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Quality of Life Research

, Volume 22, Issue 4, pp 695–703 | Cite as

Relative importance measures for reprioritization response shift

  • Lisa M. Lix
  • Tolulope T. Sajobi
  • Richard Sawatzky
  • Juxin Liu
  • Nancy E. Mayo
  • Yuhui Huang
  • Lesley A. Graff
  • John R. Walker
  • Jason Ediger
  • Ian Clara
  • Kathryn Sexton
  • Rachel Carr
  • Charles N. Bernstein
Article

Abstract

Purpose

Response shift (RS), a change in the meaning of an individual’s self-evaluation of a target construct, such as health-related quality of life (HRQOL), can affect the interpretation of change in measures of the construct collected over time. This study proposes new statistical methods to test for reprioritization RS, in which the relative importance of HRQOL domains changes over time.

Methods

The methods use descriptive discriminant analysis or logistic regression models and bootstrap inference to test for change in relative importance weights (Method 1) or ranks (Method 2) for discriminating between patient groups at two occasions. The methods are demonstrated using data from the Manitoba Inflammatory Bowel Disease (IBD) Cohort Study (n = 388). Reprioritization of domains from the IBD Questionnaire (IBDQ) and SF-36 was investigated for groups with active and inactive disease symptoms.

Results

The IBDQ bowel symptoms and SF-36 bodily pain domains had the highest ranks for group discrimination. Using Method 1, there was evidence of reprioritization RS in the IBDQ social functioning domain and the SF-36 bodily pain and social functioning domains. Method 2 did not detect change for any of the domains.

Conclusions

Compared to IBD patients without active disease symptoms, those with active symptoms were likely to change the meaning of their self-evaluations of pain and social interactions. Further research is needed to compare these new RS detection methods under a variety of data analytic conditions before recommendations about the optimal method can be made.

Keywords

Discriminant analysis Inflammatory bowel disease Logistic regression Longitudinal Relative importance Response shift 

Abbreviations

DDA

Descriptive discriminant analysis

DRC

Discriminant ratio coefficient

HRQOL

Health-related quality of life

IBD

Inflammatory bowel disease

IBDQ

Inflammatory Bowel Disease Questionnaire

LR

Logistic regression

LPI

Logistic Pratt’s index

RS

Response shift

SDFC

Standardized discriminant function coefficient

SEM

Structural equation modeling

SF-36

36-item Short-Form Questionnaire

SLRC

Standardized logistic regression coefficient

Notes

Acknowledgments

This research was supported by a Canadian Institutes of Health Research (CIHR) New Investigator award and University of Saskatchewan Centennial Chair to the first author, a CIHR Vanier Graduate Scholarship to the second author, and a CIHR Operating Grant to the research team.

Supplementary material

11136_2012_198_MOESM1_ESM.doc (64 kb)
Supplementary material 1 (DOC 63 kb)

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Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Lisa M. Lix
    • 1
  • Tolulope T. Sajobi
    • 1
  • Richard Sawatzky
    • 2
  • Juxin Liu
    • 6
  • Nancy E. Mayo
    • 3
  • Yuhui Huang
    • 4
  • Lesley A. Graff
    • 5
  • John R. Walker
    • 5
  • Jason Ediger
    • 5
  • Ian Clara
    • 5
  • Kathryn Sexton
    • 5
  • Rachel Carr
    • 5
  • Charles N. Bernstein
    • 5
  1. 1.School of Public HealthUniversity of SaskatchewanSaskatoonCanada
  2. 2.Trinity Western UniversityLangleyCanada
  3. 3.McGill University Health CentreMontrealCanada
  4. 4.University of ReginaReginaCanada
  5. 5.University of ManitobaWinnipegCanada
  6. 6.University of SaskatchewanSaskatoonCanada

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