Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Sep;22(9):2163-71.
doi: 10.1007/s00167-013-2654-1. Epub 2013 Sep 6.

Influence of response shift on early patient-reported outcomes following autologous chondrocyte implantation

Jennifer S Howard  1 , Carl G Mattacola, David R Mullineaux, Robert A English, Christian Lattermann
Affiliations

Influence of response shift on early patient-reported outcomes following autologous chondrocyte implantation

Jennifer S Howard et al. Knee Surg Sports Traumatol Arthrosc. 2014 Sep.

Erratum in

  • Knee Surg Sports Traumatol Arthrosc. 2014 Sep;22(9):2172

Abstract

Purpose: Response shift is the phenomenon by which an individual's standards for evaluation change over time. The purpose of this study was to determine whether patients undergoing autologous chondrocyte implantation (ACI) experience response shift.

Methods: Forty-eight patients undergoing ACI participated. The "then-test" method was used to evaluate response shift in commonly used patient-reported outcome measures (PROMs)-the SF-36 Physical Component Scale (SF-36 PCS), WOMAC, IKDC, and Lysholm. Each PROM was completed pre- and 6 and 12 months post-surgery. At 6 and 12 months, an additional "then" version of each form was also completed. The "then" version was identical to the original except that patients were instructed to assess how they were prior to ACI. Traditional change, response shift adjusted change, and response shift magnitude were calculated at 6 and 12 months. T tests (p < 0.05) were used to compare traditional change to response-shift-adjusted change, and response shift magnitude values to previously established minimal detectable change.

Results: There were no differences between traditional change and response-shift-adjusted change for any of the PROMs. The mean response shift magnitude value of the WOMAC at 6 months (15 ± 14, p = 0.047) was greater than the previously established minimal detectable change (10.9). The mean response shift magnitude value for the SF-36 PCS at 12 months (9.4 ± 6.8, p = 0.017) also exceeded the previously established minimal detectable change (6.6).

Conclusions: There was no evidence of a group-level effect for response shift. These results support the validity of pre-test/post-test research designs in evaluating treatment effects. However, there is evidence that response shifts may occur on a patient-by-patient basis, and scores on the WOMAC and SF-36 in particular may be influenced by response shift.

Level of evidence: II.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Study enrolment and follow-up
Fig. 2
Fig. 2
Then-test method for assessing response shift. For the then-test method, patients are requested to complete an outcome instrument three times. First pre-treatment (pre-test), again at a specified post-treatment time point (post-test), and at that same post-treatment time point, they also complete a then-test on which they are asked to retrospectively rate how they were at the pre-treatment time point. From these three scores, response shift, response shift magnitude, traditional change, and response-shift-adjusted change can then be calculated. In the present study, post and then evaluations were completed at 6 and 12 months postoperatively
See this image and copyright information in PMC

References

    1. Balain B, Ennis O, Kanes G, Singhal R, Roberts SN, Rees D, Kuiper JH. Response shift in self-reported functional scores after knee microfracture for full thickness cartilage lesions. Osteoarthr Cartil. 2009;17(8):1009–1013. - PubMed
    1. Beaton DE. Understanding the relevance of measured change through studies of responsiveness. Spine. 2000;25(24):3192–3199. - PubMed
    1. Bellamy N, Buchanan WW, Goldsmith CH, Campbell J, Stitt LW. Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. J Rheumatol. 1988;15(12):1833–1840. - PubMed
    1. Bentley G, Biant LC, Carrington RWJ, Akmal M, Goldberg A, Williams AM, Skinner JA, Pringle J. A prospective, randomised comparison of autologous chondrocyte implantation versus mosaicplasty for osteochondral defects in the knee. J Bone Joint Surg Br. 2003;85(2):223–230. - PubMed
    1. Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L. Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Engl J Med. 1994;331(14):889–895. - PubMed

Publication types

LinkOut - more resources