BioPsychoSocial Assessment Tools for the Elderly - Assessment Summary Sheet
Test: Quality of Well-being (QWB) Scale
Year: 1973; Revised 1976, 1994
Domain: Biological, Social
Assessment Tool Category: Quality of Life
Variations/Translations: Formerly the Health Status Index, Index of Well-being. An alternate version of the index with a simplified scoring procedure exists called the Function Status Index (FSI) (McDowell & Newell, 1996). The QWB Scale has been translated into various languages, including a number of Indo-Chinese languages such as Mandarin, Cantonese, Hmong, Khmer, and Vietnamese.
Method of Delivery: Clinical interview
Description: The QWB Scale is designed to measure quality of life through determining the objective levels of an individual’s functioning in three domains: mobility, physical activity, and social activity. In addition to these three domains, the QWB Scale also assesses a wide variety of symptoms. The QWB Scale measures functional performance rather than functional ability: the subject is asked to report activity that has actually been performed, as opposed to activity that the subject thinks that they could hypothetically perform (Anderson, Kaplan, Berry, Bush, & Rumbaut, 1989). The QWB Scale is a good measure of outcomes of serious illness over time (Bowling, 2005).
Scoring/Interpretation: Each of the three domain scales is weighted. Overall scores range from 0 to 1.0 with a higher score representing a better state of health. A score of zero indicates death while a score of 1.0 indicates asymptomatic optimum functioning (Kaplan et al., 1989). Scoring does allow a score of less than zero, indicating a state worse than death (e.g. prolonged vegetative state) (McDowell & Newell, 1996).
Time to Administer: 20 minutes (McDowell & Newell, 1996)
Availability: Interview Schedule and Manual available from R. Kaplan at the School of Medicine, University of California.
Validity (Quantitative): Due to the broad scope of the QWB, and the fact that it takes mortality, symptoms, and problems as well as functional levels into account, content validity of the instrument is deemed to be acceptable. Correlations between the QWB Scale and subjective and objective measures of health have been tested. The QWB Scale has a correlation of r = -0.75 with the number of reported symptoms in a patient group and of r = -0.96 with the number of chronic health problems reported. In patients with cystic fibrosis, results from pulmonary function tests have been compared to QWB results, with a correlation of r = 0.55 for FEV1 and r = 0.58 for VO2max. In chronic obstructive pulmonary disease patients, r = 0.51 for FEV1 and 0.41 for an exercise tolerance test. The QWB has been compared to other scales; correlations with Jette’s Functional Status Index and the Sickness Impact Profile were good (r = 0.46 and -0.55, respectively) (McDowell, 2006).
Reliability (Quantitative): Reliability of scale weighting found to be high (0.90) (McDowell & Newell, 1996). Test-retest reliability has been reported in two studies as being high (0.93 and 0.98). Internal consistency estimates from four populations have been reported and all have exceeded 0.90 (Bowling, 2005).
Anderson, J.P., Kaplan, R.M., Berry, C.C., Bush, J.W., & Rumbaut, R.G. (1989). Interday reliability of function assessment for a health status measure: The Quality of Well-being Scale. Medical Care, 27(11), 1076-1084.
Bowling, A. (2005). Measuring Health: A review of quality of life measurement scales (3rd ed.). New York, NY: Open University Press.
Kaplan, R.M., Anderson, J.P., Wu, A.W., Mathews, W.C., Kozin, F., & Orenstein, D. (1989). The Quality of Well-being Scale: Applications in AIDS, cystic fibrosis, and arthritis. Medical Care, 27(3), S27-S43.
McDowell, I., & Newell, C. (1996). Measuring Health: A Guide to Rating Scales and Questionnaires (2nd ed). New York: Oxford University Press.