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Rasch analysis of the International Wellbeing Index in older adults

Published online by Cambridge University Press:  16 August 2011

Maria João Forjaz*
Affiliation:
National School of Public Health, Carlos III Institute of Health, Madrid, Spain CIBERNED, Carlos III Institute of Health, Madrid, Spain
Alba Ayala
Affiliation:
National School of Public Health, Carlos III Institute of Health, Madrid, Spain
Carmen Rodriguez-Blazquez
Affiliation:
CIBERNED, Carlos III Institute of Health, Madrid, Spain National Centre of Epidemiology, Carlos III Institute of Health, Madrid, Spain
Maria-Eugenia Prieto-Flores
Affiliation:
National School of Public Health, Carlos III Institute of Health, Madrid, Spain
Gloria Fernandez-Mayoralas
Affiliation:
Center for Human and Social Sciences, Spanish National Research Council, Madrid, Spain
Fermina Rojo-Perez
Affiliation:
Center for Human and Social Sciences, Spanish National Research Council, Madrid, Spain
Pablo Martinez-Martin
Affiliation:
CIBERNED, Carlos III Institute of Health, Madrid, Spain Research Unit, Alzheimer Center Reina Sofia Foundation, Carlos III Institute of Health, Madrid, Spain
*
Correspondence should be addressed to: M.J. Forjaz, National School of Public Health, Carlos III Institute of Health, c/ Monforte de Lemos 5, 28029 Madrid, Spain. Phone: +34 91 822 2062; Fax: +34 91 387 7869/2. Email: [email protected].
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Abstract

Background: The International Wellbeing Index is a measure of general quality of life formed by two scales: the Personal Wellbeing Index (PWI) and the National Wellbeing Index (NWI). This paper studies the psychometric properties of the PWI and NWI, using Rasch analysis and classic psychometric methods.

Methods: The PWI and NWI were applied to a representative sample of 1106 community-dwelling adults, aged 60 years and over, residing in Spain. Mean ± standard deviation age was 72.07 ± 7.83 years and 56.3% were women.

Results: Five PWI items (achieving in life, relationships, safety, community connectedness, and future security), and five NWI items (economic situation, state of environment, social conditions, business, and national security of the country) fitted the Rasch model. After adjusting the response scale format, satisfactory fit was obtained, with good reliability (person separation index of 0.91 for both the PSI and NWI), local independency of items, and strict unidimensionality. The measures showed adequate external construct validity with related measures.

Conclusions: The PWI and the NWI, with fewer items and simpler response scale formats, provided valid and reliable linear measures in older adults, according to Rasch and classic psychometric analyses.

Type
Research Article
Copyright
Copyright © International Psychogeriatric Association 2011

