Quality of Life
QUALITY OF LIFE
Although the concept of quality of life (QL) is not new, quality of life as an area of research and scholarship dates back only to the 1960s. Schuessler and Fisher (1985) noted that President Dwight Eisenhower's 1960 Commission on National Goals and Bauer's book on social indicators (1966) are often credited as providing the impetus for the development of QL as an area of research. Campbell (1981) suggested that the 1960s were favorable times for the development of QL research because of the emergence then of a belief that people must examine the quality of their lives and must do so in an environment that goes beyond providing material goods to foster individual happiness. Campbell quotes President Lyndon Johnson, who stated in 1964:
The task of the Great Society is to ensure our people the environment, the capacities, and the social structures which will give them a meaningful chance to pursue their individual happiness. Thus the Great Society is concerned not with how much, but with how good—not with the quantity of goods but with the quality of their lives. (Campbell 1981, p. 4)
Schuessler and Fisher (1985) note that the Russell Sage Foundation promoted QL and research on social indicators in the 1960s and 1970s and that the Institute for Social Research at the University of Michigan and the National Opinion Research Center at the University of Chicago have conducted QL research since the late 1960s. Despite the high volume of QL research during the 1960s and 1970s, it was not until 1979 that "quality of life" became an index entry in Sociological Abstracts.
The emerging QL research in the 1970s provided a departure from previous work that focused on objective indicators, primarily economic in nature, of individual well-being. The book The Quality of American Life: Perceptions, Evaluations, and Satisfactions, published by Campbell and colleagues in 1976, particularly promoted the use of subjective or psychological indicators of well-being. The work reported was founded on the conviction that the relationship between objective and subjective well-being indicators was weak and poorly understood. Moreover, the rising affluence of the post–World War II era had been accompanied by steady increases in social problems afflicting American society as well as other Western societies.
The year 1976 also saw the publication of another major work focusing on subjective indicators of well-being. Social Indicators of Well-Being: Americans' Perceptions of Life Quality by Andrews and Withy (1976) reported findings from interviews with representative samples of more than 5,000 Americans. The interviews focused on satisfaction with the quality of various life domains. A more recent volume, titled Research on the Quality of Life and edited by Frank Andrews (1986), brought together a variety of papers originating at a symposium honoring the memory of Angus Campbell, one of the founders of the Institute for Social Research. Although this volume included important papers on cross-national differences in life satisfaction and papers on African-Americans and Hispanics, a number of the papers had no direct relationship to QL research. Rockwell (1989) noted that a useful focus of the field was lost in this volume, the focus on subjective indicators of the quality of life. Andrews also noted that support for large-scale, wide-ranging surveys had become increasingly difficult in the 1980s in the United States, resulting in a lack of replication of the national surveys conducted in the previous decade by the Institute for Social Research.
Parallel to the large national surveys of subjective well-being during the 1970s, there was a proliferation of studies focusing on the subjective well-being of the elderly. In a useful article, Larson (1978) reviewed three decades of research that focused on the psychological well-being of older people. Perhaps no other area of research in the emerging field of gerontology had received as much attention during the 1960s and 1970s as the area of life satisfaction, morale, mental health, and psychological well-being in general. Much of this research was spurred by the lively debate over the merits of disengagement theory (proposed by Cumming and Henry 1961) and activity theory (identified with various authors, including Havighurst et al. 1968; Maddox 1968, 1970) in predicting "successful aging." Gerontological work in the 1980s showed a marked decline in the number of articles predicting life satisfaction and morale and an increase in articles focusing on specific dimensions of psychological well-being, such as depression and psychological distress, positive and negative affect (Lawton 1996), as well as articles focusing on the prediction of physical health outcomes (Markides 1989).
