Abstract: FR-PO0445
Validity of Phosphorus Intake Assessment Tools in CKD and Dialysis Populations
Session Information
- Dialysis: Measuring and Managing Symptoms and Syndromes
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Alvarez-Elias, Ana Catalina, Fresenius Medical Care, Clinical Research, Global Medical Office, North America, New York, New York, United States
- Cromm, Krister, Fresenius Medical Care Deutschland GmbH, Global Medical Office, Bad Homburg, Frankfurt, Hessen, Germany
- Pham, Ngoc, Fresenius Medical Care Deutschland GmbH, Global Medical Office, Bad Homburg, Frankfurt, Hessen, Germany
- Strippoli, Giovanni, Department of Precision and Regenerative Medicine and Jonian Area (Dimepre-J), University of Bari, Bari, Apulia, Italy
Background
Accurate dietary assessment of phosphorus intake is essential for managing hyperphosphatemia in chronic kidney disease. Clinicians often rely on self-reported data which may be unreliable. This review summarizes evidence on the realiability and validity of phosphorus intake assessment tools in patients with chronic kidney disease or ondergoing dialysis.
Methods
We performed a literature search in PubMed and Google Scholar from inception to April 2025, using MeSH terms for “food frequency”, “dietary recall”, “phosphate”, “chronic kidney disease”, “end-stage kidney disease” “dialysis”, “surveys” and “questionnaires”. We included studies with assessment of either validity or reliability of the tools. Data was summarized descriptively reporting quantitative measurements.
Results
We identified 5 studies (543 patients). Key characteristics of the studies included and their implications for clinical use are reported in the table. All studies were from different countries. Participants were older than 18 years. Four studies included people on at least one dialysis modality, while one study only included people with moderate to advanced chronic kidney disease but no dialysis patients. The tools comprised food frequency questionnaires (FFQs), short FFQs (SFFQs), and phosphorus knowledge instruments combined with food intake report. Two studies used self-administered tools. All studies found weak to moderate correlations between dietary intake and serum phosphorus or nutrient biomarkers, with questionnaire formats ranging from 31 to 154 food items.
Conclusion
All tools showed accuracy limitations, especially among elderly or multi-morbid patients. Literature addressing the accuracy of self-reported intake warns of systematic underreporting, notably in patients with advanced disease or lower health literacy. This implies a need for cautious interpretation of patient-reported phosphorus intake and consideration of supplemental strategies—like biochemical monitoring, dietitian interviews, or digital tracking—for a more accurate evaluation. We are converting this analysis into a systematic review using rigorous, evidence-based methods.