Top

Gepubliceerd in:

01-08-2007 | Original Paper

Reliability, validity, and minimally important differences of the SF-6D in systemic sclerosis

Auteurs: Dinesh Khanna, Daniel E. Furst, Weng Kee Wong, Joel Tsevat, Philip J. Clements, Grace S. Park, Arnold E. Postlethwaite, Mansoor Ahmed, Shaari Ginsburg, Ron D. Hays, for the Scleroderma Collagen Type 1 Study Group

Gepubliceerd in: Quality of Life Research | Uitgave 6/2007

Abstract

ObjectivesTo evaluate the reliability and validity and estimate the minimally important difference (MID) for the SF-6D in patients with systemic sclerosis (SSc). Subjects We used data from two clinical studies to analyze the SF-6D in patients with SSc: Study 1 was a cross-sectional observational study (N = 107) designed to assess three direct preference measures—the rating scale, time trade-off, and standard gamble (SG) in patients with diffuse SSc and limited SSc, and Study 2 was a 12-month randomized, placebo-controlled, clinical trial (N = 168) assessing oral bovine collagen versus placebo in diffuse SSc. Methods We assessed the test–retest reliability of the SF-6D in Study 2 over a mean (SD) 4.8 (3.0)-week interval and the agreement between the SF-6D and direct preference measures in Study 1 using intraclass correlations (ICC). The MID was estimated using three different anchors—the SF-36 change in health item (patients who answered “somewhat better” formed the MID group), the Health Assessment Questionnaire-Disability Index (HAQ-DI; change of ≥0.14 and ≥0.22) and the skin score (change of ≥5.3). Results The mean (SD) SF-6D scores were 0.61 (0.12) in Study 1 and 0.64 (0.13) in Study 2. Test–retest reliability for the SF-6D was high (ICC = 0.82 [95% CI: 0.76, 0.87]). Agreement between the SF-6D and three direct preferences measures was poor to moderate (0.16–0.52). The MID estimate for the SF-6D using the change in SF-36 item −0.012 and this level of change was similar to the no change group. The mean MID estimate for the SF-6D improvement using the HAQ-DI and skin score as anchors was 0.035 (effect size of 0.27). Conclusion This is the first study to assess the SF-6D in SSc. The SF-6D is reliable and valid in patients with SSc. We provide MID estimates that can aid in calculating sample size for clinical trials involving patients with diffuse SSc.

vorige artikel Health related quality of life in different states of breast cancer

volgende artikel Rod O’Connor: Measuring quality of life in health

Mayes, M. D., Lacey, J. V., Jr., Beebe-Dimmer, J., Gillespie, B. W., Cooper, B., & Laing, T. J., et al. (2003). Prevalence, incidence, survival, and disease characteristics of systemic sclerosis in a large US population. Arthritis and Rheumatism, 48(8), 2246–2255.PubMedCrossRef

Clements, P. J. (2000). Systemic sclerosis (scleroderma) and related disorders: Clinical aspects. Baillieres Best Practice & Research Clinical Rheumatology, 14(1), 1–16.CrossRef

Charles, C., Clements, P., & Furst, D. E. (2006). Systemic sclerosis: hypothesis-driven treatment strategies. Lancet, 367(9523), 1683–1691.PubMedCrossRef

Altman, R. D., Medsger, T. A., Jr., Bloch, D. A., & Michel, B. A. (1991). Predictors of survival in systemic sclerosis (scleroderma). Arthritis and Rheumatism, 34(4), 403–413.PubMedCrossRef

Malcarne, V. L. (2004). Psychological adjustment in systemic sclerosis. In P. J. Clements & D. E. Furst (Eds.), Systemic sclerosis (pp. 331–350). Philadelphia: Lippincott Williams and Wilkins.

Khanna, D. (2006). Health-related quality of life: A primer with focus on scleroderma. Scleroderma Care and Research, 3(2), 3–13 (Accessed at http://www.sctconline.org/pdfs/SCARV3N2.pdf on March 2nd, 2007).

Ware, J., Kosinski, M., & Dewey, J. (2000). How to score version two of the SF-36 health survey. Lincoln, RI: Quality Metric Incorporated.

