2528 Comparing patient-reported and performance-based physical function assessments in hemodialysis: insights from the CONVINCE trial

• Published in: Nephrology, dialysis, transplantation dialysis, transplantation, 2024-05, Vol.39 (Supplement_1)
• Main Authors: Liegl, Gregor, Fischer, Felix, Canaud, Bernard, Woodward, Mark, Barth, Claudia, Davenport, Andrew, Strippoli, Giovanni, Hegbrant, Jörgen, Cromm, Krister, Blankestijn, Peter J, Fischer, Kathrin I, Rose, Matthias
• Format: Article
• Language: English
• ISSN: 0931-0509; 1460-2385
• DOI: 10.1093/ndt/gfae069.1560

Abstract Background and Aims Physical function is a crucial outcome in nephrology. In alignment with the Patient-Reported Outcomes Measurement Information System (PROMIS) Initiative, physical function is characterized as the ability to execute activities involving physical actions, ranging from self-care to more complex activities, such as social activities. This definition of physical function spans various domains of the International Classification of Functioning, Health, and Disability (ICF). The assessment of physical function commonly employs two distinct approaches, patient-reported outcomes (PRO) and observed performance outcomes (PerfO). PRO and PerfO assessments have distinct advantages and limitations and were found to correlate only moderately, adding complexity to cross-instrument outcome comparisons and interpretation. Despite this, there is limited understanding of the factors contributing to the discordance between PRO and PerfO assessments in patients with kidney disease. In this study, we applied a previously established common T-score metric for patient-reported and performance-based physical function to compare patterns of associations with potential laboratory-based, psychosocial, sociodemographic, and health-related determinants in hemodialysis patients. Method Cross-sectional data from the baseline assessment of the CONVINCE trial (N = 1,132), a multinational randomized controlled trial comparing high-dose hemodiafiltration with high-flux hemodialysis, were analysed. To investigate the relationships between potential determinants and performance-based versus patient-reported physical function, we performed multiple linear regression analysis. Dependent variables were standardized T-scores derived from the PROMIS physical function short-form 4a (PRO) and the Physical Performance Test (PerfO). Both measures assess a generic concept of physical function. We compared the effect sizes of each potential determinant in the multiple regression model using partial f2 values, with thresholds of 0.02, 0.15, and 0.35 denoting small, medium, and large effects. Results Both, PerfO and PRO exhibited significant associations with a laboratory marker-based indicator of muscle mass (simplified creatinine index), albeit with relatively small effects (partial f² of 0.04 and 0.05, respectively). None of the other laboratory measures investigated in this study showed any relevant associations with physical functioning. Age demonstrated a negative associat