Abstract: FR-PO1025
Construct Validation of an Item Response Theory-Derived Intradialytic Symptom Score Using KDQoL-36 and Recovery Time
Session Information
- Hemodialysis: Clinical Challenges, Patient-Centered Outcomes, and Quality of Life
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Ion Titapiccolo, Jasmine, Fresenius Medical Care Italia SpA, Palazzo Pignano, Lombardia, Italy
- Flythe, Jennifer E., The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Bellocchio, Francesco, Fresenius Medical Care Italia SpA, Palazzo Pignano, Lombardia, Italy
- Stuard, Stefano, Fresenius Medical Care Italia SpA, Palazzo Pignano, Lombardia, Italy
- Goethel-Paal, Berit, Fresenius Medical Care AG, Bad Homburg, HE, Germany
- Rincón, Abraham, Fresenius Medical Care AG, Bad Homburg, HE, Germany
- Baró-Salvador, Maria-Eva, Fresenius Medical Care AG, Bad Homburg, HE, Germany
- Guinsburg, Adrian M., Fresenius Medical Care AG, Bad Homburg, HE, Germany
- Fazendeiro Matos, Joao, Fresenius Medical Care AG, Bad Homburg, HE, Germany
- Ribeiro, Ana Raquel Ferreira, Fresenius Medical Care AG, Bad Homburg, HE, Germany
- Usvyat, Len A., Renal Research Institute, New York, New York, United States
- Neri, Luca, Fresenius Medical Care Italia SpA, Palazzo Pignano, Lombardia, Italy
Background
Intradialytic symptoms are common but often underrecognized and undertreated, despite their impact on treatment tolerance and patient well-being. A standardized symptom score could help clinicians quantify and monitor intradialytic symptom burden. Following prior evaluation of the dimensionality, internal consistency, and IRT model fit of the 12-item Intradialytic Symptoms (IS) survey [Ion Titapiccolo et al, ASN 2025], we sought to examine the construct validity of the item response theory (IRT)-derived IS score (IRT-IS) through its associations with KDQoL-36 and post-dialysis recovery time.
Methods
We analyzed data from 1419 hemodialysis patients treated at NephroCare dialysis centers in Czech Republic, France, Italy, Spain, and United Kingdom who completed the IS and KDQoL-36 surveys on the same day. The surveys were split into modeling (70%) and testing (30%) samples. Using a unidimensional 2-parameter logistic IRT structure [Ion Titapiccolo et al, ASN 2025], we fitted the model using the modeling sample surveys and then estimated IS T-scores in the testing sample surveys. We assessed associations between the IRT-IS score and KDQoL-36 scales using Pearson correlations, and between the IRT-IS score and recovery time after the last dialysis session (few minutes,~1 hour,1-3 hours,3-8 hours,>8 hours) using Spearman and Kendall correlations and ordinal logistic regression.
Results
Higher IRT-IS scores were associated with worse KDQoL-36 scores: symptoms/problems r=-0.54 (n=410), effects of kidney disease r=-0.36 (n=407), burden of kidney disease r=-0.31 (n=369), physical composite r=-0.25 (n=390), and mental composite r=-0.23 (n=390) (all p<0.001), supporting convergent validity, particularly for symptoms/problems burden. Higher IRT-IS scores were also significantly associated with longer recovery time (n=420). For the reference IRT-IS score, Spearman’s rho was 0.218 and Kendall’s tau was 0.161. In ordinal logistic regression models, higher IRT-IS scores were associated with greater odds of longer recovery time (reference score OR 1.03, 95% CI 1.02-1.05), indicating that greater intradialytic symptoms/problems burden tracked with delayed recovery.
Conclusion
IRT-derived IS scores showed consistent associations with KDQoL-36 and recovery time, supporting their construct validity, clinical interpretability, and potential use to identify high-burden patients and monitor intervention response.