Design and development of a dialysis food frequency questionnaire.

OBJECTIVES Periodic assessment of dietary intake across a given dialysis population may help to improve the clinical outcomes related to nutrients such as dietary protein, phosphorus, or potassium. Although dietary recalls and food records are used to assess dietary intake at individual level and over shorter periods, food frequency questionnaires (FFQ) are used to rank subjects of a given population according to their nutrient intake over longer periods. DESIGN To modify and refine the conventional Block FFQ to develop a specific FFQ for dialysis patients. SETTING A total of 8 DaVita outpatient dialysis clinics in Los Angeles area, which participated in the "Nutrition and Inflammation in Dialysis Patients" study. PATIENTS The study included 154 patients undergoing maintenance hemodialysis (MHD). MAIN OUTCOME MEASURE Dietary intake of participating MHD patients using a 3-day food record, supplemented by a person-to-person dietary interview, to capture food intake over the last hemodialysis treatment day of the week and the 2 subsequent nondialysis days. RESULTS Analyses of the food records identified the key contributors to the daily nutrient intake in the 154 participating MHD patients. A "Dialysis-FFQ" was developed to include approximately 100 food items representing the total food intake of 90% of the patients of the "Nutrition and Inflammation in Dialysis Patients" study population. Distinctions were made in several food items on the basis of key nutritional issues, such as protein, phosphorus, and potassium, in dialysis patients. CONCLUSIONS We have developed a "Dialysis FFQ" to compare and rank dialysis patients according to their diverse nutrient intake. Although the Dialysis-FFQ may be a valuable tool to compare dialysis patients and to identify those who ingest higher or lower amounts of a given nutrient, studies are needed to examine the utility of the Dialysis-FFQ for nutritional assessment of dialysis patients.