Skip to main content
Top
Gepubliceerd in: Quality of Life Research 1/2008

01-02-2008

Comparison of anchor-based and distributional approaches in estimating important difference in common cold

Auteurs: Bruce Barrett, Roger Brown, Marlon Mundt

Gepubliceerd in: Quality of Life Research | Uitgave 1/2008

Log in om toegang te krijgen
share
DELEN

Deel dit onderdeel of sectie (kopieer de link)

  • Optie A:
    Klik op de rechtermuisknop op de link en selecteer de optie “linkadres kopiëren”
  • Optie B:
    Deel de link per e-mail

Abstract

Context

Evaluative health-related quality-of-life instruments used in clinical trials should be able to detect small but important changes in health status. Several approaches to minimal important difference (MID) and responsiveness have been developed.

Objectives

To compare anchor-based and distributional approaches to important difference and responsiveness for the Wisconsin Upper Respiratory Symptom Survey (WURSS), an illness-specific quality of life outcomes instrument.

Design

Participants with community-acquired colds self-reported daily using the WURSS-44. Distribution-based methods calculated standardized effect size (ES) and standard error of measurement (SEM). Anchor-based methods compared daily interval changes to global ratings of change, using: (1) standard MID methods based on correspondence to ratings of “a little better” or “somewhat better,” and (2) two-level multivariate regression models.

Participants

About 150 adults were monitored throughout their colds (1,681 sick days.): 88% were white, 69% were women, and 50% had completed college. The mean age was 35.5 years (SD = 14.7).

Results

WURSS scores increased 2.2 points from the first to second day, and then dropped by an average of 8.2 points per day from days 2 to 7. The SEM averaged 9.1 during these 7 days. Standard methods yielded a between day MID of 22 points. Regression models of MID projected 11.3-point daily changes. Dividing these estimates of small-but-important-difference by pooled SDs yielded coefficients of .425 for standard MID, .218 for regression model, .177 for SEM, and .157 for ES. These imply per-group sample sizes of 870 using ES, 616 for SEM, 302 for regression model, and 89 for standard MID, assuming α = .05, β = .20 (80% power), and two-tailed testing.

