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Comparison of health-related quality of life measures for chronic renal failure: quality of well-being scale, short-form-6D, and the kidney disease quality of life instrument

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Abstract

Background

Studies have found that health-related quality of life (HRQOL) measurements with different conceptual bases yield widely varying results within the same study sample. Using data from a cohort of patients with chronic kidney failure, the purpose of this study was to compare the Quality of Well-Being Scale-Self-Administered (QWB-SA), the Short-Form-6D (SF-6D), and the Kidney Disease Component Summary (KDCS).

Methods

Baseline data from a multi-site prospective observational study of 322 veterans receiving hemodialysis were analyzed. Descriptive statistics were calculated. Confirmatory factor analysis was conducted to determine how closely the three HRQOL tools reflected the same underlying construct.

Results

Our confirmatory factor analysis offered strong evidence that the subscales of the QWB-SA, SF-6D, and 7-subscale KDCS measured more than one factor in this study sample. In the three-factor model, the SF-6D and 7-subscale KDCS correlated .911 (P < .05), indicating 83% of the variance in the 7-subscale KDCS was correlated with the SF-6D. However, a two-factor model, in which the highly correlated SF-6D and 7-subscale KDCS were combined, fit the data almost as well as the three-factor model.

Conclusion

The three HRQOL measures addressed different underlying HRQOL constructs in this sample. The QWB-SA was significantly different from the SF-6D and KDCS.

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Notes

  1. The data reported here have been supplied by the United States Renal Data System. The interpretation and reporting of these data are the responsibility of the author(s) and in no way should be seen as an official policy or interpretation of the U.S. government.

Abbreviations

CFA:

Confirmatory factor analysis

CKD:

Chronic kidney disease

CRF:

Chronic renal failure

CFI:

Comparative fit index

EQ-5D:

EuroQol instrument

GFI:

Goodness-of-fit index

HRQOL:

Health-related quality of life

HUI:

Health utilities index

ICED:

Index of coexistent disease

IPI:

Index of physical impairment

KDCS:

Kidney disease component summary

KDQOL:

Kidney disease quality of life instrument

KDQOL-SF:

Kidney disease quality of life instrument-short form

NFI:

Normed fit index

NNFI:

Non-normed fit index

QALYs:

Quality-adjusted life years

QOL:

Quality of life

QWB:

Quality of well-being scale

QWB-SA:

Quality of well-being scale-self-administered

RMSEA:

Root-mean-square error of approximation

SF-6D:

Short-form-6D

SF-12:

Short-form-12

SF-36:

Short-form-36

SRMR:

Standardized root-mean-square residual

References

  1. U.S. Renal Data System. (2007). USRDS 2006 annual data report: Atlas of end-stage renal disease in the united states. Resource document. http://www.usrds.org/adr.htm. Accessed 20 June 2007.

  2. Testa, M. A., & Nackley, J. F. (1994). Methods for quality-of-life studies. Annual Review of Public Health, 15, 535–559. doi:10.1146/annurev.pu.15.050194.002535.

    Article  PubMed  CAS  Google Scholar 

  3. Bryan, S., & Longworth, L. (2005). Measuring health-related utility: Why the disparity between EQ-5D and SF-6D? The European Journal of Health Economics, 6(3), 253–260. doi:10.1007/s10198-005-0299-9.

    Article  PubMed  Google Scholar 

  4. Chiang, C. (1965). An index of health: Mathematical models. PHS 1000 HRP-0005421 (pp. 1–25). Washington, DC: Public Health Service Publications.

  5. Korevaar, J. C., Merkus, M. P., Jansen, M. A., Dekker, F. W., Boeschoten, E. W., Krediet, R. T., et al. (2002). Validation of the KDQOL-SF: A dialysis-targeted health measure. Quality of Life Research, 11(5), 437–447. doi:10.1023/A:1015631411960.

    Article  PubMed  CAS  Google Scholar 

  6. Berlim, M. T., Mattevi, B. S., Duarte, A. P., Thome, F. S., Barros, E. J., & Fleck, M. P. (2006). Quality of life and depressive symptoms in patients with major depression and end-stage renal disease: A matched-pair study. Journal of Psychosomatic Research, 61(5), 731–734. doi:10.1016/j.jpsychores.2006.04.011.

