A taxonomy of the uses of health-related quality-of-life instruments in cancer care and the clinical meaningfulness of the results.
OBJECTIVE
To propose a taxonomy of psychometrically based, health-related quality-of-life instruments related to three levels of decision-making of health care: the macro, meso and micro levels. The choice of appropriate health-related quality-of-life instruments for each level of desired decision making in various clinical settings is illustrated. A secondary objective was to describe solutions for some of the difficulties inherent in the interpretation of the results of health-related quality-of-life assessment.


METHODS
The three main levels of clinical decision making are listed and the instruments used most frequently in cancer clinical trials are reviewed from the medical literature.


METHODS
Generic and utility-based instruments are likely to be the most valuable at the macro level of decision making, whereas condition-specific, disease-specific, and situation-specific instruments are most useful for decision making at the meso and micro levels. A determination of the proportions of patients who have reached a meaningful change in health-related quality-of-life scores (eg, > or =10 for scales of 1-100) over a standard period is a rational approach to interpreting the significance of changes in scores.


CONCLUSIONS
Awareness of the level of decision making that is involved in the clinical assessment of health-related quality of life can be helpful in choosing instruments that are appropriate for various clinical settings. Some of the difficulties in interpreting the meaning of changes in health-related quality-of-life scores can be overcome by comparing the proportions of patients who have achieved a preset magnitude of change.
Osoba
David
D
QOL Consulting, Vancouver, British Columbia, Canada. david_osoba@telus.net
D002170:Canada; D002965:Classification; D003657:Decision Making; D006302:Health Services Research; D006801:Humans; D009369:Neoplasms / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D018434:Sickness Impact Profile