Quality of Life Research

, Volume 11, Issue 5, pp 437–447

Validation of the KDQOL-SFTM: A dialysis-targeted health measure

  • J.C. Korevaar
  • M.P. Merkus
  • M.A.M. Jansen
  • F.W. Dekker
  • E.W. Boeschoten
  • R.T. Krediet


Background: In evaluations of dialysis therapy, an assessment of health-related quality of life (HRQOL) is often important. The aim of this study was to determine the basic psychometric properties, reliability and validity of the short form of the KDQOLTM i.e. the KDQOL-SFTM, a dialysis-targeted instrument, and to assess its ability to detect changes over time. Methods: In a prospective cohort study (Netherlands Cooperative Study on the Adequacy of Dialysis, NECOSAD), all new adult ESRD patients in 32 different Dutch centers were consecutively enrolled. Demographic, clinical and HRQOL data were obtained 3 and 12 months after the start of chronic dialysis therapy. Results: The reliability of the KDQOL-SFTM was supported by test results that were above the recommended minimal values. Validity of KDQOL-SFTM was confirmed by the hypothesized positive correlations of the overall health rating and renal function, and by the negative correlations between the number of comorbidities and dialysis dose. Moreover, dialysis-targeted dimensions were more sensitive in detecting relevant differences pertaining to kidney diseases than generic dimensions. The KDQOL-SFTM was able to detect clinical changes over time. Conclusions: The psychometric properties of the KDQOL-SFTM were good, and the different dialysis-targeted dimensions were informative with a high reliability and validity. These results support the application of the KDQOL-SFTM in studies evaluating dialysis therapy.

Dialysis ESRD Health-related quality of life KDQOL-SFTM Questionnaire validation 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Merkus MP, Jager KJ, Dekker FW, Boeschoten EW, Stevens P, Krediet RT. Quality of life in patients on chronic dialysis: Self-assessment 3 months after the start of treatment. Am J Kidney Dis 1997; 29: 584-592.Google Scholar
  2. 2.
    Gudex C, Dolan P, Kind P, Williams A. Health state valuations from the general public using the visual analogue scale. Qual Life Res 1996; 5: 521-531.Google Scholar
  3. 3.
    Khan IH, Garratt AM, Kumar A, et al. Patients' perception of health on renal replacement therapy: evaluation using a new instrument. Nephrol Dial Transpl 1995; 10: 684-689.Google Scholar
  4. 4.
    Mingardi G. From the development to the clinical application of a questionnaire on the quality of life in dialysis. The experience of the Italian Collaborative DIA-QOL group. Nephrol Dial Transpl 1998; 13(Suppl 1): 70-75.Google Scholar
  5. 5.
    Korevaar JC, Jansen MAM, Merkus MP, Dekker FW, Boeschoten EW, Krediet RT. Quality of life in pre-dialysis end-stage renal disease patients at the initiation of dialysis therapy. Periton Dialysis Int 2000; 20: 69-75.Google Scholar
  6. 6.
    Guyatt GH, Feeny DH, Patrick DL. Measuring healthrelatedquality of life. Ann Intern Med 1993; 118: 622-629.Google Scholar
  7. 7.
    Hays RD, Kallich JD, Mapes DL, Coons SJ, Carter WB. Development of the kidney disease quality of life (KDQOLTM) instrument. Qual Life Res 1994; 3: 329-338.Google Scholar
  8. 8.
    Hays RD, et al. Kidney Disease Quality of Life Short Form (KDQOL-SFTM). Santa Monica, CA: Rand, 1995.Google Scholar
  9. 9.
    Watson PE, Watson ID, Batt RD. Total body water volumes for adult males and females estimated from simple anthropometric measurements. Am J Clin Nutr 1980; 33: 27-39.Google Scholar
  10. 10.
    Daugirdas JT. Second generation logarithmic estimates of single-pool variable volume Kt/V: An analysis of error. J Am Soc Nephrol 1993; 4: 1205-1213.Google Scholar
  11. 11.
    Essink-Bot ML, Stouthard MEA, Bonsel GJ. Generalizability of valuations on health states collectedwith the EuroQol-questionnaire. Economic evaluation 1993; 2: 237-246.Google Scholar
  12. 12.
    Ware JE, Sherbourne CD. The MOS 36-item Short-Form Health Survey (SF-36) I. Conceptual framework anditem selection. Medical Care 1992; 30: 473-483.Google Scholar
  13. 13.
    Aaronson NK, Muller M, Cohen PAD, et al. Translation, validation, and norming of the Dutch language version of the SF-36 health survey in community andchronic disease populations. J Clin Epidemiol 1998; 51: 1055-1068.Google Scholar
  14. 14.
    Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health relatedquality of life measures: Literature review and proposed guidelines. J Clin Epidemiol 1993; 46: 1417-1432.Google Scholar
  15. 15.
    Bullinger M, Alonso J, Apolone G, et al. Translating health status questionnaires andevaluati ng their quality: The IQOLA project approach. J Clin Epidemiol 1998; 51: 913-923.Google Scholar
  16. 16.
    McHorney CA, Ware JE, Lu R, Sherbourne CD. The MOS 36-item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Medical Care 1994; 32: 40-66.Google Scholar
  17. 17.
    Ware JE, Gandek B. Methods for testing data quality, scaling assumptions, andreliability: The IQOLA project approach. J Clin Epidemiol 1998; 51: 945-952.Google Scholar
  18. 18.
    Cronbach LJ. Coefficient alpha andthe internal structure of tests. Psychometrika 1951; 16: 297-334.Google Scholar
  19. 19.
    Nunnally JC. Psychometric Theory. New York: McGraw-Hill, 1978.Google Scholar
  20. 20.
    Shumaker SA, Anderson RT, Czajkowski SM. Quality of life assessments in clinical trials. In: Spilker B (ed) Psychological test andscales. New York: Raven Press, 1990: 95-113.Google Scholar
  21. 21.
    NKF-DOQI. Clinical practice guidelines for hemodialysis and peritoneal dialysis adequacy. National Kidney Foundation. Am J Kidney Dis 1997; 30: S1-S136.Google Scholar
  22. 22.
    Krishner B, Guyatt GH. A methodological framework for assessing health indices. J Chron dis 1985; 38: 27-36.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • J.C. Korevaar
    • 1
  • M.P. Merkus
    • 1
  • M.A.M. Jansen
    • 2
  • F.W. Dekker
    • 3
  • E.W. Boeschoten
    • 2
  • R.T. Krediet
    • 2
  1. 1.Department of Clinical Epidemiology and BiostatisticsUniversity of AmsterdamThe Netherlands
  2. 2.Department of Nephrology, Academic Medical CenterUniversity of AmsterdamThe Netherlands
  3. 3.Department of Clinical Epidemiology, Leiden University Medical CenterUniversity of LeidenThe Netherlands

Personalised recommendations