Fries, J. F., Spitz, P., Kraines, R. G., & Holman, H. R. (1980). Measurement of patient outcome in arthritis. Arthritis and Rheumatism, 23(2), 137–145.PubMedCrossRef

Torrance, G. (1986). Measurement of health state utilities for economic appraisal. Journal of Health Economics, 5, 1–30.PubMedCrossRef

10.

Von Neumann, J., & Morgenstern, O. (1953). Theory of games and economic behavior. New York: Wiley.

11.

Froberg, D. G., & Kane, R. L. (1989). Methodology for measuring health-state preferences–II: Scaling methods. Journal of Clinical Epidemiology, 42(5), 459–471.PubMedCrossRef

12.

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.PubMedCrossRef

13.

Khanna, D., Ahmed, M., Furst, D. E., Ginsburg, S. S., Park, G. S., & Hornung, R., et al. (2007). Health values of patients with systemic sclerosis. Arthritis and Rheumatism, 57(1), 86–93.PubMedCrossRef

14.

Jaeschke, R., Singer, J., & Guyatt, G. H. (1989). Measurement of health status. Ascertaining the minimal clinically important difference. Controlled Clinical Trials, 10(4), 407–415.PubMedCrossRef

15.

van Walraven, C., Mahon, J. L., Moher, D., Bohm, C., & Laupacis, A. (1999). Surveying physicians to determine the minimal important difference: Implications for sample-size calculation. Journal of Clinical Epidemiology, 52(8), 717–723.PubMedCrossRef

16.

Hays, R. D., Farivar, S., & Liu, H. (2005). Approaches and recommendations for estimating minimally important differences for health-related quality of life measures. COPD: Journal of Chronic Obstructive Pulmonary Disease, 2, 63–67.

17.

Preliminary criteria for the classification of systemic sclerosis (scleroderma). (1980). Subcommittee for scleroderma criteria of the American Rheumatism Association Diagnostic and Therapeutic Criteria Committee. Arthritis and Rheumatism, 23(5), 581–590.CrossRef

18.

Postlethwaite, A., Furst, D., Wong, W. K., & Clements, P. (2005). Oral tolerance (OT). Induction to type I collagen (CI) significantly reduces the skin score in patients with diffuse systemic sclerosis (SSc) with late-phase disease. Results of a NIAMS/NIAID multicenter phase II placebo-controlled double blind clinical trial. Arthritistis and Rheumatism [Abstract].

19.

Clements, P., Lachenbruch, P., Siebold, J., White, B., Weiner, S., & Martin, R., et al. (1995). Inter and intraobserver variability of total skin thickness score (modified Rodnan TSS) in systemic sclerosis. The Journal of Rheumatology, 22(7), 1281–1285.PubMed

20.

Crapo, R. O., Morris, A. H., & Gardner, R. M. (1981). Reference spirometric values using techniques and equipment that meet ATS recommendations. The American Review of Respiratory Disease, 123(6), 659–664.PubMed

21.

Khanna, D., Furst, D. E., Clements, P. J., Park, G. S., Hays, R. D., & Yoon, J., et al. (2005). Responsiveness of the SF-36 and the Health Assessment Questionnaire Disability Index in a systemic sclerosis clinical trial. Journal of Rheumatology, 32(5), 832–840.PubMed

22.

Steen, V. D., & Medsger, T. A., Jr. (1997). The value of the Health Assessment Questionnaire and special patient-generated scales to demonstrate change in systemic sclerosis patients over time. Arthritis and Rheumatism, 40(11), 1984–1991.PubMedCrossRef

23.

UMaker User’s Manual. (1999). UMDNJ Technical Report.

24.

Arias, E. (2004). United States life tables, 2002. National Vital Statistics Reports, 53(6), 1–38.

25.

Nunnally, J. (1978). Psychometric theory. New York: McGraw-Hill.

26.

Franzblau, A. (1958). A primer of statistics for non-statisticians. New York: Brace & World.

27.