    Article  PubMed  Google Scholar 

  7. Guerini, R. D., Mercieri, A., & Yavuzer, G. (2006). Multidimensional health-status assessment of chronic hemodialysis patients: The impact on quality of life. Europa Medicophysica, 42(2), 113–119.

    Google Scholar 

  8. Al-Arabi, S. (2006). Quality of life: Subjective descriptions of challenges to patients with end stage renal disease. Nephrology Nursing Journal: Journal of the American Nephrology Nurses’ Association, 33(3), 285–292.

    Google Scholar 

  9. Drayer, R. A., Piraino, B., Reynolds, C. F., I. I. I., Houck, P. R., Mazumdar, S., Bernardini, J., et al. (2006). Characteristics of depression in hemodialysis patients: Symptoms, quality of life and mortality risk. General Hospital Psychiatry, 28(4), 306–312. doi:10.1016/j.genhosppsych.2006.03.008.

    Article  PubMed  Google Scholar 

  10. Gerard, K., Nicholson, T., Mullee, M., Mehta, R., & Roderick, P. (2004). EQ-5D versus SF-6D in an older, chronically ill patient group. Applied Health Economics and Health Policy, 3(2), 91–102. doi:10.2165/00148365-200403020-00005.

    Article  PubMed  Google Scholar 

  11. Gorodetskaya, I., Zenios, S., McCulloch, C. E., Bostrom, A., Hsu, C. Y., Bindman, A. B., et al. (2005). Health-related quality of life and estimates of utility in chronic kidney disease. Kidney International, 68(6), 2801–2808. doi:10.1111/j.1523-1755.2005.00752.x.

    Article  PubMed  Google Scholar 

  12. Fryback, D. G., Lawrence, W. F., Martin, P. A., Klein, R., & Klein, B. E. (1997). Predicting quality of well-being scores from the SF-36: Results from the Beaver Dam health outcomes study. Medical Decision Making, 17(1), 1–9. doi:10.1177/0272989X9701700101.

    Article  PubMed  CAS  Google Scholar 

  13. Lopes, A. A., Bragg-Gresham, J. L., Goodkin, D. A., Fukuhara, S., Mapes, D. L., Young, E. W., et al. (2007). Factors associated with health-related quality of life among hemodialysis patients in the DOPPS. Quality of Life Research, 16(4), 545–557. doi:10.1007/s11136-006-9143-7.

    Article  PubMed  Google Scholar 

  14. Parsons, T. L., Toffelmire, E. B., & King-VanVlack, C. E. (2006). Exercise training during hemodialysis improves dialysis efficacy and physical performance. Archives of Physical Medicine and Rehabilitation, 87(5), 680–687. doi:10.1016/j.apmr.2005.12.044.

    Article  PubMed  Google Scholar 

  15. Hynes, D. M., Stroupe, K. T., Kaufman, J. S., Reda, D. J., Peterman, A., Browning, M. M., et al. (2006). Adherence to guidelines for ESRD anemia management. American Journal of Kidney Diseases, 47(3), 455–461. doi:10.1053/j.ajkd.2005.11.012.

    Article  PubMed  Google Scholar 

  16. Kaplan, R. M., Sieber, W. J., & Ganiats, T. G. (1997). The quality of well-being scale: Comparison of the interviewer-administered version with a self-administered questionnaire. Psychology & Health, 12, 783–791. doi:10.1080/08870449708406739.

    Article  Google Scholar 

  17. Kaplan, R. M., & Anderson, J. P. (1988). A general health policy model: Update and applications. Health Services Research, 23(2), 203–235.

    PubMed  CAS  Google Scholar 

  18. Kaplan, R. M., Ganiats, T. G., Sieber, W. J., & Anderson, J. P. (1998). The quality of well-being scale: Critical similarities and differences with SF-36. International Journal for Quality in Health Care, 10(6), 509–520. doi:10.1093/intqhc/10.6.509.

