Assessment Measures and Clinical Scales

  • J. C. Hobart
  • A. J. Thompson


Increasingly, clinical trials in neurology are using standardised scales and assessment measures to determine the effectiveness of therapeutic interventions. To justify this important role in research these measurement methods must demonstrate that they are reliable and valid indicators of abstract and unobservable variables such as disability, mood and health-related quality of life. In this chapter we begin by defining measurement and outlining the advantages of using standardised measurement methods. Then, we explain why it is important to measure variables such as disability and how they can be measured rigorously using Likert scales.


Depression Dementia Interferon Expense Neurol 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Bohrnstedt GW. Measurement. In: Rossi PH, Wright JD, Anderson AB, editors. Handbook of survey research. New York: Academic Press, 1983: 69–121.Google Scholar
  2. 2.
    Nunnally JC Jr. Introduction to psychological measurement. New York: McGraw-Hill, 1970.Google Scholar
  3. 3.
    Peto V, Jenkinson C, Fitzpatrick R, Greenhall R. The development and validation of a short measure of functioning and well-being for individuals with Parkinson’s diseases. Qual Life Res 1995; 4: 241–248.PubMedCrossRefGoogle Scholar
  4. 4.
    Devinsky O. Outcomes research in neurology: incorporating health-related quality of life. Ann Neurol 1995; 37: 141–142.PubMedCrossRefGoogle Scholar
  5. 5.
    Deyo R, Patrick D. Barriers to the use of health status measures in clinical investigation, patient care and policy research. Med Care 1989; 27 (3 Suppl): S254 - S268.PubMedCrossRefGoogle Scholar
  6. 6.
    Du Bois PH. A history of psychological testing. Boston: Allyn and Bacon, 1970.Google Scholar
  7. 7.
    Rogers T. The psychological testing enterprise: an introduction. Pacific Grove, CA: Brooks Cole, 1995.Google Scholar
  8. 8.
    Bland J, Altman D. Cronbach’s alpha. BMJ 1997; 314: 572.PubMedCrossRefGoogle Scholar
  9. 9.
    McIver JP, Carmines EG. Unidimensional scaling. Sage university paper series on quantitative applications in the social sciences, 07–024. Newbury Park, CA: Sage, 1981.Google Scholar
  10. 10.
    Stewart AL, Ware JE Jr, editors. Measuring functioning and well-being: the Medical Outcomes Study approach. Durham, NC: Duke University Press, 1992.Google Scholar
  11. 11.
    Ashworth B. Preliminary trial of carisoprodol in multiple sclerosis. Practitioner 1964; 192: 540–542.PubMedGoogle Scholar
  12. 12.
    Bohannon RW, Smith MB. Inter-rater reliability of a modified Ashworth scale of spasticity. Phys Ther 1987; 67: 206–207.PubMedGoogle Scholar
  13. 13.
    Nunnally JC. Psychometric theory, 2nd ed. New York: McGraw-Hill, 1978.Google Scholar
  14. 14.
    Streiner DL, Norman GR. Health measurement scales: a practical guide to their development and use, 2nd ed. Oxford: Oxford University Press, 1995.Google Scholar
  15. 15.
    Mahoney FI, Barthel DW. Functional evaluation: the Barthel Index. Maryland State Med J 1965; 14: 61–65.Google Scholar
  16. 16.
    Thurstone LL. A law of comparative judgement. Psychol Rev 1927; 34: 273–286.CrossRefGoogle Scholar
  17. 17.
    Guttman L. A basis for scaling qualitative data. Am Sociol Rev 1944; 9: 139–150.CrossRefGoogle Scholar
  18. 18.
    Gulliksen H. Theory of mental tests. New York: Wiley, 1950.CrossRefGoogle Scholar
  19. 19.
    Edwards AL. Techniques of attitude scale construction. New York: Appleton-Century-Crofts, 1957.Google Scholar
  20. 20.
    Torgerson WS. Theory and methods of scaling. New York: Wiley, 1958.Google Scholar
  21. 21.
    Likert RA. A technique for the development of attitudes. Arch Psychol 1932; 140: 5–55.Google Scholar
  22. 22.
    Likert RA, Roslow S, Murphy G. A simple and reliable method of scoring the Thurstone attitude scales. J Soc Psychol 1934; 5: 228–238.CrossRefGoogle Scholar
