Can quality or quality-of-life be defined?

The aim of this paper is to examine the oft-heard concern that quality or quality-of-life cannot be defined. This concern persists today, even in the presence of countless studies that claim to be assessing quality or quality-of-life. There is obviously a disconnect here that warrants some attention, if not explanation. In this study, I summarize the extent of this disconnect and offer a number of potential explanations of why this situation exists. I review the role that operational definitions, statistical and empirical models, and content-specific definitions play in defining quality and/or quality-of-life. I conclude that none of these approaches provide a comprehensive definition of quality or quality-of-life. In its stead, I will argue that quality or quality-of-life represents a distinctive pattern of thinking. I establish this pattern by examining the cognitive-linguistic basis of these definitions and argue that when this is done it will be possible to identify an universal cognitive (hybrid) construct that describes how a person thinks about all types of qualitative assessments. The implication of this is that for a study to claim that it is defining or assessing quality or quality-of-life, it will first have to demonstrate the presence of the elements of this hybrid construct.

Why perform a quality or quality-of-life assessment?

The purpose of this article is to prompt quality-of-life researchers to periodically ask themselves why they are doing what they are doing. I will give you my answer to this question, but also briefly review the historic events that lead to the development of the field. Examining this history should teach each of us that the field evolved from the application of a operations research perspective to the medical care system. As such, more attention should be given to the quality control potential of quality-of-life assessments. I suggest two approaches to this quality control task; the prevention of adverse events and the enhancement of the qualitative status of ill persons.

Weight loss and health-related quality of life: results at 1-year follow-up.

To evaluate the 1-year results of treatment-induced weight loss on health-related quality of life (HRQL), 32 mildly to moderately overweight persons who participated in a 13-week weight loss program completed the Medical Outcomes Study Short Form-36 Health Survey (SF-36) at baseline, immediately after the program, and at 1-year follow-up. At 1 year, 65.6% of participants maintained at least some weight loss. The improvements on HRQL observed immediately after treatment on the physical functioning, role-physical, general health, vitality, and mental health scales of the SF-36 were maintained only on the general health and vitality scales at 1 year. There were no significant differences between weight maintainers and weight regainers on change from baseline to 1-year follow-up on HRQL. Our findings suggest that treatment-induced weight loss among mildly to moderately overweight persons improves HRQL and that at least some of these benefits are maintained at 1-year follow-up regardless of whether the weight loss is maintained.

Patients' rights, quality of life, and health care system performance.

The purpose of this paper is to promote the development of a social contract between patient and clinician that permits patients to state how they want to live as they survive rather than what they are willing to lose to extend their survival. To do this, patients must have sufficient leverage to affect the nature of the care they receive. This leverage, it is proposed, can be achieved by first making a 'Declaration of Patients' Rights Relative to Their Quality of Life' and then evaluating the extent to which the patient's providers comply with this rights statement. The paper also reviews The World Health Report 2000 [Health Systems: Improving Performance Geneva: WHO, 2000] as an example of an alternative approach to defining a health care social contract and evaluating a health system's performance. Also discussed, were steps that could be taken to facilitate the integration of the patients' rights statement into medical practice and health care systems performance.

Cognitive approaches to summary measurement: its application to the measurement of diversity in health-related quality of life assessments.

This paper describes elements of a cognitive approach to summary measurement, as it is applied to health-related quality of life (HRQOL) assessment. A summary measure, by its very nature, represents, but does not reproduce, some body of information. As a consequence, how a summary measure is formulated becomes a critical determinant of its usefulness. In most cases, formal (arithmetic or investigator-based) methods are used. However, it was also noted that a person ordinarily summarizes the information they receive. Qualitative analytic techniques (e.g., cognitive interviewing methods) can provide insight into the cognitive processes underlying such summary formation. These cognitive processes, formulated as algorithms, would also be expected to vary as a function of different groups of respondents and settings. Finding a common denominator, a common algorithm, would provide a consensus summary measure amongst diverse groups whose HRQOL is being assessed.

Women's angiographic vitamin and estrogen trial: design and methods.

The Women's Angiographic Vitamin and Estrogen trial was a randomized, double-blind, placebo-controlled study designed to test the efficacy of estrogen replacement and antioxidant vitamins for preventing angiographic progression of coronary artery disease. Postmenopausal women with one or more angiographically documented coronary stenoses of 15-75% at baseline were assigned in a 2 x 2 factorial randomization to active hormone replacement therapy (conjugated estrogens for women who had had a hysterectomy or conjugated estrogens with medroxyprogesterone for women with intact uteri) or placebo and to active vitamins E and C or their placebos. Seven clinical centers, five in the United States and two in Canada, randomized 423 women between July 1997 and July 1999. Quantitative coronary angiography was performed at baseline and repeated after projected mean follow-up of 3 years.

Group vs individual approaches to understanding the clinical significance of differences or changes in quality of life.

This article focuses on the traversing of group and individual levels of quality-of-life data. A deductive approach is used to address the extent to which group data can be used to estimate clinical significance at the individual level. An inductive approach is used to evaluate the extent to which individual change data can be brought to the group level to define clinical significance. Both approaches have benefits and drawbacks. This article addresses how clinical significance can be defined for an individual when the threshold for meaningfulness is drawn from group data. It also addresses the condition under which one can use the same threshold difference for group vs individual differences or changes. A sample inductive approach explores the means to identify a clinically significant result or change, with use of insights from cognitive psychology. In most deductive approaches, the identification of a clinically significant difference or change requires identification of a criterion (or at least an interpretable anchor) against which the significance of a change in respondent score is compared.