Conclusions

Distribution and anchor-based approaches provide somewhat different estimates of small but important difference, which in turn can have substantial impact on trial design.
Literatuur
1.
go back to reference McDowell, I., & Newell, C. (1996). Measuring health: A guide to rating scales and questionnaires. Oxford & New York: Oxford University Press. McDowell, I., & Newell, C. (1996). Measuring health: A guide to rating scales and questionnaires. Oxford & New York: Oxford University Press.
2.
go back to reference Kirshner, B., & Guyatt, G. H. (1985). A methodological framework for assessing health indices. Journal of Chronic Diseases, 38, 27–36.PubMedCrossRef Kirshner, B., & Guyatt, G. H. (1985). A methodological framework for assessing health indices. Journal of Chronic Diseases, 38, 27–36.PubMedCrossRef
3.
go back to reference Jaeschke, R., Singer, J., & Guyatt, G. H. (1989). Measurement of health status: Ascertaining the minimal clinically important difference. Controlled Clinical Trials, 10, 407–415.PubMedCrossRef Jaeschke, R., Singer, J., & Guyatt, G. H. (1989). Measurement of health status: Ascertaining the minimal clinically important difference. Controlled Clinical Trials, 10, 407–415.PubMedCrossRef
4.
go back to reference Powell, C. V., & Kelly, A.-M. (2001). Determining the minimum clinically significant difference in visual analog pain score for children. Annals of Emergency Medicine, 37, 28–31.PubMedCrossRef Powell, C. V., & Kelly, A.-M. (2001). Determining the minimum clinically significant difference in visual analog pain score for children. Annals of Emergency Medicine, 37, 28–31.PubMedCrossRef
5.
go back to reference Redelmeier, D. A., Guyatt, G. H., & Goldstein, R. S. (1996). Assessing the minimal important difference in symptoms: A comparison of two techniques. Journal of Clinical Epidemiology, 49, 1215–1219.PubMedCrossRef Redelmeier, D. A., Guyatt, G. H., & Goldstein, R. S. (1996). Assessing the minimal important difference in symptoms: A comparison of two techniques. Journal of Clinical Epidemiology, 49, 1215–1219.PubMedCrossRef
6.
go back to reference Santanello, N. C., Zhang, J., Seidenberg, B., Reiss, T. F., & Barber, B. L. (1999). What are minimal important changes for asthma measures in a clinical trial? European Respiratory Journal, 14, 23–27.PubMedCrossRef Santanello, N. C., Zhang, J., Seidenberg, B., Reiss, T. F., & Barber, B. L. (1999). What are minimal important changes for asthma measures in a clinical trial? European Respiratory Journal, 14, 23–27.PubMedCrossRef
7.
go back to reference Schunemann, H. J., Griffith, L., Jaeschke, R., Goldstein, R., Stubbing, D., & Guyatt, G. H. (2003). Evaluation of the minimal important difference for the feeling thermometer and the St. George’s Respiratory Questionnaire in patients with chronic airflow obstruction. Journal of Clinical Epidemiology, 56, 1170–1176.PubMedCrossRef Schunemann, H. J., Griffith, L., Jaeschke, R., Goldstein, R., Stubbing, D., & Guyatt, G. H. (2003). Evaluation of the minimal important difference for the feeling thermometer and the St. George’s Respiratory Questionnaire in patients with chronic airflow obstruction. Journal of Clinical Epidemiology, 56, 1170–1176.PubMedCrossRef
8.
go back to reference van Stel, H. F., Maille, A. R., Colland, V. T., & Everaerd, W. (2003). Interpretation of change and longitudinal validity of the quality of life for respiratory illness questionnaire (QoLRIQ) in inpatient pulmonary rehabilitation. Quality of Life Research, 12, 133–145.PubMedCrossRef van Stel, H. F., Maille, A. R., Colland, V. T., & Everaerd, W. (2003). Interpretation of change and longitudinal validity of the quality of life for respiratory illness questionnaire (QoLRIQ) in inpatient pulmonary rehabilitation. Quality of Life Research, 12, 133–145.PubMedCrossRef
9.
go back to reference 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, 717–723.PubMedCrossRef 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, 717–723.PubMedCrossRef