An exception to the general decline of sociological studies of QL in the 1980s was a study by Thomas and Hughes of racial differences in QL in the United States (1986), in which they found significantly lower subjective well-being among African-Americans than among whites over the period 1972–1984. In their recent extension of their work to 1996 using data from the General Social Survey, Hughes and Thomas (1998) found that African-Americans continue to have a lower subjective QL than whites, as expressed in terms of happiness, life satisfaction, marital happiness, and self-rated health. This was in contrast to other recent work that challenged the notion that African-Americans had lower subjective well-being. However, much of this work had examined such indicators of QL as psychiatric disorders, including depression (Kessler et al. 1994; Williams et al. 1992). Moreover, one analysis did not find that race magnified the negative effect of socioeconomic status on psychiatric disorders (Williams et al. 1992). Hughes and Thomas conclude that their findings suggest that their measures of subjective QL capture separate dimensions of life rather than measures of psychiatric disorder and that African Americans in all social classes express lower QL of "social life experience" (1998, p. 792). This is an example of how different measures of QL can produce substantially different results.
The relative decline in research on the subjective QL of Americans in general, as well as on the subjective well-being of the elderly during the 1980s, was accompanied by a marked increase in QL research in medicine, which continued to accelerate during the 1990s, both in North America and in Europe. This development has included the publication of the massive Quality of Life and Pharmacoeconomics in Clinical Trials (Spilker 1996), the journal Quality of Life Research, the Quality of Life Newsletter, and the establishment of the International Society for Quality of Life Research. In medicine, as in the social sciences, the field of QL is conceptually weak. As Leplège and Hunt (1997) recently argued, a problem has been the overwhelming emphasis of the medical model on function and health status at the expense of attention to social and psychological aspects of QL as expressed by patients themselves.
Within medicine, there has been particular interest in studying the quality of life of cancer patients. Before 1970, cancer research focused almost exclusively on survival and life extension. With extended survival from cancer becoming the rule, research has given increasing attention to the quality of life of the surviving patients afflicted with cancer or patients treated for cancer. In 1987, for example, a volume entitled The Quality of Life of Cancer Patients was published. The volume, edited by Aaronson and Beckman (1987), contains papers from researchers in a number of European countries as well as the United States. More recently, Gotay and Muraoka (1998) reviewed thirty-four studies published in English language journals from 1980 to 1998 on the quality of life of longterm survivors of adult-onset cancers.
Another parallel to this work has been the focus on active life expectancy. The work has gone beyond predicting extension of life in general to investigating the extent to which recent extensions of life expectancy have been accompanied by extensions of "active" life. A recent variant of this work is the concept of health expectancy or the proportion of life expectancy that consists of healthy years (Olshansky and Wilkins 1998).
DEFINITIONS OF QUALITY OF LIFE
As seen in the previous section, there has been a movement in recent decades away from objective, quantitative research and toward subjective, qualitative assessments of QL in sociology and other fields. Even within these broad approaches to QL, there appears to be little agreement about an appropriate definition of QL.
Some writings include under QL research the social indicators movement. Land (1971) noted that in the early years of the movement, the most popular definition of social indicators was given in Toward a Social Report:
A social indicator . . . may be defined to be a statistic of direct normative interest which facilitates concise, comprehensive and balanced judgements about the condition of a major aspect of a society. It is in all cases a direct measure of welfare and is subject to the interpretation that, if it changes, in the "right" direction, while other things remain equal, things have gotten better, or people are "better off." Thus statistics on the number of doctors or policemen could not be social indicators whereas figures on health or crime rates could be. (U.S. DHEW 1969, p. 97)
Land criticized the above definition and proposed a broader one that treats social indicators as both "outputs" and "inputs" in "a sociological model of a social system or some segment thereof" (1971, p. 324). Thus, for example, the number of doctors is essential to understanding the health of the population, as are other factors. Land's definition has been largely accepted by the social indicators movement (Mukherjee 1989, p. 53).
This article gives only limited attention to social indicators, because a separate article is devoted to the topic. Yet the term "social indicators" is often used interchangeably with "quality of life," at least with respect to what Mukherjee calls "needbased" quality of life research (1989, p. 49). Moreover, the journal Social Indicators Research is subtitled An International Journal of Quality of Life Measurement.
In his book The Quality of Life Valuation in Social Research, Mukherjee notes that QL researchers employ several dichotomies, such as "quantity" and "quality," "behavior" and "perception," and "objective" and "subjective" indicators. He argues:
Economists and planners . . . are almost exclusively concerned with behavioral researchon the basis of quantitative variables to improve the quality of life of the people. In that context, they ignore qualitative variations in the appraisal of a better quality of life or treat these variations as introducing a classificatory . . . distinction in the field of enquiry. They also equate the individual-wise subjective perception of reality to a group-wise "objective" perception by experts. Their appraisal of social reality in this manner leads them to formulate what the people need in order to improve their quality of life. (1989, pp. 37–38).
