Relative and Absolute Reliability of Physical Function Measures in People with End-Stage Renal Disease

Abstract

Purpose: End-stage renal disease (ESRD) is a condition affecting multiple physiological systems, leading to a decline in physical function. Effectiveness of therapeutic interventions in people with ESRD has been assessed using various functional and activity outcome measures. The purpose of this study was to determine the relative and absolute reliability of the 6-minute walk test (6MWT), timed sit-to-stand in 30 seconds (TSS30), and maximal and adjusted activity scores (MAS-HAP, AAS-HAP) of the Human Activity Profile (HAP) in people with ESRD. Method: A convenience sample of 25 participants (67.2e14.2 years) was recruited from an outpatient dialysis unit. Relative reliability was determined using the intraclass correlation coefficient (ICC 2,1 ), and absolute test-retest reliability with the standard error of measurement (SEM) and minimal detectable change at the 95% confidence interval (MDC 95 ) statistics, respectively. The test-retest interval was 1 week. Results: Relative reliability (ICC 2,1 ) was 0.93 for both the 6MWT and the TSS30, 0.92 for the AAS-HAP, and 0.76 for the MAS-HAP. Absolute reliability (SEM and MDC 95 ) values for the 6MWT, AAS-HAP, and TSS30 were 28 m and 77 m, 4.1 and 11.4, and 0.9 and 2.6 repetitions, respectively. Conclusions: Our results suggest that the 6MWT, TSS30, and AAS-HAP are reliable physical function and activity outcome measures in people with ESRD. However, the magnitude of the absolute reliability statistics suggests significant within-participant variability on repeat testing in this population.Key Words: end-stage renal disease, Human Activity Profile, reliability, 6-minute walk test, timed-sit-to-stand

Morphological, Electrophysiological, and Metabolic Characteristics of Skeletal Muscle in People with End-Stage Renal Disease: A Critical Review

“…[7][8][9] Several reviews have confirmed the presence of muscle weakness and reduced physical function in this population. 2,[10][11][12] A similar report of reductions in physical function in a Canadian ESRD/HD sample was reported by Overend et al; 13 mean scores of the physical function measures were in the tenth percentile of established normative values for community-dwelling residents between 65 and 85 years of age. 14 Observations of progressive proximal muscle weakness in people with ESRD/HD by Floyd et al, 15 Lazaro and Kirshner, 16 and others were ascribed to myopathy (skeletal muscle damage).…”

Reliability and screening ability of the StarT Back screening tool in patients with low back pain in physiotherapy practice, a cohort study

“…Furthermore, Bland and Altman plots were used to evaluate limits of agreement between test and retest [24]. The absolute reliability [25] was presented as the smallest detectable change (SDC) using the standard error of measurement SEM = SD diff /√2 and the SDC = 1,96*√2 *SEM. SDC reflects the smallest change in score that can be interpreted as change above measurement error in an individual.…”

The deterioration in physical function of hemodialysis patients

“…51 As such, it is likely that some of the change in performance may be attributed to participant familiarisation with physical performance measures. First, though every effort was made to ensure consistency between measures across all 15 hemodialysis units such as chair heights and body-weight scales, variations in floor surface were unable to be accounted for.…”