Skip to main content

The Assessment of Quality of Life (AQoL) instrument: a psychometric measure of Health-Related Quality of Life

Abstract

This paper describes constructing the Assessment of Quality of Life (AQoL) instrument; designed to measure health-related quality of life (HRQoL), and to be the descriptive system for a multi-attribute utility instrument. Unlike previous utility instruments' descriptive systems, the AQoL's has been developed using state-of-the-art psychometric procedures. The result is a descriptive system which emphasizes five different facets of HRQoL and which can claim to have construct validity. Based on the WHO's definition of health a model of HRQoL was developed. Items were written by focus groups of doctors and the researchers. These were administered to a construction sample, comprising hospital patients, and community members chosen at random. Final construction was through an iterative process of factor and reliability analyses. The AQoL measures 5 dimensions: illness, independent living, social relationships, physical senses and psychological wellbeing. Each has three items. Exploratory factor analysis showed the dimensions were orthogonal, and each was unidimensional. Internal consistency was α = 0.81. Structural equation modeling explored its internal structure; the comparative fit index was 0.90. These preliminary results indicate the AQoL has the prerequisite qualities for a psychometric HRQoL instrument for evaluation; replication with a larger sample is needed to verify these findings. Scaling it for economic evaluation using utilities is being undertaken. Respondents have indicated the AQoL is easy to understand and is quickly completed. Its initial properties suggest it may be widely applicable.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    Nordenfelt L (ed). Concepts and Measurement of Quality of Life in Health Care. Dordrecht: Kluwer Academic Publishers, 1994.

    Google Scholar 

  2. 2.

    Torrance G. Measurement of health state utilities for economic appraisal: a review. Journal of Health Eco-nomics. 1986; 5: 1±30.

    Google Scholar 

  3. 3.

    Murray C, Lopez A. The Global Burden of Disease. Geneva: World Health Organization, 1996.

    Google Scholar 

  4. 4.

    Cronbach J, Meehl P. Construct validity in psycho-logical tests. Psychological Bulletin. 1955; 52(4): 281±302.

    Google Scholar 

  5. 5.

    Rosser R. A health index and output measure. In: Walker S, Rosser R (Eds). Quality of Life Assessment: Key Issues in the 1990s. Dordrecht: Kluwer Academic Publishers, 1993.

    Google Scholar 

  6. 6.

    Kind P, Rosser R. The quali®cation of health. European Journal of Social Psychology. 1988; 18: 63±77.

    Google Scholar 

  7. 7.

    Kaplan R, Bush J, Berry C. Health status: types of validity and the Index of Well-being. Health Services Research. 1976; 11(4): 478±507.

    Google Scholar 

  8. 8.

    Kaplan R, Bush J. Health-related quality of life mea-surement for evaluation research and policy analysis. Health Psychology. 1982; 1: 61±80.

    Google Scholar 

  9. 9.

    Kaplan R, Anderson J, Ganiats T. The Quality of Well-Being Scale: rationale for a single quality of life index. In: Walker S, Rosser R (Eds). Quality of Life Assess-ment: Key Issues in the 1990s. Dordrecht: Kluwer Ac-ademic Publishers, 1993.

    Google Scholar 

  10. 10.

    Torrance G, Zhang Y, Feeny D, Furlong W, Barr R. Multi-attribute preference functions for a comprehen-sive health status classi®cation system. Working Paper 92±18. Hamilton, Ontario: CHEPA, 1992.

    Google Scholar 

  11. 11.

    Boyle M, Furlong W, Feeny D, Torrance G, Hatcher J. Reliability of the Health Utilities Index-mark III used in the 1991 cycle 6 Canadian general social survey health questionnaire. Quality of Life Research. 1995; 4: 249±257.

    Google Scholar 

  12. 12.

    Torrance G, Furlong W, Feeny D, Boyle M. Multi-attribute preference functions: health utilities index. PharmacoEconomics. 1995; 7(6): 503±520.

    Google Scholar 

  13. 13.

    Feeny D, Torrance G, Furlong W. Health utilities in-dex. In: Spilker B (ed). Quality of Life and Pharmaco-economics in clinical trials, 2nd ed. Philadelphia: Lippincott-Raven Publishers, 1996.

    Google Scholar 

  14. 14.

    Sintonen H. An approach to measuring and valuing health states. Social Science and Medicine. 1981; 15: 55±65.

    Google Scholar 

  15. 15.

    Sintonen H, Pekurinen M. A ®fteen-dimensional mea-sure of health-related quality of life (15D) and its ap-plications. In: Walker S, Rosser R (Eds). Quality of Life Assessment. Dordrecht: Kluwer Academic Publishers, 1993.

    Google Scholar 

  16. 16.