The dependent variables of this research tend to be items or scales measuring satisfaction or happiness. Milbrath, for example, argues: "I have come to the conclusion that the only defensible definition of quality of life is a general feeling of happiness" (1978, p. 36). Even though such global evaluations have been common, much of the research has focused on describing and explaining satisfactions with various life "domains" such as work, family, and housing.
In discussing subjective indicators of QL, Land notes the difficulties in relating them to objective indicators. He notes, for example, that while income levels tend to be associated with satisfaction and happiness within given countries and at given times, "higher per capita levels of national income do not produce higher average levels of national satisfaction over time or cross sectionally" (1983, p. 5). He goes on to suggest that from the standpoint of generating theory of social change, it is not clear that satisfaction indexes provide an unambiguous criterion for the formulation of public policy.
According to O'Boyle (1997), a more focused definition of QL favored by those in the health field has its origins in the original definition of health by the World Health Organization (WHO) that emphasized the presence of social, mental, and physical well-being instead of only focusing on the absence of disease. The WHO Quality of Life Group offered the following definition:
Quality of life is defined as the individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad ranging concept affected in a complex way by a person's physical health, psychological state, and level of independence and their relationships to salient features of their environment. (WHOQoL Group 1993, p. 5)
MEASURING QUALITY OF LIFE
The broadest and most commonly employed distinction in measures of QL is between objective and subjective measures. Among the former are indicators such as per capita income, average calorie consumption, percent of adult illiteracy, quality of air, average daily temperature, crime rates, life expectancy, and a myriad of other indicators that are best seen as causes of quality of life.
Any one of the above has shortcomings. For example, gross national product (GNP) per capita has been acknowledged to suffer from many well-known limitations, including that it may not capture the spending power of the masses but rather that of a small minority (Mukherjee 1989, p. 42). To overcome the limitations of single indicators, researchers have proposed a number of composite indexes, such as the Physical Quality of Life Index (PQLI; see Morris 1977), which includes, among other variables, life expectancy at birth, infant mortality, and literacy. The purpose of the PQLI is to rank countries by physical well-being. Yet it has limitations, as its proponent acknowledges, including that "it is based on the assumption that the needs and desires of individuals initially and at the most basic level are for larger life expectancy, reduced illness, and greater opportunity" (Morris 1977, p 147).
Another composite index of objective indicators of QL is the Index of Social Progress (ISP) proposed originally by Estes (1984) and revised more recently by the same author (Estes 1988). The latest version (ISP83) consists of thirty-six indicators and is divided into ten subindexes covering "education, health status, status of women, defense effort, economic, demographic, political participation, cultural diversity and welfare effort" (Estes 1988, p. 1). A number of equally important indicators (e.g., crime rates, suicide rates, maldistribution of wealth) were not included because reliable data were not available on the 124 nations studied.
There has also been a lively interest in developing indexes consisting of objective indicators to rank quality of life of American cities on the basis of such domains of QL as economic, environmental, health, education, social, and political. Such rankings of cities elicit national attention and often surprise individuals about how high or low their community ranks. Rankings also do not often correlate with each other. For example, Berger and colleagues (1987) found that their revealed-preference rankings had a correlation of -0.075 with those proposed by Boyer and Savageau (1981) and a correlation of 0.048 with Liu's rankings (1976).
There have been numerous subjective measures of QL, with most relating to happiness or life satisfaction. Some measures are global in the sense that they aim at capturing happiness or satisfaction with life as a whole, while others pertain to happiness or satisfaction with certain life domains. The studies by Andrews and Withy (1976) and by Campbell and colleagues (1976) include measures of both domain-specific and global life satisfaction and employ the former as predictors of the latter. In general, they find that the best predictors of global satisfaction are marriage and family life, leisure activities, work and finances, housing, the community, and friendships.