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References

Andrich, D. (1978). A rating formulation for ordered response categories. Psychometrika, 43, 561573.CrossRefGoogle Scholar
Andrich, D., Lyne, A., Sheridon, B. and Luo, G. (2003). RUMM2020. Perth: RUMM Laboratory.Google Scholar
Broadhead, W. E., Gehlbach, S. H., de Gruy, F. V. and Kaplan, B. H. (1988). The Duke-UNC Functional Social Support Questionnaire: measurement of social support in family medicine patients. Medical Care, 26, 709723.CrossRefGoogle ScholarPubMed
Casas, F., Figuer, C., Gonzalez, M. and Malo, S. (2007). The values adolescents aspire to, their well-being and the values parents aspire to for their children. Social Indicators Research, 84, 271290. doi: 10.1007/s11205-007-9141-3.CrossRefGoogle Scholar
Cummins, R. A., Eckersley, R., Pallant, J., Van Vugt, J. and Misajon, R. (2003). Developing a national index of subjective wellbeing: the Australian Unity Wellbeing Index. Social Indicators Research, 64, 159190.CrossRefGoogle Scholar
Davey, G., Chen, Z. and Lau, A. (2009). Peace in a thatched hut – that is happiness: subjective wellbeing among peasants in rural China. Journal of Happiness Studies, 10, 239252. doi 10.1007/s10902–007-9078-x.CrossRefGoogle Scholar
De Jong Gierveld, J. and van Tilburg, T. (2006). A 6-item scale for overall, emotional, and social loneliness confirmatory tests on survey data. Research on Aging, 28, 582598. doi: 10.1177/0164027506289723.CrossRefGoogle Scholar
EuroQol Group (1990). EuroQol: a new facility for the measurement of health-related quality of life. The EuroQol Group. Health Policy, 16, 199208.CrossRefGoogle Scholar
Fisher, W. Jr. (1992). Reliability statistics. Rasch Measurement Transactions, 6, 238.Google Scholar
Forjaz, M. J. et al. (2011). Measurement properties of the Community Wellbeing Index in older adults. Quality of Life Research, 20, 733743. doi: 10.1007/s11136-010-9794-2.CrossRefGoogle ScholarPubMed
International Wellbeing Group (2006). Personal Wellbeing Index. 4th edn.Melbourne: Australian Centre on Quality of Life, Deakin University.Google Scholar
Juniper, E. F., Guyatt, G. H. and Jaeschke, R. (1996). How to develop and validate a new health-related quality of life instrument. Pilker, In B. (ed.), Quality of Life and Pharmacoeconomics in Clinical Trials, 2nd edn (pp. 4956). Philadelphia: Lippincott-Raven Publisher.Google Scholar
Lau, A. L., Chi, I., Cummins, R. A., Lee, T. M., Chou, K. L. and Chung, L. W. (2008). The SARS (Severe Acute Respiratory Syndrome) pandemic in Hong Kong: effects on the subjective wellbeing of elderly and younger people. Aging and Mental Health, 12, 746760. doi: 10.1080/13607860802380607.CrossRefGoogle Scholar
Lau, A. L. D., Cummins, R. A. and McPherson, W. (2005). An investigation into the cross-cultural equivalence of the Personal Wellbeing Index. Social Indicators Research, 72, 403430.CrossRefGoogle Scholar
Linacre, J. M. (1994). Sample size and item calibration stability. Rasch Measurement Transactions, 7, 328.Google Scholar
Lundberg, O. and Peck, M. N. (1995). A simplified way of measuring sense of coherence: experiences from a population survey in Sweden. European Journal of Public Health, 5, 5659.CrossRefGoogle Scholar
Mahoney, F. I. and Barthel, D. W. (1965). Functional evaluation: the Barthel Index. Maryland State Medical Journal, 14, 6165.Google ScholarPubMed
Masters, G. N. (1982). A Rasch model for partial credit scoring. Psychometrika, 47, 149174.CrossRefGoogle Scholar
Mazaheri, M. and Theuns, P. (2009). Effects of varying response formats on self-ratings of life-satisfaction. Social Indicators Research, 90, 381395. doi: 10.1007/s11205-008-9263-2.CrossRefGoogle Scholar
Miller, M. D. et al. (1992). Rating chronic medical illness burden in geropsychiatric practice and research: application of the Cumulative Illness Rating Scale. Psychiatry Research, 41, 237248.CrossRefGoogle ScholarPubMed
Pallant, J. F. and Tennant, A. (2007). An introduction to the Rasch measurement model: an example using the Hospital Anxiety and Depression Scale (HADS). British Journal of Clinical Psychology, 46, 118. doi: 10.1348/014466506X96931CrossRefGoogle Scholar
Rasch, G. (1980). Probabilistic Models for Some Intelligence and Attainment Tests. Expanded edition. Chicago: University of Chicago Press.Google Scholar
Renn, D., Pfaffenberger, N., Platter, M., Mitmansgruber, H., Cummins, R. A. and Hofer, S. (2009). International Well-being Index: the Austrian version. Social Indicators Research, 90, 243256. doi: 10.1007/s11205-008-9255-2.CrossRefGoogle Scholar
Rodriguez-Blazquez, C. et al. (2011). Psychometric properties of the International Wellbeing Index in community-dwelling older adults. International Psychogeriatrics, 23, 161169. doi:10.1017/S104161021000092X.CrossRefGoogle ScholarPubMed
SmithE. V., Jr. E. V., Jr. (2002). Detecting and evaluating the impact of multidimensionality using item fit statistics and principal component analysis of residuals. Journal of Applied Measurement, 3, 205231.Google ScholarPubMed
Smith, S. C. et al. (2005). Measurement of health-related quality of life for people with dementia: development of a new instrument (DEMQOL) and an evaluation of current methodology. Health Technolology Assessment, 9, liv.Google Scholar
Smyth, R., Nielsen, I. and Zhai, Q. (2010). Personal well-being in urban China. Social Indicators Research, 95, 231252. doi: 10.1007/s11205-009-9457-2.CrossRefGoogle Scholar
Tennant, A. and Conaghan, P. G. (2007). The Rasch measurement model in rheumatology: what is it and why use it? When should it be applied, and what should one look for in a Rasch paper? Arthritis and Rheumatism, 57, 13581362. doi: 10.1002/art.23108CrossRefGoogle Scholar
Tennant, A., McKenna, S. P. and Hagell, P. (2004). Application of Rasch analysis in the development and application of quality of life instruments. Value in Health, 7, 2226.CrossRefGoogle ScholarPubMed
Tiliouine, H., Cummins, R. and Davern, M. (2006). Measuring wellbeing in developing countries: the case of Algeria. Social Indicators Research, 75, 130. doi: 10.1007/s11205-004-2012-2.CrossRefGoogle Scholar
Wills, E. (2009). Spirituality and subjective well-being: evidences for a new domain in the Personal Well-Being index. Journal of Happiness Studies, 10, 4969. doi: 10.1007/s10902-007-9061-6.CrossRefGoogle Scholar
Zigmond, A. S. and Snaith, R. P. (1983). The Hospital Anxiety and Depression Scale. Acta Psychiatrica Scandinavica, 67, 361370.CrossRefGoogle ScholarPubMed