    Sintonen H. The 15D measure of health-related quality of life: reliability, validity and sensitivity of its health state descriptive system. Working Paper 41. Mel-bourne: National Centre for Health Program Evalua-tion, 1994.

    Google Scholar 

  17. 17.

    Sintonen H. The 15D measure of health-related quality of life: feasibility, reliability and validity of its valuation system. Working Paper 42. Melbourne: National Centre for Health Program Evaluation, 1995.

    Google Scholar 

  18. 18.

    EuroQoLGroup. EuroQoL ± a new facility for the measurement of health-related quality of life. Health Policy. 1990; 16: 199±208.

    Google Scholar 

  19. 19.

    Gudex C. EuroQoL state valuations from the general population: the visual analogue method. Health Econ-omists Study Group. Newcastle, 6±8July, 1994.

  20. 20.

    Van Agt H, Essink-Bot M-L, Krabbe P, Bonsel G. Test-retest reliability of health state valuations collected with the EuroQol questionnaire. Social Science and Medicine. 1994; 39(11): 1537±1544.

    Google Scholar 

  21. 21.

    Williams A. The Measurement and Valuation of Health: A Chronicle. Discussion Paper 136. York: Centre for Health Economics, 1995.

    Google Scholar 

  22. 22.

    Drummond M, Stoddart G, Torrance G. Methods for the Economic Evaluation of Health Care Programmes. Oxford: Oxford University Press, 1987.

    Google Scholar 

  23. 23.

    Nord E, Richardson J, Macarounas-Kirchmann K. Social evaluation of health care versus personal evalu-ation of health states. Evidence on the validity of four health-state scaling instruments using Norwegian and Australian surveys. Int. J. Technol. Assess. Health Care. 1993; 9(4): 463±78.

    Google Scholar 

  24. 24.

    Feeny D, Furlong W, Boyle M, G T. Multi-attribute health status classi®cation systems. PharmacoEconomics. 1995; 7(6): 489±502.

    Google Scholar 

  25. 25.

    Drummond M. Economic evaluation and the rational di.usion and use of health technology. Health Policy. 1987; 7: 309±324.

    Google Scholar 

  26. 26.

    MVHGroup. The Measurement and Valuation of Health: Final Modelling of Valuation Tari.s. York: Centre for Health Economics, 1995.

    Google Scholar 

  27. 27.

    Gescheider G. Psychophysical Scaling. Am. Rev. Psy-chol. 1988; 39: 169±200.

    Google Scholar 

  28. 28.

    Richardson J. Cost utility analysis: what should be measured? Social Science and Medicine. 1994; 39(1): 7±21.

    Google Scholar 

  29. 29.

    Fava J, Velicer W, Rossi J. Procedures for developing quality measures. Fourth International Conference of Behaviour Medicine. Washington, 1996.

  30. 30.

    Juniper E, Guyatt G, Jaeschke R. How to develop and validate a new health-related quality of life instrument. In: Spilker B (ed). Quality of Life and Pharmacoeco-nomics, 2nd ed. Philadelphia: Lippincott-Raven Pub-lishers, 1996.

    Google Scholar 

  31. 31.

    Theobald J. Writing the test item. Classroom Testing: Principles and Practice. Melbourne: Longman Hall, 1974.

    Google Scholar 

  32. 32.

    Foddy W. Constructing Questions for Interviews and Questionnaires: Theory and Practice in Social Research. Cambridge: Cambridge University Press, 1993.

    Google Scholar 

  33. 33.

    Guadagnoli E, Velicer W. Relation of sample size to the stability of component patterns. Psychological Bulletin. 1988; 103(2): 265±275.

    Google Scholar 

  34. 34.

    WHO. The First Ten Years of the World Health Or-ganization. Geneva: World Health Organization, 1958.

    Google Scholar 

  35. 35.

    Guyatt G, Feeny D, Patrick D. Measuring health-re-lated quality of life. Annals of Internal Medicine. 1993; 118: 622±629.

    Google Scholar 

  36. 36.

    WHO. International Classi®cation of Impairments, Disabilities and Handicaps. Geneva: World Health Organization, 1980.

    Google Scholar 

  37. 37.

    Bergner M, Bobbit R, Carter W, Gilson B. The Sickness Impact Pro®le; development and revision of a health status measure. Medical Care. 1981; 19: 787±805.

    Google Scholar 

  38. 38.

    Bergner M. Development, testing and use of the Sick-ness Impact Pro®le. In: Walker S, Rosser R (Eds). Quality of Life Assessment: Key Issues in the 1990s. Dordrecht: Kluwer Academic Publishers, 1993.

    Google Scholar 

  39. 39.