Well before these landmark studies, W. Wilson (1967) reviewed prior literature on subjective well-being and concluded that the "happy person emerges as a young, healthy, well-educated, well-paid, extroverted, optimistic, worry-free, religious, married person with high self-esteem, high job morale, modest aspirations, of either sex and of a wide range of intelligence" (1967, p. 294). He also concluded that little progress had been made in understanding happiness since the time of the Greek philosophers. Diener (1984) noted that between W. Wilson's 1967 article and 1984, over seven hundred studies on subjective well-being had been published. In general, Wilson's conclusions regarding predictors of well-being appeared to be supported by the literature, including that little theoretical progress had been made in the field since the ancient Greeks.
This voluminous literature on subjective well-being has employed a variety of single-item and multiple-item measures of happiness and life satisfaction. Among the best-known single-item measures are: Cantril's "self-anchoring ladder" (1965), which asks respondents to place themselves on a nine-rung ladder ranging from "best possible for you" to "worst possible for you"; Gurin and colleagues's item (1960), "Taking all things together, how would you say things are these days?" with possible response choices being "very happy," "pretty happy," and "not too happy"; and Andrews and Withy's item (1976), "How do you feel about how happy you are?" with seven choices ranging from "delighted" to "terrible."
A problem with single-item measures is that because internal reliability estimates cannot be computed, the only way of assessing their reliability is through temporal correlation, which makes it difficult to separate measurement error from true change. However, convergence with other measures of well-being has suggested that these single-item measures enjoy moderate levels of validity. They do suffer from other limitations, however, such as positive skewness, acquiescence, and inability to capture the various dimensions of well-being (Diener 1984).
There have also been a variety of multi-item scales employed. Some of the best-known general scales include: the Affect Balance Scale (Bradburn 1969), which consists of ten items capturing positive and negative well-being. Respondents are asked whether in the past few weeks they felt: "particularly excited or interested in something," "so restless you couldn't sit long in a chair," "proud because someone complimented you on something you had done," "very lonely or remote from other people," "pleased about having accomplished something," "bored," "on top of the world," "depressed or very unhappy," "that things were going your way," and "upset because someone criticized you." Summing the positive items provides a positive score and summing the negative ones a negative score. An "affect balance score" is obtained by subtracting the negative score from the positive score. The two subscales have been found to be relatively independent of each other and are sometimes used as different scales of positive and negative affect.
Another multi-item scale is Campbell and colleagues' Index of General Affect (1976), which asks respondents to describe their present lives using semantic differential scales (miserable–enjoyable, hard–easy, boring–interesting, useless–worthwhile, lonely–friendly, discouraging–hopeful, empty–full, disappointing–rewarding, and doesn't give me a chance–brings out the best in me).
Although happiness and satisfaction are often used interchangeably, many writers believe they are distinct measures of well-being. George, for example, suggests that "happiness refers to an affective assessment of quality of life," while "life satisfaction refers to an assessment of the overall conditions of life, as derived from a comparison of one's aspirations to one's actual achievements" (1981, p. 351). Campbell and colleagues (1976) prefer satisfaction measures over happiness measures because they are more sensitive to intervention. While happiness tends to be transitory and volatile, life satisfaction changes gradually and systematically in response to changing life conditions (see also Stull 1987). Satisfaction scales have been particularly popular in gerontology.
QUALITY OF LIFE IN THE ELDERLY
An area in which lively interest has been shown in subjective indicators of QL has been the field of gerontology. As mentioned earlier, use of subjective measures of well-being was particularly high during the 1960s and 1970s, when social gerontologists were occupied with assessing the merits of disengagement and activity theories. In the late 1970s, Larson (1978) reviewed three decades of research and concluded that the most consistent predictors of subjective well-being are self-reports of health.
Although gerontological studies have employed general well-being measures (e.g., the Affect Balance Scale), they have also employed scales specifically developed for use with older people. The two best known are the Life Satisfaction Index A (Neugarten et al. 1961) and the Philadelphia Geriatric Morale Scale (Lawton 1975). The Life Satisfaction Index A consists of twenty items, with which respondents indicate agreement or disagreement. A combined life satisfaction score is obtained by summing scores on all twenty items. Twelve items are positive (e.g., "I am just as happy as when I was younger," "I expect some interesting and pleasant things to happen to me in the future," "As I look back on my life, I am fairly well satisfied") and eight items are negative (e.g., "When I think back over my life, I didn't get most of the important things I wanted," "Most of the things I do are boring and monotonous," "Compared to other people, I get down in the dumps too often"). Because the index covers a variety of areas, including happiness, satisfaction, and "activation level" (see Cherlin and Reeder 1975), the combined score confounds separate dimensions of well-being (Stull 1987).
