Assessment of Quality of Life in Clinical Trials of Cardiovascular Therapies

A number of governments and public policy institutes have developed ldquoQuality of Life Indexesrdquo – statistics that attempt to measure the quality of life for entire states or regions. We develop 14 criteria for determining the validity and usefulness of such QOL indexes to public policy. We then review 22 of the most-used QOL indexes from around the world. We conclude that many of the indexes are successful in that they are reliable, have established time series measures, and can be disaggregated to study subpopulations. However, many fall short in four areas: (1) indexes vary greatly in their coverage and definitions of domains of QOL, (2) none of the indexes distinguish among the concepts of input, throughput, and output that are used by public policy analysts, (3) they fail to show how QOL outputs are sensitive to public policy inputs, and (4) none have examined convergent validity against each other. We conclude that many of these indexes are potentially very useful for public policy and recommend research to further improve them.

Quality of life indexes for national policy: Review and agenda for research

The diagnosis and management of cancer can have a major impact on every aspect of a patient's quality of life. Despite its importance, quality of life is rarely a reported outcome in randomized clinical trials in cancer patients. Failure to collect quality-of-life information may reflect a lack of information among researchers and clinicians about the adequacy and relative merits of measures available for assessing quality of life. We reviewed the adequacy of the 17 existing scales for assessing quality of life in cancer patients against characteristics needed for an adequate measure. None of the existing measures met all of the criteria. Recommendations about the relative adequacy of existing scales were made.

Measuring quality of life in cancer patients.

Although interest is increasing in measurement of quality of life, health status, and functional status in clinical research, most often the primary focus of the research is traditional measures of mortality and morbidity. Quality-of-life assessments are usually added as an afterthought once the design, data collection, and analytic techniques have been specified. When nonmedical outcomes are considered, they are thought of as quality-of-life outcomes. Quality of life is not well conceptualized in the medical and health literature. In addition, clinical researchers are searching for a single best measure of quality of life. Lack of information about clinical significance and sensitivity and uncertainties about the advantages of different administration strategies are impediments to use of developed measures. These issues and problems are discussed and suggestions made about procedures and investigations that could provide guidance.

Quality of life, health status, and clinical research.

This study concerns the quality of life of patients after stroke and how this is influenced by disablement and emotional factors. Ninety-six consecutive patients of mean age 71 years were followed for two years. At the end of that time 23% had experienced a recurrence of stroke and 27% were deceased. Of the survivors 76% were independent as regards activities of daily life (ADL) and lived in their own homes. Age as well as initial function were prognostically important factors. Patients who could participate in interviews marked on a visual analogue scale their evaluation of quality of life before and after stroke. Most of them had experienced a decrease and no improvement was observed during the two years. The deterioration was more pronounced in ADL dependent patients than among the independent. However, depression and anxiety were found to be of similar importance for quality of life as was physical disablement. These findings call for a greater emphasis on psychological support in the care of post stroke patients. The visual analogue scale can be a useful tool for detecting special needs.

Disablement and quality of life after stroke.

The concept “quality of life” is becoming increasingly popular in both the medical and general press. However, from a literature survey of approximately 100 scientific publications in which this concept was used, it appeared that rarely is a definition of this term given. Therefore, it seems useful to formulate several guiding principles: (1) “Quality of life” apparently is too vague a concept. It seems more sensible to isolate a number of relevant factors and to choose the best operational definition possible. The following factors may be considered: daily activity, pattern of complaints, subjective feeling of well-being, and sexual behavior. Based upon these factors one composite score of psychological and social consequences should be developed, analogous to an IQ test. (2) The patient is the sole authority concerning questions on “quality of life.” (3) The concept “quality of life” should indicate more than a person's momentary well being, since this is dependent on mood, physiologic state, accidental events, etc. It is not the situation at one specific point which should be considered but the situation over a certain period. (4) Questions concerning “quality of life” should be put relatively. For example, does a person have more or less complaints during one period as compared to another? A second possibility is to compare a person's answers to those of a carefully chosen control group. It is essential to keep in mind that these psychologic measures are descriptive; they indicate how patients feel during a certain period concerning the above-mentioned areas and are definitely nor normative in the sense of stating what is or is not desirable.

F. S. A. M. van Dam

Papers

Quality of Life: Some Theoretical Issues