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Two Kinds of Items in Quality of Life Instruments: ‘Indicator and Causal Variables’ in the EORTC QLQ-C30

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Abstract

Two kinds of variables may be differentiated within instruments measuring health-related quality of life (HRQOL). Physical symptoms may be called causal variables because their occurrence can cause a change in HRQOL, but poor HRQOL need not necessarily imply that a patient suffers from these symptoms. Other items can be regarded as indicator variables. They reflect the level of HRQOL and a patient with a poor HRQOL is likely to have low scores on all indicator variables. The aim of this study was to test the relationship of the latent HRQOL construct to items and domains on the EORTC QLQ-C30. Confirmatory factor analysis was performed on EORTC QLQ-C30 data from 205 gastrointestinal cancer patients assessed one month after surgery. Functioning scales were established as variables indicating the level of HRQOL whereas all other subscales and items were established as variables causing a change in HRQOL. The model-data fit was satisfactory. Results support the hypothesis that two kinds of variables may be differentiated within HRQOL instruments. Further research should investigate whether both kinds of variables could be combined into a higher order, aggregate score for HRQOL.

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Abbreviations

CFA:

Confirmatory factor analysis

CFI:

Comparative Fit Index

EORTC QLQ-C30:

European Organization for Research and Treatment of Cancer Quality of Life Questionnaire – Core

HRQOL:

Health-related quality of life

MIMIC:

Multiple indicator multiple cause

RMSEA:

Root-mean-square error of approximation

SMC:

Squared multiple correlation

TLI:

Tucker Lewis Index

References

  1. H McGee (2004) Quality of life A Kaptein J Weinman (Eds) Health Psychology The British Psychological Society and Blackwell Publishing Ltd Oxford 234–257

    Google Scholar 

  2. CA. McHorney (1999 ) ArticleTitleHealth status assessment methods for adults: past accomplishments and future challenges Annu Rev Public Health 20 309–335 Occurrence Handle10.1146/annurev.publhealth.20.1.309 Occurrence Handle1:STN:280:DyaK1M3otFWhtQ%3D%3D Occurrence Handle10352861

    Article  CAS  PubMed  Google Scholar 

  3. CC Gotay D Blaine SN Haynes J Holup IS Pagano (2002) ArticleTitleAssessment of quality of life in a multicultural cancer patient population Psychol Assess 14 439–448 Occurrence Handle12501569

    PubMed  Google Scholar 

  4. BJ Zebrack MA Chesler (2001) ArticleTitleA psychometric analysis of the Quality of Life Cancer Survivors (QIO-CS) in survivors of childhood cancer Qual Life Res 10 319–329 Occurrence Handle10.1023/A:1012228823115 Occurrence Handle1:STN:280:DC%2BD38%2FjsVymtw%3D%3D Occurrence Handle11763245

    Article  CAS  PubMed  Google Scholar 

  5. PM Fayers DJ Hand (1997) ArticleTitleFactor analysis, causal indicators and quality of life Qual Life Res 6 139–150 Occurrence Handle1:STN:280:DyaK2szgsVyisg%3D%3D Occurrence Handle9161114

    CAS  PubMed  Google Scholar 

  6. PM Fayers DJ Hand (2002) ArticleTitleCausal variables, indicator variables and measurement scales: an example from quality of life J R Statist Soc A 165 233–261 Occurrence Handle10.1111/1467-985X.02020

    Article  Google Scholar 

  7. PM Fayers DJ Hand K Bjordal M Groenvold (1997) ArticleTitleCausal indicators in quality of life research Qual Life Res 6 393–406 Occurrence Handle1:STN:280:DyaK2svjsFKgsw%3D%3D Occurrence Handle9290306

    CAS  PubMed  Google Scholar 

  8. D Borsboom GD Mellenberg J Heerden Particlevan (2003) ArticleTitleThe theoretical status of latent variables Psychol Rev 110 203–219 Occurrence Handle12747522

    PubMed  Google Scholar 

  9. KA Bollen (1989) Structural Equations with Latent Variables Wiley & Sons New York

    Google Scholar 

  10. PM Fayers M Groenvold DJ Hand K Bjordal (1998) ArticleTitleClinical impact versus factor analysis for quality of life questionnaire construction J Clin Epidemiol 51 285–286 Occurrence Handle1:STN:280:DyaK1c7lsFSrsA%3D%3D Occurrence Handle9495694

    CAS  PubMed  Google Scholar 

  11. NK Aaronson S Ahmedzai B Bergman et al. (1993) ArticleTitleThe European Organization for Research and Treatment of Cancer QLQ-C30: A quality-of-life instrument for use in international clinical trials in oncology J Natl Cancer Inst 85 365–376 Occurrence Handle1:STN:280:DyaK3s7msVarsQ%3D%3D Occurrence Handle8433390

    CAS  PubMed  Google Scholar 

  12. PM Fayers NK Aaronson K Bjordal M Groenvold D Curran A Bottomley (2001) On behalf of the EORTC Quality of Life Group. The EORTC QLQ-C30 Scoring Manual (3rd Edition) European Organisation for Research and Treatment of Cancer Brussels

    Google Scholar 

  13. InstitutionalAuthorNameWHO (1948) World Health Organization Constitution WHO Geneva, Switzerland

    Google Scholar 

  14. JL Arbuckle W Wothke (1999) Amos 4.0 User Guide SmallWaters Chicago, IL

    Google Scholar 

  15. SY Lee WY Poon PM Bentler (1992) ArticleTitleStructural equation models with continuous and polytomous variables Psychometrika 57 89–105

