A comparison of 3 methodological approaches to defining major clinically important improvement of 4 performance measures in patients with hip osteoarthritis

J Orthop Sports Phys Ther. 2011 May;41(5):319-27. doi: 10.2519/jospt.2011.3515. Epub 2011 Feb 18.


Study design: Prospective cohort study.

Objectives: To establish the major clinically important improvement (MCII) of the timed up-and-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.

Background: Minimal clinically important difference 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.

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.

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.

Conclusion: The variation in methods provided very different results. This illustrates the importance of comparing methodologies and reporting a range of values associated with the MCII, as such values vary, depending upon the methodology chosen.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Exercise Test
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Motor Activity / physiology*
  • Osteoarthritis, Hip / physiopathology*
  • Osteoarthritis, Hip / rehabilitation*
  • Outcome Assessment, Health Care*
  • Physical Therapy Modalities*
  • Recovery of Function / physiology*
  • Reproducibility of Results