    Kaplan R, Ganiats T, Sieber W, Anderson J. The Quality of Well-being Scale. Medical Outcomes Trust Bulletin. 1996: 2±3.

  40. 40.

    Dolan P, Gudex C, Kind P, Williams A. Social Tari. for EUROQoL: Results from a UK General Population Survey. Discussion Paper 138. York: Centre for Health Economics, University of York, 1995.

    Google Scholar 

  41. 41.

    Goldberg D. The General Health Questionnaire. In: McDowell I, Newell C, eds, Measuring Health: A Guide to Rating Scales and Questionnaires. New York: Oxford University Press, 1972.

    Google Scholar 

  42. 42.

    Gurel L. Mental and physical impairment-of-function evaluation in the aged: the PAMIE scale. J. Gerontol. 1972; 27: 83±90.

    Google Scholar 

  43. 43.

    Hunt S, McKenna S, McEwen J. The Nottingham health pro®le user's manual. Manchester: Galen Re-search & Consultancies, 1989.

    Google Scholar 

  44. 44.

    Jette A. Functional status index: reliability of a chronic disease evaluation instrument. Arch. Phys. Med. Re-habil. 1980; 61: 395±401.

    Google Scholar 

  45. 45.

    Chambers L. The McMaster Health Index Question-naire. Hamilton: McMaster University, 1982.

    Google Scholar 

  46. 46.

    Meenan R, Gertman P, Mason J. Measuring health status in arthritis: the Arthritis Impact Measurement Scales. Arthritis Rheum. 1980; 23: 146±152.

    Google Scholar 

  47. 47.

    Fillenbaum G, Smyer M. The development, validity and reliability of the OARS Multidimensional Func-tional Assessment Questionnaire. J. Gerontol. 1981; 36: 428±434.

    Google Scholar 

  48. 48.

    Rosser R, Kind P. A scale of valuations of states of illness: is there a social consensus. International Journal of Epidemiology. 1978; 7: 4±15.

    Google Scholar 

  49. 49.

    Ware J, Snow K, Kosinski M, Gandek B. SF-36 health survey: manual and interpretation guide. Bos-ton: The Health Institute, New England Medical Centre, 1993.

    Google Scholar 

  50. 50.

    McDowell I, Newell C (Eds). Measuring health: a guide to rating scales and questionnaires. New York: Oxford University Press, 1987.

    Google Scholar 

  51. 51.

    Walker S, Rosser R. Quality of life assessment: key is-sues in the 1990s. Dordrecht: Kluwer Academic Pub-lishers, 1993.

    Google Scholar 

  52. 52.

    Bowling A. Measuring Health: A Review of Quality of Life Measurement Scales. Milton Keynes: Open Uni-versity, 1991.

    Google Scholar 

  53. 53.

    WHO. Measuring Quality of Life. Geneva: World Health Organization; Division of Mental Health, 1993.

    Google Scholar 

  54. 54.

    Winterfeldt DV, Edwards W. Decision analysis and behavioural research. Cambridge: Cambridge Univer-sity Press, 1986.

    Google Scholar 

  55. 55.

    Rummel R. Applied factor analysis. Evanston: 1970.

  56. 56.

    Anastasi A. Psychological Testing, 4th ed. New York: Macmillan Publishing, 1976.

    Google Scholar 

  57. 57.

    Hawthorne G, McNeil H, Osborne R, Richardson J. Endpoints: Issues in the Meaning of 'Good Health' in Health-Related Quality of Life Measurement. Melbourne: Centre for Health Program Evaluation, 1998.

    Google Scholar 

  58. 58.

    Cummins R. The comprehensive quality of life scale: theory and development. In: Sansoni J (ed). Proceed-ings Health Outcomes and Quality of Life Measure-ment Conference. Canberra: Australian Institute of Health and Welfare, 1995: 18±24.

    Google Scholar 

  59. 59.

    McArdle J. Current directions in structural factor analysis. Current Directions in Psychological Science. 1996; 5(1): 11±18.

    Google Scholar 

  60. 60.

    Pedhazur E, Schmelkin L. Measurement, Design and Analysis: An Integrated Approach. Hillsdale: Lawrence Erlbaum, 1991.

    Google Scholar 

  61. 61.

    Bagozzi R, Heatherton T. A general approach to rep-resenting multifaceted personality constructs: applica-tion to state self-esteem. Structural Equation Modelling. 1994; 1(1): 35±67.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hawthorne, G., Richardson, J. & Osborne, R. The Assessment of Quality of Life (AQoL) instrument: a psychometric measure of Health-Related Quality of Life. Qual Life Res 8, 209–224 (1999). https://doi.org/10.1023/A:1008815005736

Download citation

  • Economic value of life
  • Evaluation studies
  • Health status indicators
  • Psychometrics
  • Quality of life