    Google Scholar 

  16. SY Lee WY Poon PM Bentler (1990) ArticleTitleFull maximum likelihood analysis of structural equation models with polytomous variables Stat Probabil Lett 9 91–97

    Google Scholar 

  17. SY Lee JQ Shi (2001) ArticleTitleMaximum likelihood estimation of two-level latent variable models with mixed continuous and polytomous data Biometrics 57 787–794 Occurrence Handle1:STN:280:DC%2BD3MrgtFOhtw%3D%3D Occurrence Handle11550929

    CAS  PubMed  Google Scholar 

  18. BO Muthen D Kaplan (1985) ArticleTitleA comparison of some methodologies for the factor analysis of non-normal likert variables Br J Math Stat Psychol 45 19–30

    Google Scholar 

  19. L Hu PM Bentler Y Kano (1988) ArticleTitleCan test statistics in covariance structure analysis be trusted? Psychol Bull 112 351–362

    Google Scholar 

  20. KG Joreskog D. Sorbom (1993) Lisrel8. Sturctural Equation Modeling with SIMPLIS Command Language Erlbaum Hillsdale, NJ

    Google Scholar 

  21. CP Chou P Bentler (1995) Estimates and tests in structural equation modeling R Hoyle (Eds) Structural Equation Modeling: Concepts, Issues, and Applications Sage Publications Thousand Oaks, CA 37–55

    Google Scholar 

  22. Tomarken AJ, Waller NG. Structural equation modeling: Strengths, limitations, and misconceptions. Annu Rev Clin Psychol November 11 2004; 1: 2.1–2.35; 10.1146/annurev.clinpsy.1.102803.144239

  23. J Nevitt GR Hancock (2001) ArticleTitlePerformance of bootstrapping approaches to model test statistics and parameter standard error estimation in structural equation modeling Struct Equ Model 8 353–377 Occurrence Handle10.1207/S15328007SEM0803_2

    Article  Google Scholar 

  24. GR Hancock J Nevitt (1999) ArticleTitleBootstrapping and the identification of exogenous latent variables within structural equation models Struct Equ Model 6 394–399

    Google Scholar 

  25. BG Tabachnick LS Fidell (2001) Using Multivariate Statistics Allyn & Bacon Needham Heights, MA 653–771

    Google Scholar 

  26. MW Browne R Cudeck (1993) Alternative ways of assessing model fit KA Bollen JS Long (Eds) Testing Structural Equation Models Sage Newbury Park, CA 136–162

    Google Scholar 

  27. KG Jöreskog D Sörbom (1996) LISREL 8 User’s Reference Guide Sci. Software Int. Chicago

    Google Scholar 

  28. LK Muthén BO Muthén (1998) Mplus User’s Guide Muthén & Muthén Los Angeles, CA

    Google Scholar 

  29. LK Muthén BO Muthén (2002) Mplus version 2.12: Addendum to the Mplus User’s Guide Muthén, Muthén Los Angeles, CA

    Google Scholar 

  30. DR Cox R Fitzpatrick AE Fletcher SM Gore DJ Spiegelhalter DR Jones (1992) ArticleTitleQuality-of-life assessment: can we keep it simple? J R Statist Soc A 155 353–393

    Google Scholar 

  31. L Prieto J Alonso MC Vildarich (1996) ArticleTitleScaling the Spanish version of the Nottingham Health Profile: Evidence of limited value of item weights J Clin Epidem Anto JM 49 31–38 Occurrence Handle1:STN:280:DyaK287ntlCrtQ%3D%3D

    CAS  Google Scholar 

  32. GW Torrance DH Feeny WJ Furlong RD Barr Y Zhang Q Wang (1996) ArticleTitleMultiattribute utility function for a comprehensive health status classification system: Health Utilities Index Mark 2 Med Care 34 702–722 Occurrence Handle10.1097/00005650-199607000-00004 Occurrence Handle1:STN:280:DyaK28zhsFCltg%3D%3D Occurrence Handle8676608

    Article  CAS  PubMed  Google Scholar 

  33. JP Browne CA O’Boyle H McGee NJ McDonald CRB Joyce (1997) ArticleTitleDevelopment of a direct weighting procedure for quality of life domains Qual Life Res 6 301–309 Occurrence Handle10.1023/A:1018423124390 Occurrence Handle1:STN:280:DyaK2szptFGhsg%3D%3D Occurrence Handle9248312

    Article  CAS  PubMed  Google Scholar 

  34. M Ryan S Farrar (2000) ArticleTitleUsing conjoint analysis to elicit preferences for health care Br Med J 320 1530–1533 Occurrence Handle1:STN:280:DC%2BD3c3psV2msA%3D%3D

    CAS  Google Scholar 

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Authors and Affiliations

  1. Department of Health Psychology, Free Universität of Berlin, Habelschwerdter Allee 45, 14195, Berlin, Germany

    Sonja Boehmer

  2. School of Life Sciences, University of Sussex, UK, and Warsaw School of Social Psychology, Poland

    Aleksandra Luszczynska

Authors
  1. Sonja Boehmer
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  2. Aleksandra Luszczynska
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Correspondence to Sonja Boehmer.

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Boehmer, S., Luszczynska, A. Two Kinds of Items in Quality of Life Instruments: ‘Indicator and Causal Variables’ in the EORTC QLQ-C30. Qual Life Res 15, 131–141 (2006). https://doi.org/10.1007/s11136-005-8290-6

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  • DOI: https://doi.org/10.1007/s11136-005-8290-6

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