The Philadelphia Geriatric Center Morale Scale (PGCMS) originally consisted of twenty-two items (Lawton 1972), and the revised version consisted of seventeen items (Lawton 1975). Like the Life Satisfaction Index, the PGCMS consists of positive items (e.g., "I am as happy now as I was when I was younger," "As I get older things are better than I thought they would be," "I have as much pep as I did last year") and negative items (e.g. "Things keep getting worse as I get older," "I sometimes feel life is not worth living," "I sometimes worry so much I can't sleep"). Factor analyses have produced three dimensions: agitation, attitude toward own aging, and lonely dissatisfaction. The scale has problems similar to those of the Life Satisfaction Index, such as the confounding of satisfaction and happiness. The two scales are in many ways similar (in fact, they share some items) and have been found to be highly intercorrelated (r = 0.76; see Lohman 1977).
Liang (1985) attempted to integrate the Life Satisfaction Index A and the Affect Balance Scale by selecting seven items from the former and eight from the latter. His analysis yielded four factors (congruence, happiness, positive affect, and negative affect) that correspond to dimensions of well-being discussed by Lawton (1983). However, Liang acknowledged a gap between the operationalization of well-being and its theoretical operationalization: "Most instruments were developed with only a general conceptual definition, and the sampling of the item domain is usually based on intuition, experience, and empirical experimentation" (Liang 1985, p. 553).
After reviewing the voluminous literature on subjective well-being among the elderly, Gubrium and Lynott (1983) concluded that it was time to "rethink life satisfaction" in old age. One of their key concerns was that the dominant measures employed tended to dwell on the earlier years of people's lives and have less relevance for their current circumstances. In addition, "current measures do not allow for co-equal dialogue between subject and researcher about the content of items and responses" (Gubrium and Lynott 1983, p. 37).
Possibly because of these and other conceptual and methodological problems in subjective well-being measures, we have seen a substantial decline in published studies in major journals aiming at predicting life satisfaction, morale, and related concepts during the 1980s and 1990s. Social gerontologists have instead concentrated on predicting more narrow dimensions of well-being, such as psychological distress and depression (Ferraro and Su 1999; Lawton et al. 1999; Lawton 1996), and are increasingly employing a life-course perspective that involves examination of main and interactive effects of stress, social support, coping styles, and related factors (e.g., George 1989). Measures of depression and psychological distress are being employed more frequently, perhaps because they are perceived as more amenable to intervention than are measures of life satisfaction and morale.
A general conclusion of the field of subjective well-being in the elderly is that most elderly people, particularly those who have reasonably good health and finances, and are socially engaged, report relatively high levels of well-being. According to some literature, elderly people may even report higher levels of subjective QL than do people in younger age groups (Lawton 1996).
STUDIES OF QUALITY OF LIFE IN MEDICINE
Perhaps the most activity in the area of quality of life is currently found in medicine, much of it conducted by behavioral and social scientists. Interest in QL after medical treatments is based on the realization that chronic diseases cannot be cured, and, therefore, the goal of much therapy becomes to limit the effects of illness so that patients may live productive, comfortable, and satisfying lives. Traditionally, success of medical treatment was evaluated in terms of lengthening lives and post-treatment complications. However, there has been a realization that medical and surgical treatments may extend survival but often reduce quality of life (Eisman 1981).
Hollandsworth (1988) reviewed studies evaluating the impact of medical treatment on QL during the period 1980 to 1984 and compared his results with those of studies conducted during 1975 to 1979 (Najman and Levine 1981). Hollandsworth's comparison (1988) revealed a marked increase between the two time periods in both quantity and quality of studies. Although recent studies tended to be more sophisticated, the majority nevertheless relied on convenience samples. One marked improvement in the recent research is the increase in use of subjective measures of quality of life, with 60 percent of the recent studies employing at least one such measure, compared to only around 10 percent in the earlier period.
