Integrating response shift into health-related quality of life research: a theoretical model

s. Outcome research 249 Questionnaire 63,152 Would pick up refer-

Evaluating patient-based outcome measures for use in clinical trials.

The extent to which a doctor or health professional can make a valid assessment of a patient's quality of life, anxiety and depression was investigated in a series of cancer patients. Doctors and patients filled out the same forms, viz. the Karnofsky, Spitzer, Linear Analogue Self Assessment Scales and a series of simple scales designed for this study, at the same time. Correlations between the two sets of scores were poor, suggesting that the doctors could not accurately determine what the patients felt. A further study examining the reproducibility of these scales demonstrated considerable variability in results between different doctors. It is concluded that if a reliable and consistent method of measuring quality of life in cancer patients is required, it must come from the patients themselves and not from their doctors and nurses.

Who should measure quality of life, the doctor or the patient?

This is the first in a series of five articles 

The way we think about health and health care is changing. The two factors driving this change are the recognition of the importance of the social consequences of disease and the acknowledgement that medical interventions aim to increase the length and quality of survival. For these reasons, the quality, effectiveness, and efficiency of health care are often evaluated by their impact on a patient's “quality of life.”

There is no consensus on the definition of quality of life as it is affected by health (health related quality of life). Definitions range from those with a holistic emphasis on the social, emotional, and physical wellbeing of patients after treatment1 to those that describe the impact of a person's health on his or her ability to lead a fulfilling life.2 This article assumes it to be those aspects of an individual's subjective experience that relate both directly and indirectly to health, disease, disability, and impairment. The central concern of this paper is the tendency to regard the quality of life as a constant. We contend that perceptions of health and its meaning vary between individuals and within an individual over time. People assess their health related quality of life by comparing their expectations with their experience. We propose a model of the relation between expectations and experience and use it to illustrate problems in measuring quality of life. The implications of these concepts for the use of quality of life as an indicator of the need for treatment and as an outcome of care are discussed.

#### Summary points

Health related quality of life is the gap between our expectations of health and our experience of it

Perception of quality of life varies between individuals and is dynamic within them

People with different …

https://www.bmj.com/content/bmj/322/7296/1240.full.pdf

Measuring quality of life: Is quality of life determined by expectations or experience?

Methodological approaches for assessing response shift in longitudinal health-related quality-of-life research.

Quality of life is a difficult concept to define and to measure. An hypothesis is proposed which suggests that the quality of life measures the difference, or the gap, at a particular period of time between the hopes and expectations of the individual and that individual's present experiences. Quality of life can only be described by the individual, and must take into account many aspects of life. The approach is goal-orientated, and one of task analysis. The hypothesis is developed in a diagramatic way, and several methods of testing the hypothesis suggested.

https://jme.bmj.com/content/medethics/10/3/124.full.pdf

K C Calman

Papers

Quality of life in cancer patients--an hypothesis.