  23. 23.
    Granger CV, Hamilton BB, Keith RA, Zielezny M, Sherwin FS. Advances in functional assessment for medical rehabilitation. Topics in Geriatric Rehabilitation. Aspen, MD: Rockville, 1986: 59–79.Google Scholar
  24. 24.
    Ware JE Jr. SF-36 Health Survey manual and interpretation guide. Boston, MA: Nimrod Press, 1993.Google Scholar
  25. 25.
    Ware JE Jr, Kosinski MA, Keller SD. SF-36 physical and mental health summary scales: a user’s manual. Boston: The Health Institute, New England Medical Centre, 1994.Google Scholar
  26. 26.
    EuroQol Group. EuroQol: a new facility for the measurement of health-related quality of life. Health Policy 1990; 16: 199–208.Google Scholar
  27. 27.
    Goldberg D. Manual of the General Health Questionnaire. Windsor: NFER-Nelson, 1978.Google Scholar
  28. 28.
    Zigmond AS, Snaith RP. The Hospital Anxiety and Depression Scale. Acta Psychiatr Scand 1983; 67: 361–370.PubMedCrossRefGoogle Scholar
  29. 29.
    Spector PE. Summated rating scale construction: an introduction. Quantitative applications in the social sciences, 07–082. Newbury Park, CA: Sage, 1992.Google Scholar
  30. 30.
    Stevens SS. On the theory of scales of measurement. Science 1946; 103: 677–680.CrossRefGoogle Scholar
  31. 31.
    Merbitz C, Morris J, Grip J. Ordinal scales and foundations of misinference. Arch Phys Med Rehabil 1989; 70: 308–312.PubMedGoogle Scholar
  32. 32.
    Wright BD, Linacre JM. Observations are always ordinal: measurements, however, must be interval. Arch Phys Med Rehabil 1989; 70: 857–860.PubMedGoogle Scholar
  33. 33.
    Guilford JP. Psychometric methods, 2nd ed. New York: McGraw-Hill, 1954.Google Scholar
  34. 34.
    Lord FM. On the statistical treatment of football numbers. Am Psychol 1953; 8: 750–751.CrossRefGoogle Scholar
  35. 35.
    Burke CJ. Additive scales and statistics. Psychol Rev 1953; 60: 73–75.PubMedCrossRefGoogle Scholar
  36. 36.
    Gaito J. Non-parametric methods in psychological research. Psychol Rep 1959; 5: 115–125.Google Scholar
  37. 37.
    Gaito J. Scale classification and statistics. Psychol Bull 1960; 67: 277–278.Google Scholar
  38. 38.
    Baker B, Hardyck C, Petronovich L. Weak measurement vs. strong statistics: an empirical critique of S.S. Stevens proscritions on statistics. Educ Psychol Meas 1966; 26: 291–309.CrossRefGoogle Scholar
  39. 39.
    Gaito J. Measurement scales and statistics: resurgence of an old misconception. Psychol Bull 1980; 87: 564–567.CrossRefGoogle Scholar
  40. 40.
    Gaito J, Yokubynas R. An empirical basis for the statement that measurement scale properties (an meaning) are irrelevant in statistical analyses. Bull Psychon Soc 1986; 24: 449–450.Google Scholar
  41. 41.
    Boneau CA. The effects of violations of assumptions underlying the t-test. Psychol Bull 1960; 57: 49–64.PubMedCrossRefGoogle Scholar
  42. 42.
    Havlicek L, Peterson N. Robustness of the t-test: a guide for researchers on effect of violations of assumptions. Psychol Rep 1974; 34: 1095–1114.CrossRefGoogle Scholar
  43. 43.
    Kenny D, Judd C. Consequences of violating the independence assumptions in analysis of variance. Psychol Bull 1986; 99: 422–431.CrossRefGoogle Scholar
  44. 44.
    Cochran W. Some consequences when the assumptions for the analysis of variance are not satisfied. Biomterics 1947; 3: 22–38.CrossRefGoogle Scholar
  45. 45.
    Havlicek LL, Peterson NL. Effect of the violation of assumptions upon significance levels of the Pearson r. Psychol Bull 1977; 84: 373–377.CrossRefGoogle Scholar
  46. 46.
    Patrick D, Deyo R. Generic and disease-specific measures in assessing health status and quality of life. Med Care 1989; 27 (Suppl): S217 - S232.PubMedCrossRefGoogle Scholar
  47. 47.
    Freeman JA, Langdon DW, Hobart JC, Thompson AJ. Health-related quality of life in people with multiple sclerosis undergoing inpatient rehabilitation. J Neurol Rehabil 1996; 10: 185–194.Google Scholar