    Article  PubMed  CAS  Google Scholar 

  19. Sieber, W. J., David, K. M., Adams, J. E., Kaplan, R. M., & Ganiats, T. G. (2000). Assessing the impact of migraine on health-related quality of life: An additional use of the quality of well-being scale-self-administered. Headache, 40(8), 662–671. doi:10.1046/j.1526-4610.2000.040008662.x.

    Article  PubMed  CAS  Google Scholar 

  20. Tabaei, B. P., Shill-Novak, J., Brandle, M., Burke, R., Kaplan, R. M., & Herman, W. H. (2004). Glycemia and the quality of well-being in patients with diabetes. Quality of Life Research, 13(6), 1153–1161. doi:10.1023/B:QURE.0000031336.81580.52.

    Article  PubMed  CAS  Google Scholar 

  21. Mancino, M. J., Pyne, J. M., Tripathi, S., Constans, J., Roca, V., & Freeman, T. (2006). Quality-adjusted health status in veterans with posttraumatic stress disorder. The Journal of Nervous and Mental Disease, 194(11), 877–879. doi:10.1097/01.nmd.0000244686.79689.21.

    Article  PubMed  Google Scholar 

  22. Brazier, J., Usherwood, T., Harper, R., & Thomas, K. (1998). Deriving a preference-based single index from the UK SF-36 health survey. Journal of Clinical Epidemiology, 51(11), 1115–1128. doi:10.1016/S0895-4356(98)00103-6.

    Article  PubMed  CAS  Google Scholar 

  23. Brazier, J., Roberts, J., & Deverill, M. (2002). The estimation of a preference-based measure of health from the SF-36. Journal of Health Economics, 21(2), 271–292. doi:10.1016/S0167-6296(01)00130-8.

    Article  PubMed  Google Scholar 

  24. Brazier, J. E., & Roberts, J. (2004). The estimation of a preference-based measure of health from the SF-12. Medical Care, 42(9), 851–859. doi:10.1097/01.mlr.0000135827.18610.0d.

    Article  PubMed  Google Scholar 

  25. Ware, J., & Sherbourne, C. (1992). The MOS 36-item short-form health survey (SF-36). Medical Care, 30(6), 473–483. doi:10.1097/00005650-199206000-00002.

    Article  PubMed  Google Scholar 

  26. Ware, J. E., Kosinski, M., Turner-Bowker, D. M., & Gandek, B. (2002). How to score version 2 of the SF-12 health survey. Massachusetts: QualityMetric Incorporated.

    Google Scholar 

  27. Hatoum, H. T., Brazier, J. E., & Akhras, K. S. (2004). Comparison of the HUI3 with the SF-36 preference based SF-6D in a clinical trial setting. Value in Health, 7(5), 602–609. doi:10.1111/j.1524-4733.2004.75011.x.

    Article  PubMed  Google Scholar 

  28. O’Brien, B. J., Spath, M., Blackhouse, G., Severens, J. L., Dorian, P., & Brazier, J. (2003). A view from the bridge: Agreement between the SF-6D utility algorithm and the health utilities index. Health Economics, 12(11), 975–981. doi:10.1002/hec.789.

    Article  PubMed  Google Scholar 

  29. McDonough, C. M., Grove, M. R., Tosteson, T. D., Lurie, J. D., Hilibrand, A. S., & Tosteson, A. N. (2005). Comparison of EQ-5D, HUI, and SF-36-derived societal health state values among spine patient outcomes research trial (SPORT) participants. Quality of Life Research, 14(5), 1321–1332. doi:10.1007/s11136-004-5743-2.

    Article  PubMed  Google Scholar 

  30. Barton, G. R., Bankart, J., & Davis, A. C. (2005). A comparison of the quality of life of hearing-impaired people as estimated by three different utility measures. International Journal of Audiology, 44(3), 157–163. doi:10.1080/14992020500057566.

    Article  PubMed  Google Scholar 

  31. Longworth, L., & Bryan, S. (2003). An empirical comparison of EQ-5D and SF-6D in liver transplant patients. Health Economics, 12(12), 1061–1067. doi:10.1002/hec.787.

    Article  PubMed  Google Scholar 

  32. Stavem, K., Froland, S. S., & Hellum, K. B. (2005). Comparison of preference-based utilities of the 15D, EQ-5D and SF-6D in patients with HIV/AIDS. Quality of Life Research, 14(4), 971–980. doi:10.1007/s11136-004-3211-7.