Another interesting outcome of Hollandsworth's analysis (1988) was the increase over time in the proportion of studies that do not report favorable outcomes. Studies published in the late 1970s were almost unanimous in claiming favorable outcomes of treatment, but this optimism must be tempered by the many methodological limitations of these studies (Najman and Levine 1981). Of the more sophisticated studies published from 1980 to 1984, almost one-half reported either negative outcomes or at least mixed results. In fact, it appeared that the probability of reporting negative outcomes (or lack of positive results) tended to be correlated with the methodological sophistication of the studies (Hollandsworth 1988).
The impact of a variety of medical treatments have been examined, including cardiovascular therapies (e.g., Jenkins et al. 1983; Wenger et al. 1984), end-stage renal disease (e.g., Evans et al. 1985) and chronic obstructive pulmonary disease (e.g., McSweeney et al. 1982). However, by far the most frequently studied area is that relating to outcomes of cancer treatment (see Aaronson 1989; Aaronson and Beckman 1987; Cella and Cherin 1988). Aaronson noted that while "there is no universally accepted definition of the quality of life concept, in oncology it is most often used to describe such aspects of health status as physical symptoms, daily activity level, psychological well-being, and social functioning" (1989, p. 69). This increasing use of subjective QL indicators is becoming an integral part of evaluation in clinical cancer research, but a major challenge facing researchers is the development of measures capturing all dimensions of QL while meeting rigorous standards of reliability and validity (Aaronson 1989).
In a recent review, Gotay and Muraoka (1998) observed that recent studies of cancer survivors have increasingly been using standardized instruments relying primarily on self-reports to assess QL. They identified thirty-four studies published in English-language journals during 1990 to 1998 that focused on the QL of patients surviving five or more years. A variety of standardized instruments were used measuring a variety of aspects of QL. As in other studies of patients, a popular instrument has been the Short-Form 36 Health Survey (SF-36) (Ware and Sherbourne 1992). The SF-36 is a 36-item short form of the Rand Corporation's Medical Outcomes Study. It was designed to be a general measure of health status that can be used in community studies as well as in studies of patients. It consists of multi-item scales measuring eight dimensions of health: general perceptions of health, physical functioning, activity limitations due to physical health problems, bodily pain, social functioning, psychological well-being, activity limitations due to emotional problems, and energy/vitality.
During the 1990s the SF-36 has become the instrument of choice in studies of health-related QL in both community surveys and studies of patients. Like other abbreviated instruments of general health status and QL, the SF-36 has been criticized on a number of grounds, including that it covers some areas only superficially (McDowell and Newell 1996, p. 454).
In their recent critical assessment of QL measurement in medicine, Leplège and Hunt (1997) have criticized the field for relying on instruments (like the SF-36) that have physical, emotional, and social functioning components. While these, according to the authors, are measuring health status, it is not clear that they are measuring QL. This overwhelming emphasis on function, they argue, ignores the person's perspective on the meaning and importance of functions and roles under study. They go on to cite evidence that many physically disabled people do indeed consider their QL to be high despite severe limitations (Leplège and Hunt 1997).
Leplège and Hunt (1997) are also critical of the economic model of QL as expressed in the notion of Quality Adjusted Life Years (QALYs). The concept has evolved over the years as a tool for health policy. Typically, the utility value of specific health status measures, including function and symptoms, during a given period of time is combined with survival data. This perspective usually assumes that rational human beings, if given a choice, would prefer a shorter but relatively healthy life, to a longer life with serious discomfort and handicap. Leplège and Hunt argue that:
the methods used for the valuation of health states do not encompass the fact that the same people value the same state differently at different times, while different people have different preferences that become meaningless if aggregated. The concept of utility . . . operatively addresses what people think they might (or should) do under artificial circumstances and not what they actually do in the real world. (1997, p. 48)
An overview of the literature on medical treatment outcomes does indeed reveal increasing use of subjective QL measures. As in the broader QL field, many studies tend to employ single-item global indicators capturing life satisfaction or happiness. However, an increasing number of studies are employing the general multiple-item measures discussed earlier, such as the Affect Balance Scale and the Life Satisfaction Index Z. Other scales capturing more specific and narrow dimensions of QL include measures of mood, anxiety, self-concept, and depression (Lawton 1996) as well as more comprehensive instruments that capture physical, emotional, and social functioning, such as the McMaster Health Index Questionnaire (Chambers et al. 1982) and the SF-36. A general conclusion of much of the research is that most patients, including cancer patients, demonstrate an incredible capacity to cope with and adapt to the challenges of life-threatening disease and disability. A welcome recent addition to the field has been the development of a variety of diseasespecific QL measures (Bowling 1995).