  48. 48.
    Kirshner B, Guyatt G. A methodological framework for assessing health indices. J Chron Dis 1985; 38: 27–36.PubMedCrossRefGoogle Scholar
  49. 49.
    Guyatt GH, Krishner B, Jaeschke R. Measuring health status: what are the necessary measurement properties. J Clin Epidemiol 1992; 45: 1341–1345.PubMedCrossRefGoogle Scholar
  50. 50.
    Bowling A. Measuring health: a review of quality of life measurement scales. Buckingham, UK: Open University Press, 1991.Google Scholar
  51. 51.
    Bowling A. Measuring disease: a review of disease-specific quality of life measurement scales. Buckingham, UK: Open University Press, 1995.Google Scholar
  52. 52.
    Herndon RM, editor. Handbook of neurological rating scales. New York: Demos, 1997.Google Scholar
  53. 53.
    McDowell I, Newell C. Measuring health: a guide to rating scales and questionnaires, 2nd ed. Oxford: Oxford University Press, 1996.Google Scholar
  54. 54.
    Wilkin D, Hallam L, Doggett M-A. Measures of need and outcome for primary health care. Oxford: Oxford University Press, 1992.Google Scholar
  55. 55.
    Wade DT. Measurement in neurological rehabilitation. Oxford: Oxford University Press, 1992.Google Scholar
  56. 56.
    Kurtzke JE. Rating neurological impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology 1983; 33: 1444–1452.PubMedCrossRefGoogle Scholar
  57. 57.
    Sprangers MAG, Aaronson NK. The role of health care providers and significant others in evaluating the quality of life of patients with chronic disease: a review. J Clin Epidemiol 1992; 45: 743–760.PubMedCrossRefGoogle Scholar
  58. 58.
    Reiser SJ. The era of the patient. JAMA 1993; 269: 1012–1017.PubMedCrossRefGoogle Scholar
  59. 59.
    Hobart JC, Freeman JA, Lamping DL. Physician and patient oriented outcomes in chronic and progressive neurological disease: which to measure? Curr Opin Neurol 1996; 9: 6.CrossRefGoogle Scholar
  60. 60.
    Rothwell PM, McDowell Z, Wong CK, Dorman PJ. Doctors and patients don’t agree: cross sectional study of patients’ and doctors’ perceptions and assessments of disability in multiple sclerosis. BMJ 1997; 314: 1580–1583.PubMedCrossRefGoogle Scholar
  61. 61.
    Ware JE Jr, Davies-Avery A, Donald C. Conceptualization and measurement of health for adults in the health insurance study, vol V, General health perceptions. Santa Monica, CA: Rand Corporation, 1978.Google Scholar
  62. 62.
    Holmes WC, Bix B, Shea JA. SF-20 score and item distributions in a human immunodeficiency virus-seropositive sample. Med Care 1996; 34: 562–569.PubMedCrossRefGoogle Scholar
  63. 63.
    McHorney CA, Tarlov AR. Individual-patient monitoring in clinical practice: are available health status surveys adequate? Qual Life Res 1995; 4: 293–307.PubMedCrossRefGoogle Scholar
  64. 64.
    Bindman AB, Keane D, Lurie N. Measuring health changes among severely ill patients: the floor phenomenon. Med Care 1990; 28: 1142–1152.PubMedCrossRefGoogle Scholar
  65. 65.
    Baker D, Hays R, Brook R. Understanding changes in health status: is the floor phenomenon merely the last step of the staircase. Med Care 1997; 35: 1–15.PubMedCrossRefGoogle Scholar
  66. 66.
    Fleiss JL. The design and analysis of clinical experiments. New York: Wiley, 1986.Google Scholar
  67. 67.
    Allen MJ, Yen WM. Introduction to measurement theory. Monterey, CA: Brooks Cole, 1979.Google Scholar
  68. 68.
    Lui K. Measurement error and its impact on partial correlation and multiple linear regression analysis. Am J Epidemiol 1988; 127: 864–874.Google Scholar
  69. 69.
    Kupper LL. Effects of the use of unreliable surrogate variables on the validity of epidemiological research. Am J Epidemiol 1984; 120: 643–648.PubMedGoogle Scholar
  70. 70.
    Greenland S. The effect of misclassification in the presence of covariates. Am J Epidemiol 1980; 112: 564–569.PubMedGoogle Scholar
  71. 71.
