Impact of measurement timing on reproducibility of testing among haemodialysis patients

Abstract

Accurate evaluation of physical function in patients undergoing haemodialysis is crucial in the analysis of the impact of exercise programs in this population. The aim of this study was to evaluate the reproducibility of several physical functional tests, depending on the timing of their implementation (before the HD session vs. non-HD days). This is a prospective, non-experimental, descriptive study. Thirty patients in haemodialysis were evaluated twice, 1 week apart. The test session was performed before the haemodialysis session started and a retest was performed in non-dialysis day. The testing battery included the short physical performance battery, sit-to-stand tests, 6 min walk test, one-leg stand test, timed up and go, and handgrip strength with and without forearm support. The intra-rater reproducibility was determined by the intraclass correlation coefficients and the agreement was assessed by Bland–Altman analysis. The intraclass correlation coefficients values ranged from 0.86 to 0.96, so that all tests showed good to very good relative reliability. The mean differences between trials of sit to stand 10 and 60, timed up and go and all the handgrip tests were close to zero, indicating no systematic differences between trials. Large range of values between trials was observed for the 6 min walk test, gait speed, one-leg stand test and short physical performance battery, indicating a systematic bias for these four tests. In conclusion, the sit to stand 10 and 60, timed up and go and handgrip tests had good to excellent test–retest reliability in measuring physical function in different dialysis days of patients undertaking haemodialysis. The minimal detectable change values are provided for this population. Bias were found for the 6 min walk test, gait speed, Short physical performance battery or one-leg stand test when the testing day changed.

Measurement properties of performance-based measures to assess physical function in chronic kidney disease: recommendations from a COSMIN systematic review

“…Reliability was reported in three studies and showed excellent ICC values (0.89–0.96) [ 27–29 ]. Two studies reported on measurement error with a SEM ranging from 1.5 to 2.3 kg in people on HD [ 28 , 29 ]. The minimal detectable change, 90% confidence level (MDC90) ranged between 3.4 and 5.5 kg.…”

“…In people with CKD and receiving HD, data showed that the Six-minute walk test (6MWT) correlated with maximum oxygen uptake (VO 2max ; r between 0.62 and 0.70) [ 35 , 36 ], and low score was predictive of mortality [ 32–34 ], hospitalizations [ 33 ], cardiovascular events [ 33 ], technique failure amongst PD patients [ 30 ], increased fracture risk [ 31 ] and lower chance of transplantation [ 32 ]. Four studies showed excellent reliability [ 18 , 2 8 , 29 , 37 ]. Measurement error was consistent (28.0–29.5 m) in an adult HD population [ 28 , 29 , 37 ] and amongst a mixed pediatric group of CKD, HD and transplant patients (21.8 m) [ 18 ].…”

Minimal detectable change of gait and balance measures in older neurological patients: estimating the standard error of the measurement from before-after rehabilitation data thanks to the linear mixed-effects models

“…For example, when variability increases as the measured values increase, as is always the case for TTD (e.g. [ 56 ]). , the data are heteroscedastic [ 57 ].…”

A dataset of the effects of therapeutic exercise programs on physical function in patients undergoing hemodialysis

“…The dataset was collected between November 2015 and May 2016 and it includes a document with two Excel spreadsheets that present raw data involving the results for the assessments prior to and after the therapeutic exercise intervention. The data included results from the following tests: Short Performance Physical Battery Test [3] , that is a combination of physical tests that assess balance, gait speed and lower limb functional strength that scored over a total of 12 points, Timed-Up and Go [ 4 , 5 ], that is a mobility test, Sit-to stand-to sit 10 and 60 [ 6 , 7 ], that assess resistance and strength of the lower limb muscles, One-Leg Heel-Rise [6] , that assesses the strength and endurance of the triceps surae, and handgrip strength [6] , assessed through dynamometry.…”

“…After that, the Timed-Up and Go [ 4 , 5 ] test was performed, registering the time (in seconds) the patient required to complete the test three consecutive times. After that participants performed the Sit-to stand-to sit tests [ 6 , 7 ].…”