Background/Purpose: Assessment of self-reported physical functioning is common in SLE and essential for high-quality SLE care. However, because many factors may influence self-reported physical function (individual’s perceptions of physical abilities and limitations), it may be an imperfect measure of physical performance (observations of physical function). We leveraged two adult population-based SLE cohorts with simultaneous assessments of self-reported (perceived) physical function and physical performance to estimate the concordance of these measures and explore the factors associated with discordance.

Methods: Cross-sectional data on perceived physical function [Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) 10a or 10b, both reported as T-scores (population mean = 50, SD = 10)] and physical performance [Short Physical Performance Battery (SPPB; score range: 0–12, higher scores = better performance on balance, gait speed, and chair stand tasks)] and were obtained from Approaches to Positive, Patient-centered Experiences of Aging with Lupus (APPEAL; 10/2019–5/2022) and California Lupus Epidemiology Study (CLUES; 1/2018–9/2019). We assessed concordance between quartiles of PROMIS PF and SPPB scores and the factors associated with discordant (³2 quartiles different) vs. concordant scores using crude multinomial logistic regression.

Results: Among 619 participants (mean age, 46; 91% female; 13% Asian, 61% Black, 11% Hispanic, 14% White), mean PROMIS PF and SPPB scores were 41 and 9, respectively. Percent agreement between quartiles of SPPB and PROMIS PF scores was 37% (Figure 1). Overall, 478 individuals had concordant scores (77%), while the remaining 23% had discordant scores: 69 (11%) with SPPB score > PROMIS PF score and 72 (12%) with SPPB score < PROMIS PF score. Higher BMI and disease activity were associated with 18% and 42% higher relative risk of discordant scores with SPPB > PROMIS PF (vs. concordant); in contrast, higher disease activity and depressive symptoms were associated with 62% and 42% lower relative risk of discordant scores with SPPB < PROMIS PF (vs. concordant) (Table 1). Higher coping efficacy scores were associated with 9% lower and 19% higher risk of discordant scores with SPPB > PROMIS PF and SPPB < PROMIS PF, respectively. Patient-reported pain, sleep problems, and fatigue were associated with 1.4- to 2.0-fold higher risk of discordant scores with SPPB > PROMIS PF (not statistically significant) and 40-60% lower risk of discordant scores SPPB < PROMIS PF.

Conclusion: In this large, cross-cohort analysis, nearly one-quarter had discordant perceived physical function and physical performance scores. Higher BMI, disease activity, depressive symptoms, and other patient-reported outcomes such as pain and fatigue were generally associated with higher risk of underreporting physical functioning relative to actual physical performance (SPPB score > PROMIS PF score), as well as with a lower risk of overreporting functioning (SPPB score < PROMIS PF score). These results suggest that physical performance, at least in terms of lower extremity mobility, may not be reliably assessed from self-reported physical function in this population.

« Back to ACR Convergence 2025

ACR Meeting Abstracts - https://acrabstracts.org/abstract/concordance-of-self-reported-physical-functioning-and-physical-performance-in-sle-a-cross-cohort-analysis/