10.
go back to reference Beaton, D. E., Bombardier, C., Katz, J. N., & Wright, J. G. (2001). A taxonomy for responsiveness. Journal of Clinical Epidemiology, 54, 1204–1207.PubMedCrossRef Beaton, D. E., Bombardier, C., Katz, J. N., & Wright, J. G. (2001). A taxonomy for responsiveness. Journal of Clinical Epidemiology, 54, 1204–1207.PubMedCrossRef
11.
go back to reference Brant, R., Sutherland, L., & Hilsden, R. (1999). Examining the minimum important difference. Statistics in Medicine, 18, 2593–2603.PubMedCrossRef Brant, R., Sutherland, L., & Hilsden, R. (1999). Examining the minimum important difference. Statistics in Medicine, 18, 2593–2603.PubMedCrossRef
12.
go back to reference Deyo, R. A., & Centor, R. M. (1986). Assessing the responsiveness of functional scales to clinical change: An analogy to diagnostic test performance. Journal of Chronic Diseases, 39, 897–906.PubMedCrossRef Deyo, R. A., & Centor, R. M. (1986). Assessing the responsiveness of functional scales to clinical change: An analogy to diagnostic test performance. Journal of Chronic Diseases, 39, 897–906.PubMedCrossRef
13.
go back to reference Frost, M. H., Bonomi, A. E., Ferrans, C. E., Wong, G. Y., & Hays, R. D. (2002). Clinical Significance Consensus Meeting Group. Patient, clinician, and population perspectives on determining the clinical significance of quality-of-life scores. Mayo Clinic Proceedings, 77, 488–494.PubMedCrossRef Frost, M. H., Bonomi, A. E., Ferrans, C. E., Wong, G. Y., & Hays, R. D. (2002). Clinical Significance Consensus Meeting Group. Patient, clinician, and population perspectives on determining the clinical significance of quality-of-life scores. Mayo Clinic Proceedings, 77, 488–494.PubMedCrossRef
14.
go back to reference Guyatt, G. H., Osoba, D., Wu, A. W., Wyrwich, K. W., & Norman, G. R. (2002). Clinical Significance Consensus Meeting Group. Methods to explain the clinical significance of health status measures. Mayo Clinic Proceedings, 77, 371–383.PubMed Guyatt, G. H., Osoba, D., Wu, A. W., Wyrwich, K. W., & Norman, G. R. (2002). Clinical Significance Consensus Meeting Group. Methods to explain the clinical significance of health status measures. Mayo Clinic Proceedings, 77, 371–383.PubMed
15.
go back to reference Norman, G. R., Stratford, P., & Regehr, G. (1997). Methodological problems in the retrospective computation of responsiveness to change: The lesson of Cronbach. Journal of Clinical Epidemiology, 50, 869–879.PubMedCrossRef Norman, G. R., Stratford, P., & Regehr, G. (1997). Methodological problems in the retrospective computation of responsiveness to change: The lesson of Cronbach. Journal of Clinical Epidemiology, 50, 869–879.PubMedCrossRef
16.
go back to reference Norman, G. R., Sridhar, F. G., Guyatt, G. H., & Walter, S. D. (2001). Relation of distribution- and anchor-based approaches in interpretation of changes in health-related quality of life. Medical Care, 39, 1039–1047.PubMedCrossRef Norman, G. R., Sridhar, F. G., Guyatt, G. H., & Walter, S. D. (2001). Relation of distribution- and anchor-based approaches in interpretation of changes in health-related quality of life. Medical Care, 39, 1039–1047.PubMedCrossRef
17.
go back to reference Samsa, G. (2001). How should the minimum important difference for a health-related quality-of-life instrument be estimated? Medical Care, 39, 1037–1038.PubMedCrossRef Samsa, G. (2001). How should the minimum important difference for a health-related quality-of-life instrument be estimated? Medical Care, 39, 1037–1038.PubMedCrossRef
18.
go back to reference Husted, J. A., Gladman, D. D., Cook, R. J., & Farewell, V. T. (1998). Responsiveness of health status instruments to changes in articular status and perceived health in patients with psoriatic arthritis. Journal of Rheumatology, 25, 2146–2155.PubMed Husted, J. A., Gladman, D. D., Cook, R. J., & Farewell, V. T. (1998). Responsiveness of health status instruments to changes in articular status and perceived health in patients with psoriatic arthritis. Journal of Rheumatology, 25, 2146–2155.PubMed
