Registered dietitian time requirements in the Modification of Diet in Renal Disease Study.

Today's intense focus on health care reform makes cost-effectiveness of delivering health programs a timely issue. More than ever, health care professionals must justify their roles and importance in the provision of optimal care to the public through health delivery systems. Registered dietitians are no exception.

The American Dietetic Association began to evaluate costs and benefits of dietitian activities in the 1970s and has continued to strongly encourage work related to this area among professionals in the organization (1-3). A recent evaluation found that most dietitians recognize the importance of cost-effectiveness and cost-benefit analyses but do not apply them in practice or use them for research purposes (4). A possible explanation is that practicing dietitians are not familiar with ways to incorporate research methodologies into their day-to-day clinical work.

Knowledge of professional time required to deliver nutrition programs is essential when establishing adequate staffing patterns and determining costs. A major contribution to this important area from the Modification of Diet in Renal Disease (MDRD) Study was a substudy that documented dietitian time requirements according to various types of activities necessary to effectively achieve the study's nutritional objectives.

Because low-protein diets are routinely used to manage symptoms of pre-end-stage renal disease and have been hypothesized to delay the time until dialysis is indicated, there has been great interest in the assessment of the costs of this medical nutrition therapy (5-8). Such data provide descriptive information about dietitian activities and costs. Moreover, assessment was considered vital to justify involvement of dietitians in the management of renal disease.

This study component was designed and implemented by MDRD Study dietitians. We report the process of designing the time log and the estimated time expenditures of dietitians to accomplish their nutrition-related responsibilities.

METHODS

Overview

The MDRD Study included two randomized, controlled clinical trials that used a two-by-two factorial design to evaluate the effects of three dietary protein prescriptions and two blood pressure levels on the progression of renal disease as measured by change in glomerular filtration rates over time. The study was conducted at 15 clinical centers throughout the continental United States and involved 840 men and women with chronic renal disease, aged 18 to 70 years. Study A consisted of 585 participants whose glomerular filtration rates were in the range of 25 to 55 mL/min per 1.73 [m.sup.2]; the participants were randomly assigned to either a dietary protein prescription of 1.3 g/kg per day (usual protein) or 0.58 g/kg per day (low protein) and to a blood pressure level of either 107 mm Hg mean arterial pressure (usual) or 92 mm Hg mean arterial pressure (low). Study B involved 255 participants with glomerular filtration rates in the range of 13 to 24 mL/min per 1.73 [m.sup.2]; these participants were randomly assigned to the low-protein diet or a dietary protein prescription of 0.28 g/kg per day (very low protein) with a ketoacid-amino acid supplement (0.28 g/kg per day) and to either the usual or low blood pressure level. Details regarding the study design, recruitment, baseline data, and final results are published elsewhere …