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Quality of Life Research

, Volume 25, Issue 2, pp 267–274 | Cite as

The case for using country-specific scoring coefficients for scoring the SF-12, with scoring implications for the SF-36

  • Graeme TuckerEmail author
  • Robert Adams
  • David Wilson
Article

Abstract

Purpose

To examine the validity of using the same scoring coefficients across countries for the SF-12.

Methods

We test the equality of scoring coefficients derived for a contraction of the SF-36, the Short Form 12 (SF-12), using a large international database drawn from nine countries, to test equality between Australia and twelve other country/language groups. First, we checked that the theoretical structure of the SF-12 as set out by Ware and colleagues, but including a correlation between physical and mental health, provided an adequate fit to the data for each country/language group in a confirmatory factor analysis. We then compared Australia to all of these country/language groups in multiple-group models to assess whether a model producing common factor score coefficients provided an adequate fit to the data. We also derived Chi-squared tests for the differences between the restricted and unrestricted models, to test the equality of the factor score coefficients across countries.

Results

We found that the theoretical structure of the SF-12, with a correlation between physical and mental health, provides an adequate fit to the data for all country/language groups except Hungary. Further, all the unrestricted multiple-group models provide an adequate fit to the data. In contrast, none of the multiple-group models restricted to common parameters provide an adequate fit to the data. The significance tests confirm that the constraints on parameter values produce significantly different models to the unrestricted models.

Conclusions

We conclude that researchers should derive their own country-specific scoring coefficients for physical and mental health summary scores.

Keywords

Self-rated health Health-related quality of Life SF-36 SF-12 International comparisons 

Notes

Compliance with ethical standards

Competing interests and funding

This work was unfunded. The authors are unaware of any possible conflict of interest in the production of this publication.

Ethical standard

This paper is based on a secondary analysis of various International and Australian survey files. As such, this analysis did not require formal ethics approval; however, all of the original data collections were conducted under ethics approval with the informed consent of the participants.

Supplementary material

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Supplementary material 1 (PDF 198 kb)
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Supplementary material 2 (PDF 525 kb)
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Supplementary material 3 (PDF 279 kb)
11136_2015_1083_MOESM4_ESM.pdf (114 kb)
Supplementary material 4 (PDF 114 kb)

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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.SA HealthAdelaideAustralia
  2. 2.The Health Observatory, Discipline of Medicine, The Queen Elizabeth Hospital CampusUniversity of AdelaideAdelaideAustralia
  3. 3.Discipline of MedicineUniversity of AdelaideAdelaideAustralia

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