Responsiveness: a reinvention of the wheel?

Health and Quality of Life Outcomes

Aeilko H Zwinderman²  Mirjam A Sprangers¹  Robert Lindeboom² 

[1] Medical Psychology, Academic Medical Center, Amsterdam, the Netherlands;Departments of Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam, the Netherlands

关键词: reliability;    scale evaluation;    psychometrics;    effect size;    questionnaires;    quality of life;   

Others  :  1216911
DOI  :  10.1186/1477-7525-3-8

 received in 2004-11-22, accepted in 2005-02-03,  发布年份 2005

【 摘 要 】

Background

Since the mid eighties, responsiveness is considered to be a separate property of health status questionnaires distinct from reliability and validity. The aim of the study was to assess the strength of the relationship between internal consistency reliability, referring to an instrument's sensitivity to differences in health status among subjects at one point in time, and responsiveness referring to sensitivity to health status changes over time.

Methods

We used three different datasets comprising the scores of patients on the Barthel, the SIP and the GO-QoL instruments at two points in time. The internal consistency was reduced stepwise by removing the item that contributed most to a scale's reliability. We calculated the responsiveness expressed by the Standardized Response Mean (SRM) on each set of remaining items. The strength of the relationship between the thus obtained internal consistency coefficients and SRMs was quantified by Spearman rank correlation coefficients.

Results

Strong to perfect correlations (0.90 – 1.00) was found between internal consistency coefficients and SRMs for all instruments indicating, that the two can be used interchangeably.

Conclusion

The results contradict the conviction that responsiveness is a separate psychometric property. The internal consistency coefficient adequately reflects an instrument's potential sensitivity to changes over time.

【 授权许可】

   
2005 Lindeboom et al; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Guyatt G, Walter S, Norman G: Measuring change over time: assessing the usefulness of evaluative instruments. J Chron Dis 1987, 40:171-178.
• [2]Allen MJ, Yen WM: Introduction to measurement theory. Monterey, CA: Brooks/Cole; 1979.
• [3]Streiner DL, Norman GF: Health measurement scales: a practical guide to their development and use. third edition. Oxford University Press, Oxford; 2003.
• [4]Kwakkel G, Wagenaar RC, Twisk JW, Lankhorst GJ, Koetsier JC: Intensity of leg and arm training after primary middle-cerebral-artery stroke: a randomised trial. Lancet 1999, 354:191-196.
• [5]Plevier CM, Mooy JM, Marang-Van de Mheen PJ, Stouthard ME, Visser MC, Grobbee DE, Gunning-Schepers LJ: Persistent impaired emotional functioning in survivors of a myocardial infarction? Qual Life Res 2001, 10:123-132.
• [6]De Haan RJ, Limburg M, Van der Meulen JH, Jacobs HM, Aaronson NK: Quality of life after stroke. Impact of stroke type and lesion location. Stroke 1995, 26:402-408.
• [7]Vriens EM, Post MW, Jacobs HM, van Huffelen AC, Eikelboom BC: Changes in health-related quality of life after carotid endarterectomy. Eur J Vasc Endovasc Surg 1998, 16:395-400.
• [8]Terwee CB, Dekker FW, Mourits MP, Gerding MN, Baldeschi L, Kalmann R, Prummel MF, Wiersinga WM: Interpretation and validity of changes in scores on the Graves' ophthalmopathy quality of life questionnaire (GO-QOL) after different treatments. Clin Endocrinol (Oxf) 2001, 54:391-398.
• [9]McHorney CA, Tarlov AR: Individual-patient monitoring in clinical practice: are available health status surveys adequate? Qual Life Res 1995, 4:293-307.
• [10]Nunnaly JC: Psychometric theory. McGraw-Hill, New York; 1978.
• [11]Terwee CB, Dekker FW, Wiersinga WM, Prummel MF, Bossuyt PM: On assessing responsiveness of health-related quality of life instruments: guidelines for instrument evaluation. Qual Life Res 2003, 12:349-362.