19.
go back to reference Guyatt, G. H., Walter, S., & Norman, G. (1987). Measuring change over time: Assessing the usefulness of evaluative instruments. Journal of Chronic Diseases, 40, 171–178.PubMedCrossRef Guyatt, G. H., Walter, S., & Norman, G. (1987). Measuring change over time: Assessing the usefulness of evaluative instruments. Journal of Chronic Diseases, 40, 171–178.PubMedCrossRef
20.
go back to reference Juniper, E. F., & .Guyatt, G. H. (1991). Development and testing of a new measure of health status for clinical trials in rhinoconjunctivitis. Clinical & Experimental Allergy, 21, 77–83.CrossRef Juniper, E. F., & .Guyatt, G. H. (1991). Development and testing of a new measure of health status for clinical trials in rhinoconjunctivitis. Clinical & Experimental Allergy, 21, 77–83.CrossRef
21.
go back to reference Juniper, E. F., Guyatt, G. H., Willan, A., & Griffith, L. E. (1994). Determining a minimal important change in a disease-specific Quality of Life Questionnaire. Journal of Clinical Epidemiology, 47, 81–87.PubMedCrossRef Juniper, E. F., Guyatt, G. H., Willan, A., & Griffith, L. E. (1994). Determining a minimal important change in a disease-specific Quality of Life Questionnaire. Journal of Clinical Epidemiology, 47, 81–87.PubMedCrossRef
22.
go back to reference 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, 557–560.PubMed 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, 557–560.PubMed
23.
go back to reference Todd, K. H., & Funk, J. P. (1996). The minimum clinically important difference in physician-assigned visual analog pain scores. Academic Emergency Medicine, 3, 142–146.PubMed Todd, K. H., & Funk, J. P. (1996). The minimum clinically important difference in physician-assigned visual analog pain scores. Academic Emergency Medicine, 3, 142–146.PubMed
24.
go back to reference Bruynesteyn, K., van der Heijde, H. D., Boers, M., Lassere, M., Boonen, A., Edmonds, J, et al. (2001). Minimal clinically important difference in radiological progression of joint damage over 1 year in rheumatoid arthritis: Preliminary results of a validation study with clinical experts. Journal of Rheumatology, 28, 904–910.PubMed Bruynesteyn, K., van der Heijde, H. D., Boers, M., Lassere, M., Boonen, A., Edmonds, J, et al. (2001). Minimal clinically important difference in radiological progression of joint damage over 1 year in rheumatoid arthritis: Preliminary results of a validation study with clinical experts. Journal of Rheumatology, 28, 904–910.PubMed
25.
go back to reference Bombardier, C., Hayden, J., & Beaton, D. E. (2001). Minimal clinically important difference, low back pain: Outcomes measures. Journal of Rheumatology, 28, 431–438.PubMed Bombardier, C., Hayden, J., & Beaton, D. E. (2001). Minimal clinically important difference, low back pain: Outcomes measures. Journal of Rheumatology, 28, 431–438.PubMed
26.
go back to reference Farrar, J. T., Portenoy, R. K., Berlin, J. A., Kinman, J. L., & Strom, B. L. (2000). Defining the clinically important difference in pain outcome measures. Pain, 88, 287–294.PubMedCrossRef Farrar, J. T., Portenoy, R. K., Berlin, J. A., Kinman, J. L., & Strom, B. L. (2000). Defining the clinically important difference in pain outcome measures. Pain, 88, 287–294.PubMedCrossRef
27.
go back to reference Kazis, L. E., Anderson, J. L., Meenan, R. F. (1989). Effect sizes for interpreting changes in health status. Medical Care, 27(Suppl), S178–S189.PubMedCrossRef Kazis, L. E., Anderson, J. L., Meenan, R. F. (1989). Effect sizes for interpreting changes in health status. Medical Care, 27(Suppl), S178–S189.PubMedCrossRef
28.
