting Fifteen clinical centers throughout the continental United States. Subjects Eight hundred forty adults aged 18 to 70 years with chronic renal diseases participated in the MDRD Study — 585 in study A and 255 in study B. Statistical analyses One-way analyses of variance and t tests were used to evaluate significant time requirement differences by diet groups, diagnosis, and sociodemographics. Results Mean total time for all participant visits declined from 183+1 minutes per visit during months 1 through 4 to 116±41 minutes per visit during months 25 through 36. Significantly more dietitian time was required for participants consuming the low-protein and very-low-protein diets than for those consuming the usual-protein diet. Age, gender, race, marital status, and renal diagnosis did not influence time requirements. A significant inverse association between education level and dietitian time was apparent. Applications The MDRD Study time-log data should be useful when determining staffing patterns for nutrition management in clinical and research settings. J Am Diet Assoc. 1995; 95:1307-1312.