This brief and selective overview of the field of quality of life indicates a variety of perspectives employed within sociology and in related fields. In fact, it may be said that there is more interest in QL outside the mainstream of sociology, as, for example, in the area of medical treatment. While much of the pioneer work and many of the large-scale national studies in the 1970s were conducted by sociologists, research on quality of life remains very much outside the mainstream of sociology. For example, Schuessler and Fisher's review (1985) uncovered only one article (Gerson 1976) explicitly on quality of life, which was published in the American Sociological Review way back in 1976. More recently, we noted the work of Thomas and Hughes published in 1986 and 1998.
This overview also reveals some patterns and trends in QL research in the last four decades. First, there have been two broad approaches, one focusing on objective indicators and one focusing on subjective indicators. Related dichotomies noted by Mukherjee (1989) include quantity versus quality and behavior versus perception. It is clear that there has been a trend away from relying simply on objective indicators and toward relying increasingly on people's subjective reports about the quality of their lives. Objective measures have been the domain primarily of the social indicator movement, with subjective approaches to QL increasingly perceived as the domain of QL research.
Within the subjective QL approach, we also see a trend away from single-item indicators capturing global happiness and life satisfaction and toward multiple-item scales such as the Affect Balance Scale and the Life Satisfaction Index Z. At the same time, there have been attempts to measure subjective quality of life in specific life domains, and there has been continuing interest by sociologists, economists, and others (including popular magazines) in ranking urban areas according to a variety of objective QL indicators.
During the 1960s and 1970s a great deal of subjective QL research was conducted by social and behavioral gerontologists, who used measures of life satisfaction and morale as indicators of successful aging. For a number of reasons, gerontologists began abandoning research on life satisfaction and morale in favor of measures more amenable to intervention, such as measures of psychological distress, depression, and physical health function. Perhaps the most exciting research on QL currently being conducted is in the area of medical treatment outcomes, particularly cancer treatment. In this field, as in others, there is considerable disagreement about what constitutes quality of life and how it should be measured.
It is becoming increasingly difficult to obtain funding to conduct large-scale national surveys of subjective quality of life such as those conducted during the 1970s. The future of QL research is uncertain, at least as a broad unified field of inquiry. Studies ranking urban areas are likely to continue, because of the immediate and broad appeal they elicit. It is also safe to predict that the concept of quality of life will continue to have some appeal in social gerontology. The most exciting work may well take place in the area of medical intervention outcomes. Sociologists and other behavioral scientists are increasingly conducting research related to medicine, and much of this research relates to quality of life. It is becoming apparent that medical interventions (as well as other factors) are enabling us to live longer, but it is not clear that the added years of life are "quality" years. There will be increasing interest in finding ways to improve the quality of the added years, and sociologists have an opportunity and a responsibility to help find ways of accomplishing that.
(see also: Social Indicators)
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Kyriakos S. Markides
Quality of Life
QUALITY OF LIFE
Before the 1970s, quality of life received little attention in the medical or public health literature, but since then the situation has been reversed. Despite its widespread use, the term "quality of life" has different meanings to different people. For some researchers and clinicians, quality of life means almost anything beyond information about death and death rates. For others quality of life is an umbrella concept that refers to all aspects of a person's life, including physical health; psychological well-being; social well-being; financial well-being; family relationships; friendships; work; leisure; and the like. In contrast, some approaches to quality of life emphasize the social and psychological aspects of life, and contrast quality of life with quality of care.