go back to reference Ward, M. M., Marx, A. S., & Barry, N. N. (2000). Identification of clinically important changes in health status using receiver operating characteristic curves. Journal of Clinical Epidemiology, 53, 279–284.PubMedCrossRef Ward, M. M., Marx, A. S., & Barry, N. N. (2000). Identification of clinically important changes in health status using receiver operating characteristic curves. Journal of Clinical Epidemiology, 53, 279–284.PubMedCrossRef
29.
go back to reference Wyrwich, K. W., Tierney, W. M., & Wolinsky, F. D. (2002). Using the standard error of measurement to identify important changes on the Asthma Quality of Life Questionnaire. Quality of Life Research, 11, 1–7.PubMedCrossRef Wyrwich, K. W., Tierney, W. M., & Wolinsky, F. D. (2002). Using the standard error of measurement to identify important changes on the Asthma Quality of Life Questionnaire. Quality of Life Research, 11, 1–7.PubMedCrossRef
30.
go back to reference Cohen, J. (1988) Statistical power analysis for the behavioral sciences. Hillsdale, N.J.: Lawrence Erlbaum Associates. Cohen, J. (1988) Statistical power analysis for the behavioral sciences. Hillsdale, N.J.: Lawrence Erlbaum Associates.
31.
go back to reference Norman, G. R., Wyrwich, K. W., & Patrick, D. L. (2007). The mathematical relationship among different forms of responsiveness coefficients. Quality of Life Research, 16(5), 815–822.PubMedCrossRef Norman, G. R., Wyrwich, K. W., & Patrick, D. L. (2007). The mathematical relationship among different forms of responsiveness coefficients. Quality of Life Research, 16(5), 815–822.PubMedCrossRef
32.
go back to reference Wyrwich, K. W., Nienaber, N. A., Tierney, W. M., & Wolinsky, F. D. (1999). Linking clinical relevance and statistical significance in evaluating intra-individual changes in health-related quality of life. Medical Care, 37, 469–478.PubMedCrossRef Wyrwich, K. W., Nienaber, N. A., Tierney, W. M., & Wolinsky, F. D. (1999). Linking clinical relevance and statistical significance in evaluating intra-individual changes in health-related quality of life. Medical Care, 37, 469–478.PubMedCrossRef
33.
go back to reference Wyrwich, K. W. (2004). Minimal important difference thresholds and the standard error of measurement: Is there a connection? Journal of Biopharmaceutical Statistics, 14, 97–110.PubMedCrossRef Wyrwich, K. W. (2004). Minimal important difference thresholds and the standard error of measurement: Is there a connection? Journal of Biopharmaceutical Statistics, 14, 97–110.PubMedCrossRef
34.
go back to reference Barrett, B., Locken, K., Maberry, R., Schwamman, J., Bobula, J., Brown, R., et al. (2002). The Wisconsin Upper Respiratory Symptom Survey: Development of an instrument to measure the common cold. Journal of Family Practice, 51, 265–273.PubMed Barrett, B., Locken, K., Maberry, R., Schwamman, J., Bobula, J., Brown, R., et al. (2002). The Wisconsin Upper Respiratory Symptom Survey: Development of an instrument to measure the common cold. Journal of Family Practice, 51, 265–273.PubMed
35.
go back to reference Barrett, B. P., Brown, R. L., Locken, K., Maberry, R., Bobula, J. A., & D’Alessio, D. (2002). Treatment of the common cold with unrefined echinacea: A randomized, double-blind, placebo-controlled trial. Annals of Internal Medicine, 137, 939–946.PubMed Barrett, B. P., Brown, R. L., Locken, K., Maberry, R., Bobula, J. A., & D’Alessio, D. (2002). Treatment of the common cold with unrefined echinacea: A randomized, double-blind, placebo-controlled trial. Annals of Internal Medicine, 137, 939–946.PubMed
36.
go back to reference Barrett, B., Brown, R., Mundt, M., Safdar, N., Dye, L., Maberry, R., et al. (2005). The Wisconsin Upper Respiratory Symptom Survey is responsive, reliable, and valid. Journal of Clinical Epidemiology, 58, 609–617.PubMedCrossRef Barrett, B., Brown, R., Mundt, M., Safdar, N., Dye, L., Maberry, R., et al. (2005). The Wisconsin Upper Respiratory Symptom Survey is responsive, reliable, and valid. Journal of Clinical Epidemiology, 58, 609–617.PubMedCrossRef