Khanna, D., Clements, P. J., Furst, D. E., Chon, Y., Elashoff, R., & Roth, M. D., et al. (2005). Correlation of the degree of dyspnea with health-related quality of life, functional abilities, and diffusing capacity for carbon monoxide in patients with systemic sclerosis and active alveolitis: Results from the Scleroderma Lung Study. Arthritis and Rheumatism, 52(2), 592–600.PubMedCrossRef

28.

Clements, P. J., Wong, W. K., Hurwitz, E. L., Furst, D. E., Mayes, M., & White, B., et al. (2001). The Disability Index of the Health Assessment Questionnaire is a predictor and correlate of outcome in the high-dose versus low-dose penicillamine in systemic sclerosis trial. Arthritis and Rheumatism, 44(3), 653–661.PubMedCrossRef

29.

Osoba, D., Bezjak, A., Brundage, M., Zee, B., Tu, D., & Pater, J. (2005). Analysis and interpretation of health-related quality-of-life data from clinical trials: Basic approach of The National Cancer Institute of Canada Clinical Trials Group. European Journal of Cancer, 41(2), 280–287.PubMedCrossRef

30.

Cole, J. C., Khanna, D., Clements, P. J., Seibold, J. R., Tashkin, D. P., & Paulus, H. E., et al. (2006). Single-factor scoring validation for the Health Assessment Questionnaire-Disability Index (HAQ-DI) in patients with systemic sclerosis and comparison with early rheumatoid arthritis patients. Quality of Life Research, 15(8), 1383–1394.PubMedCrossRef

31.

Wells, G. A., Tugwell, P., Kraag, G. R., Baker, P. R., Groh, J., & Redelmeier, D. A. (1993). Minimum important difference between patients with rheumatoid arthritis: The patient’s perspective. Journal of Rheumatology, 20(3), 557–560.PubMed

32.

Khanna, D., Furst, D. E., Hays, R. D., Park, G. S., Wong, W. K., & Seibold, J. R., et al. (2006, October). Minimally important difference in diffuse systemic sclerosis – results from the d-penicillamine study. Annals of the Rheumatic Diseases, 65(10), 1325–1329.

33.

Becker, L. A. (2000). Effect size. Accessed on October 12, 2006 from http://web.uccs.edu/lbecker/Psy590/es.htm.

34.

Cohen, J. (1992). A power primer. Psychological Bulletin, 112, 155–159.CrossRef

35.

Kopec, J. A., & Willison, K. D. (2003). A comparative review of four preference-weighted measures of health-related quality of life. Journal of Clinical Epidemiology, 56(4), 317–325.PubMedCrossRef

36.

Marra, C. A., Esdaile, J. M., Guh, D., Kopec, J. A., Brazier, J. E., & Koehler, B. E., et al. (2004). A comparison of four indirect methods of assessing utility values in rheumatoid arthritis. Medical Care, 42(11), 1125–1131.PubMedCrossRef

37.

Brazier, J., Roberts, J., Tsuchiya, A., & Busschbach, J. (2004). A comparison of the EQ-5D and SF-6D across seven patient groups. Health Economics, 13(9), 873–884.PubMedCrossRef

38.

Hays, R. D. (2005). Reliability and validity (including responsiveness). In P. Fayers & R. D. Hays (Eds.), Assessing quality of life in clinical trials (pp. 25–39). New York: Oxford.

39.

Feeny, D., Wu, L., & Eng, K. (2004). Comparing short form 6D, standard gamble, and Health Utilities Index Mark 2 and Mark 3 utility scores: Results from total hip arthroplasty patients. Quality of Life Research, 13(10), 1659–1670.PubMedCrossRef

40.

Ariza-Ariza, R., Hernandez-Cruz, B., Carmona, L., Dolores Ruiz-Montesinos, M., Ballina, J., & Navarro-Sarabia, F. (2006). Assessing utility values in rheumatoid arthritis: A comparison between time trade-off and the EuroQol. Arthritis and Rheumatism, 55(5), 751–756.PubMedCrossRef

41.

Khanna, D., Yan, X., Tashkin, D. P., Furst, D. E., Elashoff, D., Roth, M., et al. (2007). Impact of oral cyclophosphamide on health-related quality of life in patients with active scleroderma lung disease-results from the scleroderma lung study. Arthritis and Rheumatism (in press).

42.