    Article  PubMed  Google Scholar 

  33. Petrou, S., & Hockley, C. (2005). An investigation into the empirical validity of the EQ-5d and SF-6D based on hypothetical preferences in a general population. Health Economics, 14(11), 1169–1189. doi:10.1002/hec.1006.

    Article  PubMed  Google Scholar 

  34. Hays, R. D., Kallich, J. D., Mapes, D. L., Coons, S. J., & Carter, W. B. (1994). Development of the kidney disease quality of life (KDQOL) instrument. Quality of Life Research, 3(5), 329–338. doi:10.1007/BF00451725.

    Article  PubMed  CAS  Google Scholar 

  35. Hays, R. D., Kallich, J. D., Mapes, D. L., Coons, H. L., & Carter, W. B. (1995). Kidney disease quality of life short form (KDQOL-SF). Santa Monica, CA: Rand.

    Google Scholar 

  36. Mapes, D. L., Bragg-Gresham, J. L., Bommer, J., Fukuhara, S., McKevitt, P., Wikstrom, B., et al. (2004). Health-related quality of life in the dialysis outcomes and practice patterns study (DOPSS). American Journal of Kidney Diseases, 44(5 Suppl 2), 54–60.

    Article  PubMed  Google Scholar 

  37. Paniagua, R., Amato, D., Vonesh, E., Guo, A., Mujais, S., & Mexican Nephrology Collaborative Study Group. (2005). Health-related quality of life predicts outcomes but is not affected by peritoneal clearance: The ademex trial. Kidney International, 67(3), 1093–1104. doi:10.1111/j.1523-1755.2005.00175.x.

    Article  PubMed  Google Scholar 

  38. Lopes, A. A., Bragg-Gresham, J. L., Satayathum, S., McCullough, K., Pifer, T., Goodkin, D. A., et al. (2003). Health-related quality of life and associated outcomes among hemodialysis patients of different ethnicities in the United States: The dialysis outcomes and practice patterns study (DOPPS). American Journal of Kidney Diseases, 41(3), 605–615. doi:10.1053/ajkd.2003.50122.

    Article  PubMed  Google Scholar 

  39. van Janssen, D. K., Heylen, M., Mets, T., & Verbeelen, D. (2004). Evaluation of functional and mental state and quality of life in chronic haemodialysis patients. International Urology and Nephrology, 36(2), 263–267. doi:10.1023/B:UROL.0000034653.59183.77.

    Article  Google Scholar 

  40. Bakewell, A. B., Higgins, R. M., & Edmunds, M. E. (2002). Quality of life in peritoneal dialysis patients: Decline over time and association with clinical outcomes. Kidney International, 61(1), 239–248. doi:10.1046/j.1523-1755.2002.00096.x.

    Article  PubMed  Google Scholar 

  41. Kawauchi, A., Inoue, Y., Hashimoto, T., Tachibana, N., Shirakawa, S., Mizutani, Y., et al. (2006). Restless legs syndrome in hemodialysis patients: Health-related quality of life and laboratory data analysis. Clinical Nephrology, 66(6), 440–446.

    PubMed  CAS  Google Scholar 

  42. Vazquez, I., Valderrabano, F., Fort, J., Jofre, R., Lopez-Gomez, J. M., Moreno, F., et al. (2005). Psychosocial factors and health-related quality of life in hemodialysis patients. Quality of Life Research, 14(1), 179–190. doi:10.1007/s11136-004-3919-4.

    Article  PubMed  Google Scholar 

  43. Manns, B., Johnson, J. A., Taub, K., Mortis, G., Ghali, W. A., & Donaldson, C. (2003). Quality of life in patients treated with hemodialysis or peritoneal dialysis: What are the important determinants? Clinical Nephrology, 60(5), 341–351.

    PubMed  CAS  Google Scholar 

  44. Arbor Research Collaborative for Health. (2007). Dialysis outcomes and practice patterns study. Resource document.

  45. Yuan, Y. (2000). Multiple imputation for missing data: Concepts and new developments. P267-25. Rockville, MD: SAS Institute.