37.
go back to reference Jackson, G. G., Dowling, H. F., & Muldoon, R. L. (1962). Present concepts of the common cold. American Journal of Public Health, 52, 940–945.PubMed Jackson, G. G., Dowling, H. F., & Muldoon, R. L. (1962). Present concepts of the common cold. American Journal of Public Health, 52, 940–945.PubMed
38.
go back to reference McHorney, C. A., Ware, J. E., & Raczek, A. E. (1998). The MOS 36-item short-form health survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Medical Care, 31, 247–263.CrossRef McHorney, C. A., Ware, J. E., & Raczek, A. E. (1998). The MOS 36-item short-form health survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Medical Care, 31, 247–263.CrossRef
39.
go back to reference Ware, J. E, Kosinski, M., Dewey, J. E., & Gandek, B. (2001) How to score and interpret single-item health status measures: A manual for users of the SF-8 health survey. Lincoln RI: Quality Metric. Ware, J. E, Kosinski, M., Dewey, J. E., & Gandek, B. (2001) How to score and interpret single-item health status measures: A manual for users of the SF-8 health survey. Lincoln RI: Quality Metric.
40.
go back to reference Barrett, B., Brown, R., Voland, R., Maberry, R., & Turner, R. (2006). Relations among questionnaire and laboratory measures of rhinovirus infection. European Respiratory Journal, 28, 358–363.PubMedCrossRef Barrett, B., Brown, R., Voland, R., Maberry, R., & Turner, R. (2006). Relations among questionnaire and laboratory measures of rhinovirus infection. European Respiratory Journal, 28, 358–363.PubMedCrossRef
41.
go back to reference Yang, M., & Goldstein, H. (1996). Multilebel models for longitudinal data. In U. Engel & J. Tanner (Eds.), Analysis of change: Advanced techniques in panel data analysis (pp. 191–220). Berlin: Walter de Gruyter. Yang, M., & Goldstein, H. (1996). Multilebel models for longitudinal data. In U. Engel & J. Tanner (Eds.), Analysis of change: Advanced techniques in panel data analysis (pp. 191–220). Berlin: Walter de Gruyter.
42.
go back to reference Jaeschke, R., Singer, J., & Guyatt, G. H. (1990). A comparison of seven-point and visual analogue scales. Data from a randomized trial. Controlled Clinical Trials, 11, 43–51.PubMedCrossRef Jaeschke, R., Singer, J., & Guyatt, G. H. (1990). A comparison of seven-point and visual analogue scales. Data from a randomized trial. Controlled Clinical Trials, 11, 43–51.PubMedCrossRef
43.
go back to reference Miller, G. A. (1956). The magical number seven plus or minus two: some limits on our capacity for processing information. Psychological Review, 63, 81–97.PubMedCrossRef Miller, G. A. (1956). The magical number seven plus or minus two: some limits on our capacity for processing information. Psychological Review, 63, 81–97.PubMedCrossRef
44.
go back to reference Froberg, D. G., & Kane, R. L. (1989). Methodology for measuring health-state preferences-II: Scaling methods. Journal of Clinical Epidemiology, 42, 459–471.PubMedCrossRef Froberg, D. G., & Kane, R. L. (1989). Methodology for measuring health-state preferences-II: Scaling methods. Journal of Clinical Epidemiology, 42, 459–471.PubMedCrossRef
45.
go back to reference Cohen, J. (1969). Statistical power analysis for the behavioural sciences. London: Academic Press. Cohen, J. (1969). Statistical power analysis for the behavioural sciences. London: Academic Press.
46.
go back to reference Gwaltney, J. M Jr., Hendley, J. O., & Patrie, J. T. (2003). Symptom severity patterns in experimental common colds and their usefulness in timing onset of illness in natural colds. Clinical Infectious Diseases, 36, 714–723.PubMedCrossRef Gwaltney, J. M Jr., Hendley, J. O., & Patrie, J. T. (2003). Symptom severity patterns in experimental common colds and their usefulness in timing onset of illness in natural colds. Clinical Infectious Diseases, 36, 714–723.PubMedCrossRef
47.