Walters, S. J., & Brazier, J. E. (2005). Comparison of the minimally important difference for two health state utility measures: EQ-5D and SF-6D. Quality of Life Research, 14(6), 1523–1532.PubMedCrossRef

43.

Guyatt, G. H., Feeny, D. H., & Patrick, D. L. (1993). Measuring health-related quality of life. Annals of Internal Medicine, 118(8), 622–629.PubMed

44.

Guyatt, G. H., Norman, G. R., Juniper, E. F., & Griffith, L. E. (2002). A critical look at transition ratings. Journal of Clinical Epidemiology, 55(9), 900–908.PubMedCrossRef

45.

Guyatt, G. H., Osoba, D., Wu, A. W., Wyrwich, K. W., & Norman, G. R. (2002). Methods to explain the clinical significance of health status measures. Mayo Clinic Proceedings, 77(4), 371–383.PubMedCrossRef

46.

Yost, K. J., Sorensen, M. V., Hahn, E. A., Glendenning, G. A., Gnanasakthy, A., & Cella, D. (2005). Using multiple anchor- and distribution-based estimates to evaluate clinically meaningful change on the Functional Assessment of Cancer Therapy-Biologic Response Modifiers (FACT-BRM) instrument. Value Health, 8(2), 117–127.PubMedCrossRef

47.

Tsevat, J., Weeks, J. C., Guadagnoli, E., Tosteson, A. N., Mangione, C. M., & Pliskin, J. S., et al. (1994). Using health-related quality-of-life information: Clinical encounters, clinical trials, and health policy. Journal of General Internal Medicine, 9(10), 576–582.PubMedCrossRef

48.

Patrick, D. L., & Erickson, P. (1993). Health status and health policy : Quality of life in health care evaluation and resource allocation. New York: Oxford University Press.

49.

Drummond, M. (2001). Introducing economic and quality of life measurements into clinical studies. Annals of Medicine, 33(5), 344–349.PubMed

50.

Hays, R. D., & Woolley, J. M. (2000). The concept of clinically meaningful difference in health-related quality-of-life research. How meaningful is it? Pharmacoeconomics, 18(5), 419–423.PubMedCrossRef

51.

Torrance, G. W. (1997). Preferences for health outcomes and cost-utility analysis. The American Journal of Managed Care, 3(Suppl.), S8–S20.PubMed

52.

Revicki, D., & Fairclough, D. L. (2005). Preventing missing data. In P. Fayers & R. D. Hays (Eds.), Assessing quality of life in clinical trials (pp. 167–178). New York: Oxford University Press.

53.

Crosby, R. D., Kolotkin, R. L., & Williams, G. R. (2003). Defining clinically meaningful change in health-related quality of life. Journal of Clinical Epidemiology, 56(5), 395–407.PubMedCrossRef

Titel: Reliability, validity, and minimally important differences of the SF-6D in systemic sclerosis
Auteurs: Dinesh Khanna
Daniel E. Furst
Weng Kee Wong
Joel Tsevat
Philip J. Clements
Grace S. Park
Arnold E. Postlethwaite
Mansoor Ahmed
Shaari Ginsburg
Ron D. Hays
for the Scleroderma Collagen Type 1 Study Group
Publicatiedatum: 01-08-2007
Uitgeverij: Springer Netherlands
Gepubliceerd in: Quality of Life Research / Uitgave 6/2007
Print ISSN: 0962-9343
Elektronisch ISSN: 1573-2649
DOI: https://doi.org/10.1007/s11136-007-9207-3

Andere artikelen Uitgave 6/2007

Maximizing the value of validation findings to better understand treatment satisfaction issues for diabetes

Original Paper

Validity, reliability and clinical relevance of EORTC QLQ-C30 and LC13 in patients with chest malignancies in a palliative setting

A further investigation of health-related quality of life over time among men with HIV infection in the HAART era

Original Paper

Rod O’Connor: Measuring quality of life in health

Book Review

Cultural adaptation and application of the IBS–QOL in China: a disease-specific quality-of-life questionnaire

Effect of trauma on quality of life as mediated by mental distress and moderated by coping and social support among postconflict displaced Ethiopians

Original Paper