  46. Carmines, E. G., & Zeller, R. A. (1978). Reliability and validity assessment. Beverly Hills, CA: Sage.

    Google Scholar 

  47. McDonald, R. P. (1999). Test theory: A unified treatment. Mahwah, NJ: Erlbaum.

    Google Scholar 

  48. Joreskog, K. G., & Sorbom, D. G. (1996). LISREL 8: User’s reference guide. Chicago: Scientific Software.

    Google Scholar 

  49. Bentler, P. M. (1983). Some contributions to efficient statistics in structural models: Specification and estimation of moment structures. Psychometrika, 48(4), 493–517. doi:10.1007/BF02293875.

    Article  Google Scholar 

  50. Steiger, J. H., & Lind, J. C. (1980). Statistically based tests for the number of common factors. Paper presented at the Annual Spring Meeting of the Psychometric Society, Iowa City. http://www.statpower.net/Steiger%20Biblio/Steiger-Lind%201980.pdf.

  51. Bentler, P. (1995). EQS structural equations program manual. Encino, CA: Multivariate Software.

    Google Scholar 

  52. Bentler, P. M. (1990). Comparative fit indexes in structural models. Psychological Bulletin, 107(2), 238–246. doi:10.1037/0033-2909.107.2.238.

    Article  PubMed  CAS  Google Scholar 

  53. Bentler, P. M., & Bonett, D. G. (1980). Significance tests and goodness of fit in the analysis of covariance structures. Psychological Bulletin, 88(3), 588–606. doi:10.1037/0033-2909.88.3.588.

    Article  Google Scholar 

  54. Hu, L., & Bentler, P. M. (1998). Fit indices in covariance structure modeling: Sensitivity to underparameterized model misspecification. Psychological Methods, 3(4), 424–453. doi:10.1037/1082-989X.3.4.424.

    Article  Google Scholar 

  55. Hu, L. T., & Bentler, P. M. (1999). Cutoff criteria for fit indexes in covariance structure analysis: Conventional criteria versus new alternatives. Structural Equation Modeling, 6(1), 1–55.

    Article  Google Scholar 

  56. Browne, M., & Cudeck, R. (1993). Alternative ways of assessing model fit. In K. Bollen & J. Long (Eds.), Testing structural equation models (pp. 136–162). Newbury Park, CA: Sage.

    Google Scholar 

  57. Mosier, C. I. (1943). On the reliability of a weighted composite. Psychometrika, 8, 161–168. doi:10.1007/BF02288700.

    Article  Google Scholar 

  58. Bentler, P. M., & Mooijaart, A. (1989). Choice of structural model via parsimony: A rationale based on precision. Psychological Bulletin, 106(2), 315–317. doi:10.1037/0033-2909.106.2.315.

    Article  PubMed  CAS  Google Scholar 

  59. Smith, K. W., Avis, N. E., & Assmann, S. F. (1999). Distinguishing between quality of life and health status in quality of life research: A meta-analysis. Quality of Life Research, 8, 447–459. doi:10.1023/A:1008928518577.

    Article  PubMed  CAS  Google Scholar 

  60. Coons, S. J., & Kaplan, R. M. (1993). Quality of life assessment: Understanding its use as an outcome measure. Hospital Formulary, 28(5), 486–490.

    PubMed  CAS  Google Scholar 

  61. Garratt, A., Schmidt, L., Mackintosh, A., & Fitzpatrick, R. (2002). Quality of life measurement: Bibliographic study of patient assessed health outcome measures. BMJ (Clinical Research Ed.), 324(7351), 1417. doi:10.1136/bmj.324.7351.1417.

    Article  Google Scholar 

  62. Deverill, M., Brazier, J., Green, C., & Booth, A. (1998). The use of QALY and non-QALY measures of health-related quality of life. Assessing the state of the art. PharmacoEconomics, 13(4), 411–420. doi:10.2165/00019053-199813040-00004.

    Article  PubMed  CAS  Google Scholar 

  63. Naughton-Collins, M., Walker-Corkery, E., & Barry, M. J. (2004). Health-related quality of life, satisfaction, and economic outcome measures in studies of prostate cancer screening and treatment, 1990–2000. Journal of the National Cancer Institute. Monographs, 33, 78–101. doi:10.1093/jncimonographs/lgh016.

