A Comparison of 3 Methodological Approaches to Defining Major Clinically Important Improvement of 4 Performance Measures in Patients With Hip Osteoarthritis

Abstract

For rehabilitation professionals engaged in the treatment of osteoarthritis (OA), it is standard practice to perform objective assessments of physical function (using both physical performance and self-report measures) to obtain a picture of patient status. These assessments also serve as a baseline value for estimating changes (treatment effects) over time. While reliability and validity of some commonly used physical performance measures have been investigated in an OA population, most require further research regarding clinical utility and responsiveness. 14 Physical performance measures have often been criticized, as detailed testing of their measurement properties has not been extensively reported. 14,22,33 Measures of responsiveness have commonly been reported as statistically significant change scores, which are useful in establishing the threshold of change needed beyond measurement error. 10 Investigation of minimal clinically important differences (MCIDs) of physical performance measures is warranted, as these have become commonly used outcome measures in the treatment of OA. 8,12,17,[35][36][37] At present, the responsiveness (in terms of MCID) of the timed up-and-go (TUG) test, 40-meter self-paced walk test (40-m SPWT), 30-second chair stand (30 CST), and 20-cm step test has not been investigated in T T STUDY DESIGN: Prospective cohort study. T T OBJECTIVES:To establish the major clinically important improvement (MCII) of the timed upand-go test (TUG), 40-meter self-paced walk test (40-m SPWT), 30-second chair stand (30 CST), and a 20-cm step test in patients with hip osteoarthritis (OA) undergoing physiotherapy treatment. As a secondary aim, a comparison of methods was employed to evaluate the effect of method on the reported MCII. T T BACKGROUND: Minimal clinically importantdifference scores are commonly used by rehabilitation professionals to determine patient response following treatment. A gold standard for calculating MCII has yet to be determined, which has resulted in problems of interpretation due to varied results. T T METHODS:As part of a randomized controlled trial, 65 patients were randomized into a physiotherapy treatment group for hip OA, in which they completed 4 physical performance measures at baseline and 9 weeks. Upon completion of physiotherapy, patients assessed their response to treatment on a 15-point global rating of change scale (GRCS). MCII was estimated using 3 variations of an anchor-based method, based on the patient's opinion. T T RESULTS:A comparison of 3 methods resulted in the following change scores being best associated with our definition of MCII: a reduction equal to or greater than 0.8, 1.4, and 1.2 seconds for the TUG; an increase equal to or greater than 0.2, 0.3, and 0.2 m/s for the 40-m SPWT; an increase equal to or greater than 2.0, 2.6, and 2.1 repetitions for the 30 CST; an increase equal to or greater than 5.0, 12.8, and 16.4 steps for the 20-cm step test. T T CONCLUSION:The variation in methods provided very different results. This illustrates the impor...

The test/retest reliability of physical performance measures in osteoarthritis patients

“…Although there is extensive data validating subjective measures of OA of the knee there is currently only limited data examining objective measures which are likely to be of equal importance when assessing clinical intervention for OA [10,11]. Previously published data support the reliability of the 40 m walk in assessing patients with hip OA [12] and the data presented herein support its application to patients with knee OA. Additionally a 20 m walk as well as an 11 step stair climb appears highly reliable and reproducible assessments when examining knee OA.…”

Changes in Balance after Rehabilitation Program in Patients with COPD and in Healthy Subjects

“…This significant improvement is superior to the minimum clinically important difference (MCID) for the TUG evaluated by Wright et al [42] by three different methods for patients with hip osteoarthritis: the MCID is estimated between 0.8 and 1.4 seconds. To our knowledge, no study has described the MCID in patients with COPD.…”

Measurement properties of performance-based measures to assess physical function in hip and knee osteoarthritis: a systematic review

“…Three studies included participants with hip OA 24,30,32 , five with knee OA 6,20,22,26,27 and 16 with both hip and knee OA 7,8,10,21,23,25,28,29,31,33e39 . The majority of studies included participants in the end stage of OA or the stage of disease was not specified.…”