    Lord FM, Novick MR. Statistical theories of mental test scores. In: Mosteller F, editor. Behavioural science: quantitative methods. Reading, MA: Addison-Wesley, 1968.Google Scholar
  72. 72.
    Nunnally JC, Bernstein IH. Psychometric theory, 3rd ed. New York: McGraw-Hill, 1994.Google Scholar
  73. 73.
    Cronbach U. Essentials of psychological testing, 5th ed. New York: Harper Collins, 1990.Google Scholar
  74. 74.
    Anastasi A, Urbina S. Psychological testing, 7th ed. Upper Saddle River, NJ: Prentice-Hall, 1997.Google Scholar
  75. 75.
    Cronbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika 1951; 16: 297–334.CrossRefGoogle Scholar
  76. 76.
    Shrout PE, Fleiss JL. Intraclass correlations: uses in assessing rater reliability. Psychol Bull 1979; 86: 420–428.PubMedCrossRefGoogle Scholar
  77. 77.
    Cohen J. A coefficient of agreement for nominal scales. Educ Psychol Meas 1960; 20: 37–46.CrossRefGoogle Scholar
  78. 78.
    Ware JE Jr, Johnson S, Davies-Avery A, Brook R. Conceptualization and measurement of health for adults in the health insurance study, vol III, Mental health. Santa Monica, CA, Rand Corporation, 1979.Google Scholar
  79. 79.
    Bravo G, Potvin L. Estimating the reliability of continuous measures with Cronbach’s alpha or the intraclass correlation coefficient: toward the integration of two traditions. J Clin Epidemiol 1991; 44: 381–390.PubMedCrossRefGoogle Scholar
  80. 80.
    Scientific Advisory Committee of the Medical Outcomes Trust. Instrument review criteria. Med Outcomes Trust Bulletin 1995;3:I-IV.Google Scholar
  81. 81.
    Williams JI, Naylor CD. How should health status intruments be assessed? Cautionary notes on procrustean frameworks. J Clin Epidemiol 1992; 45: 1347–1351.PubMedCrossRefGoogle Scholar
  82. 82.
    Cronbach LJ, Meehl PE. Construct validity in psychological tests. Psychol Bull 1955; 52: 281–302.PubMedCrossRefGoogle Scholar
  83. 83.
    Guyatt GH, Walter S, Norman G. Measuring change over time: assessing the usefulness of evaluative instruments. J Chron Dis 1987; 40: 171–178.PubMedCrossRefGoogle Scholar
  84. 84.
    Hays R, Hadorn D. Responsiveness to change: an aspect of validity, not a separate dimension. Qual Life Res 1992; 1: 7373.Google Scholar
  85. 85.
    Guyatt GH, Deyo RA, Charlson M, Levine MN, Mitchell A. Responsiveness and validity in health status measurement: a clarification. J Clin Epidemiol 1989; 42: 403–408.PubMedCrossRefGoogle Scholar
  86. 86.
    Liang MH. Evaluating instrument responsiveness. J Rheumatol 1995; 22: 1191–1192.PubMedGoogle Scholar
  87. 87.
    Cohen J. The earth is round (p 0.05). Am Psychol 1994; 49: 997–1003.CrossRefGoogle Scholar
  88. 88.
    Cortina JM, Dunlap WP. On the logic and purpose of significance testing. Psychol Methods 1997; 2: 161–172.CrossRefGoogle Scholar
  89. 89.
    Kazis LE, Anderson JJ, Meenan RF. Effect sizes for interpreting changes in health status. Med Care 1989; 27(3 Suppl):S178S 189.Google Scholar
  90. 90.
    Cohen J. Statistical power analysis for the behavioural sciences. Hillsdale, NJ: Lawrence Erlbaum, 1988.Google Scholar
  91. 91.
    DeVellis RE Scale development: theory and applications. London: Sage, 1991.Google Scholar
  92. 92.
    Kopec JA, Esdaile JM, Abrahamowicz M, et al. The Quebec Back Pain Disability Scale: measurement properties. Spine 1995; 20: 341–352.PubMedCrossRefGoogle Scholar
  93. 93.
    Ware JE Jr, Harris WJ, Gandek B, Rogers BW, Reese PR. MAPR for Windows: multitrait/multi-item analysis program: — revised user’s guide. Boston, MA: Health Assessment Lab, 1997.Google Scholar
  94. 94.
    Aaronson NK. Quantitative issues in health-related quality of life assessment. Health Policy 1988; 10: 217–230.PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag London 2001

Authors and Affiliations

  • J. C. Hobart
  • A. J. Thompson

There are no affiliations available

Personalised recommendations