    Article  Google Scholar 

  64. Kutner, N., Bowles, T., Zhang, R., Huang, Y., & Pastan, S. (2008). Dialysis facility characteristics and variation in employment rates: A national study. Clinical Journal of the American Society of Nephrology; CJASN, 3(1), 111–116. doi:10.2215/CJN.02990707.

    Article  PubMed  Google Scholar 

  65. Bohlke, M., Marini, S., Gomes, R., Terhorst, L., Rocha, M., Poli De Figueiredo, C. E., et al. (2008). Predictors of employment after successful kidney transplantation—a population-based study. Clinical Transplantation, 22, 405–410.

    PubMed  Google Scholar 

  66. Bryant, F. B., Yarnold, P. R., & Michelson, E. A. (1999). Statistical methodology: VIII. Using confirmatory factor analysis (CFA) in emergency medicine research. Academic Emergency Medicine, 6(1), 54–66. doi:10.1111/j.1553-2712.1999.tb00096.x.

    Article  PubMed  CAS  Google Scholar 

  67. Boonen, A., van der Heijde, D., Landewe, R., van Tubergen, A., Mielants, H., Dougados, M., & van der Linden, S. (2007). How do the EQ-5D, SF-6D and the well-being rating scale compare in patients with ankylosing spondylitis? Annals of the Rheumatic Diseases, 66, 771–777.

    Article  PubMed  Google Scholar 

  68. Brazier, J. E., Tsuchiya, A., Roberts, J., & Busschbach, J. (2004). A comparison of the EQ-5D and the SF-6D across seven patient groups. Health Economics, 13, 873–884.

    Article  PubMed  Google Scholar 

  69. Gabriel, S. E., Kneeland, T. S., Melton, L. J., Moncur, M. M., Ettinger, B., Tosteson, A. N. A. (1999). Health-related quality of life in economic evaluations for osteoporosis: whose values should we use? Medical Decision Making, 19, 141–148.

    Article  PubMed  CAS  Google Scholar 

  70. Marra, C. A., Rashidi, A. A., Guh, D., Kopec, J. A., Abrahamowicz, M., Esdaile, J. M., et al. (2005). Are indirect utility measures reliable and responsive in rheumatoid arthritis patients? Quality of Life Research, 14(5), 1333–1344.

    Article  PubMed  Google Scholar 

  71. Pickard, A. S., Johnson, J. A., & Feeny, D. H. (2005). Responsiveness of generic health-related quality of life measures in stroke. Quality of Life Research, 14(1), 207–219.

    Article  PubMed  Google Scholar 

  72. Siderowf, A., Ravina, B., & Glick, H. (2002). Preference-based quality-of-life in patients with Parkinson’s disease. Neurology, 59, 103–108.

    PubMed  Google Scholar 

  73. van Stel, H. F., & Buskens, E. (2006). Comparison of the SF-6D and the EQ-5D in patients with coronary heart disease. Health Quality of Life Outcomes, 4, 20.

    Article  Google Scholar 

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Acknowledgments

This research was supported by the U.S. Department of Veterans Affairs, Veterans Health Administration, Health Services Research and Development Service—“Cost and Effectiveness of End-Stage Renal Disease Care” (D. Hynes, principal investigator) (ECI-20-016). Dr. Hynes is also supported by a 5-year Veterans Affairs Health Services Research and Development Service Research Career Scientist Award. Dr. Saban is supported by a 3-year Veterans Affairs Health Services Research and Development Service Postdoctoral Fellowship (TPN 42-001). We also kindly thank Madeline Thornton for her assistance in formatting the path diagrams. Lastly, we would like to express our gratitude to the anonymous manuscript reviewers whose thought-provoking feedback helped strengthen this paper.

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Appendix Comparison of HRQOL results from selected studies

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Saban, K.L., Stroupe, K.T., Bryant, F.B. et al. Comparison of health-related quality of life measures for chronic renal failure: quality of well-being scale, short-form-6D, and the kidney disease quality of life instrument. Qual Life Res 17, 1103–1115 (2008). https://doi.org/10.1007/s11136-008-9387-5

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