Abstract
Objectives
To predict the risk of future unfavourable health outcomes in older people it is common to assess the level of both basic and instrumental activities of daily living. To accomplish this, the commonly used Katz-6 and the Lawton IADL questionnaires can be combined to form the ‘Modified Katz ADL’ scale, also known as the Katz-15 scale. So far, the validity and reliability of the Katz-15 scale is unknown. The objective of the current study is to investigate how well the Katz-15 is able to predict future unfavorable health outcomes and how this is related to the existing Katz-6 scale.
Design
We performed a follow-up study using data from a group of 60 year and older participants from a large Dutch clinical trial.
Participants
We included 2321 participants in the analysis. The average age of the study population was 74 years and 44% was male.
Measurements
We studied the relation between the Katz-15 scale and a number of unfavourable health outcomes, such as hospitalization, admission to a nursing home, admission to a home for the aged and death within one year of follow-up.
Results
We found the Katz-15 to be both internally consistent and strongly associated with quality of life measures. We observed moderate to strong associations between the Katz-15 and the unfavourable health outcomes All associations studied were stronger for the Katz-15 scale as compared to the Katz-6 scale.
Conclusion
The results of our study indicate that the Katz-15 scale is able to reliably and validly predict future unfavorable health outcomes. This makes the scale a valuable measure in determining both basic and instrumental activities of daily living
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References
United Nations: Department of Economic and Social Affairs. World Population Ageing 2007., 2007 Edition ed., United Nations Publications.
Katz, S., Ford, A. B., Moskowitz, R. W., Jackson, B. A. & Jaffe, M. W. Studies of Illness in the Aged. JAMA: The Journal of the American Medical Association 1963;185: 914–919.
Lawton, M. P. & Brody, E. M. Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist. 1963;9: 179–186.
Thomas, V. S., Rockwood, K. & McDowell, I. Multidimensionality in Instrumental and Basic Activities of Daily Living. Journal of Clinical Epidemiology 1998;51: 315–321.
Suijker, J. J., Buurman, B. M., ter, R. G., van, R. M., de Haan, R. J., de Rooij, S. E. & Moll van Charante, E. P. Comprehensive geriatric assessment, multifactorial interventions and nurse-led care coordination to prevent functional decline in community-dwelling older persons: protocol of a cluster randomized trial. BMC. Health Serv. Res. 2012;12:85. doi: 10.1186/1472-6963-12–85.:85–12.
Makai, P., Koopmanschap, M. A., Brouwer, W. B. & Nieboer, A. A. A validation of the ICECAP-O in a population of post-hospitalized older people in the Netherlands. Health Qual. Life Outcomes. 2013;11:57. doi: 10.1186/1477-7525-11-57.:57–11.
Laan, W., Bleijenberg, N., Drubbel, I., Numans, M. E., de Wit, N. J. & Schuurmans, M. J. Factors associated with increasing functional decline in multimorbid independently living older people. Maturitas. 2013;75: 276–281.
den Ouden, M. E. M., Schuurmans, M. J., Mueller-Schotte, S., Brand, J. S. & van der Schouw, Y. T. Domains Contributing to Disability in Activities of Daily Living. Journal of the American Medical Directors Association 2013;14: 18–24.
Ruikes, F. G., Meys, A. R., van de, W. G., Akkermans, R. P., van Gaal, B. G., Zuidema, S. U., Schers, H. J., van A. T. & Koopmans, R. T. The CareWell-primary care program: design of a cluster controlled trial and process evaluation of a complex intervention targeting community-dwelling frail elderly. BMC. Fam. Pract. 2012;13:115. doi: 10.1186/1471-2296-13-115.:115-13.
ZonMw. The National Care for the Elderly Programme — abridged programme document. 1–8. 2008.
Weinberger, M., Samsa, G. P., Schmader, K., Greenberg, S. M., Carr, D. B. & Wildman, D. S. Comparing proxy and patients’ perceptions of patients’ functional status: results from an outpatient geriatric clinic. J. Am. Geriatr. Soc. 1992;40: 585–588.
Bleijenberg, N., Drubbel, L, ten Dam, V., Numans, M., Schuurmans, M. & de Wit, N. Proactive and integrated primary care for frail older people: Design and methodological challenges of the Utrecht Primary care PROactive Frailty Intervention Trial (U-PROFIT). BMC Geriatrics 2012;12: 16.
Crocker, L. M. & Algina, J. Introduction to classical and modern test theory. Holt, Rinehart, and Winston, New York, 1986.
Ware, J. E., Jr. & Sherbourne, C. D. The MOS 36-Item Short-Form Health Survey (SF-36): I. Conceptual Framework and Item Selection. Medical Care 1992;30: 473–483.
Krabbe, P. F. M., Stouthard, M. E. A., Essink-Bot, M. L. & Bonsel, G. J. The Effect of Adding a Cognitive Dimension to the EuroQol Multiattribute Health-Status Classification System. Journal of Clinical Epidemiology 1999;52: 293–301.
Drubbel, I., de Wit, N. J., Bleijenberg, N., Eijkemans, R. J. C, Schuurmans, M. J. & Numans, M. E. Prediction of Adverse Health Outcomes in Older People Using a Frailty Index Based on Routine Primary Care Data. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 2013;68: 301–308.
Lakhan, P., Jones, M., Wilson, A. & Gray, L. C. The decline in Activities of Daily Living at Discharge (DADLD) index: stratifying patients at lower and higher risk. J. Nutr. Health Aging. 2012;16: 919–924.
Mahoney, F. I. & Barthel, D. W. Functional evaluation: The BARTHEL index. Md State Med. J. 1965;14:61–5.:61–65.
Keith, R. A., Granger, C. V., Hamilton, B. B. & Sherwin, F. S. The functional independence measure: a new tool for rehabilitation. Adv. Clin. Rehabil. 1987;1:6–18.:6–18.
Hirsch, C. H., Sommers, L., Olsen, A., Mullen, L. & Winograd, C. H. The natural history of functional morbidity in hospitalized older patients. J. Am. Geriatr. Soc. 1990;38: 1296–1303.
Donaldson, S. W., Wagner, C. C. & Gresham, G. E. A unified ADL evaluation form. Arch. Phys. Med. Rehabil. 1973;54: 175–179.
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Laan, W., Zuithoff, N.P.A., Drubbel, I. et al. Validity and reliability of the Katz-15 scale to measure unfavorable health outcomes in community-dwelling older people. J Nutr Health Aging 18, 848–854 (2014). https://doi.org/10.1007/s12603-014-0558-5
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DOI: https://doi.org/10.1007/s12603-014-0558-5