go back to reference Cronbach, L. J. (1957). The two disciplines of scientific psychology. American Psychologist, 12, 671–684.CrossRef Cronbach, L. J. (1957). The two disciplines of scientific psychology. American Psychologist, 12, 671–684.CrossRef
48.
go back to reference Gleser, G. C., Cronbach, L. J., & Rajaratnam, N. (1965). Generalizability of scores influenced by multiple sources of variance. Psychometrika, 30, 395–418.PubMedCrossRef Gleser, G. C., Cronbach, L. J., & Rajaratnam, N. (1965). Generalizability of scores influenced by multiple sources of variance. Psychometrika, 30, 395–418.PubMedCrossRef
49.
go back to reference Cronbach, L. J., & Furby, L. (1970). How should we measure “change” – Or should we? Psychological Bulletin, 74, 68–80.CrossRef Cronbach, L. J., & Furby, L. (1970). How should we measure “change” – Or should we? Psychological Bulletin, 74, 68–80.CrossRef
50.
go back to reference Deyo, R. A., & Inui, T. S. (1984). Toward clinical applications of health status measures: sensitivity of scales to clinically important changes. Health Services Research, 19, 277–289. Deyo, R. A., & Inui, T. S. (1984). Toward clinical applications of health status measures: sensitivity of scales to clinically important changes. Health Services Research, 19, 277–289.
51.
go back to reference Ross, M. (1989). Relation of implicit theories to the construction of personal histories. Psychological Review, 96, 341–347.CrossRef Ross, M. (1989). Relation of implicit theories to the construction of personal histories. Psychological Review, 96, 341–347.CrossRef
52.
go back to reference Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211, 453–458.PubMedCrossRef Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211, 453–458.PubMedCrossRef
53.
go back to reference Norman, G. R., Sloan, J. A., & Wyrwich, K. W. (2003). Interpretation of changes in health-related quality of life: The remarkable universality of half a standard deviation. Medical Care, 41, 582–592.PubMedCrossRef Norman, G. R., Sloan, J. A., & Wyrwich, K. W. (2003). Interpretation of changes in health-related quality of life: The remarkable universality of half a standard deviation. Medical Care, 41, 582–592.PubMedCrossRef
54.
go back to reference Norman, G. R. (2005). The relation between the minimally important difference and patient benefit. COPD, 2, 69–73.PubMedCrossRef Norman, G. R. (2005). The relation between the minimally important difference and patient benefit. COPD, 2, 69–73.PubMedCrossRef
55.
go back to reference Llewellyn-Thomas, H. A., Williams, J. I., Levy, L., & Naylor, C. D. (1996). Using a trade-off technique to assess patients’ treatment preferences for benign prostatic hyperplasia. Medical Decision Making, 16, 262–282.PubMedCrossRef Llewellyn-Thomas, H. A., Williams, J. I., Levy, L., & Naylor, C. D. (1996). Using a trade-off technique to assess patients’ treatment preferences for benign prostatic hyperplasia. Medical Decision Making, 16, 262–282.PubMedCrossRef
56.
go back to reference Naylor, C. D., & Llewellyn-Thomas, H. A. (1994). Can there be a more patient-centred approach to determining clinically important effect sizes for randomized treatment trials? Journal of Clinical Epidemiology, 47, 787–795.PubMedCrossRef Naylor, C. D., & Llewellyn-Thomas, H. A. (1994). Can there be a more patient-centred approach to determining clinically important effect sizes for randomized treatment trials? Journal of Clinical Epidemiology, 47, 787–795.PubMedCrossRef
Metagegevens
Titel
Comparison of anchor-based and distributional approaches in estimating important difference in common cold
Auteurs
Bruce Barrett
Roger Brown
Marlon Mundt
Publicatiedatum
01-02-2008
Uitgeverij
Springer Netherlands
Gepubliceerd in
Quality of Life Research / Uitgave 1/2008
Print ISSN: 0962-9343
Elektronisch ISSN: 1573-2649
DOI
https://doi.org/10.1007/s11136-007-9277-2

Andere artikelen Uitgave 1/2008

Quality of Life Research 1/2008 Naar de uitgave