Variation is also found in measurement strategies. Some scholars believe that quality of life can be measured by objective parameters. For example, the quality of life in a city is sometimes measured by a summary of characteristics such as the schools, the cultural offerings, the aesthetic properties, the climate, the health care system, the employment possibilities, and so on. By the same token, characteristics of a person, such as income, health status, mental health status, disease profiles, educational level, and housing situation can be summed to create an overall quality-of-life measure. Others view the objective parameters that are often associated with quality of life to be indicators, whereas the actual quality of life can only be measured by a subjective appraisal made by the individual living the life. If one believes that quality of life is inherently subjective, it is then possible to test indicators by the extent to which they predict the quality of life reported by groups of people.
Why is quality of life of interest for public health? First, a good or a poor quality of life is, in some ways, the ultimate marker of the success of preventive health practices and of health care. Second, many health care regimens often seem to detract from quality of life, at least in the short run. As individuals, with the help of their physicians, make decisions about treatment choices, they may take quality of life into account, and may seek information about the likely effects on the quality of their life. Third, and related to the previous point, recent rhetoric pits quantity of life against quality of life, especially in terms of end-of-life treatments; the argument is sometimes made that some treatments are inadvisable because the quality of life likely to result for the extra time gained is too poor. Thus, quality of life has come to be seen as a gold standard for weighing the benefits and costs of life-extending treatments. Finally, in some circumstances, people are asked to change their life circumstances, perhaps forever, for the sake of their health status and care. Relocation to a nursing home would be an example of such a dramatic change. In that situation, it is incumbent on those who plan, fund, and license nursing homes to have some way of assuring that the quality of life, in so far as it is influenced by the facility, is of an acceptable standard.
In health care, the term "health-related quality of life" (HRQL) is often used. This approach narrows consideration to those aspects of quality of life that are deemed to be affected positively or negatively by medical or health care intervention. Another important distinction is between a general HRQL measure (e.g., one that asks about quality of life affected by health) in contrast to a disease-specific HRQL measure. A disease-specific approach may pose questions in relation to the effects of a particular disease (e.g., cancer, arthritis, heart disease) and its treatment with items such as "have you experienced reduction in social activities because of your condition." Other tools are comprised of objective items (for example, agree-disagree items) that are thought to be particularly relevant to the particular disease. A generic HRQL measure may simply be a general measure that attempts to tap health status using the full range of the World Health Organization's definition of health: "physical, psychological, and social well-being."
Subjective judgments of quality of life, though logically the best single source of information, are prone to be influenced by a number of factors. First, expectations influence appraised quality of life, so that an individual may become used to circumstances that could objectively be considered substandard. (This criticism also applies to measures of satisfaction.) Second, individuals may feel constrained because of courtesy or intimidation from actually expressing their views. The intimidation is more likely if the person is in vulnerable health and perceives himself or herself as dependent on care providers, a circumstance that is common for nursing home residents. Finally, lifelong personality traits may influence perceived quality of life.
Personality is generally classified according to five traits (each of which can be seen in their expression or their opposites): neuroticism, extroversion, agreeableness, conscientiousness, and openness. Although little large-scale psychological or sociological research has been done to link subjective quality-of-life results to personality, anthropologists have observed patterns that suggest underlying personality is very much related to how individuals view the quality of their life.
MEASURES OF QUALITY OF LIFE
Examples of some general HRQL measures in widespread use include the Sickness Impact Profile (SIP), which was developed by Bergner and colleagues in the 1970s, and the Medical Outcomes Studies (MOS) Short Form, known as the SF-36, developed by John Ware and colleagues. The SIP, which was developed in the 1970s, contains 136 items that tap twelve categories of wellbeing: sleep and rest, eating, work, home management, recreation and pastimes, ambulation, mobility, body care and movement, social interaction, alertness behavior, emotional behavior, and communication. As its name suggests the SF-36 contains thirty-six questions and generates scores in eight categories: physical functioning, role limitations due to physical problems, social functioning, bodily pain, general mental health, role limitations due to emotional problems, vitality, and general health perceptions; an SF-12 is also available that provides summary scores for physical and mental functioning.
The best known approach specifically for elderly people is the Multi-level Assessment Instrument (MIA), developed by Lawton and colleagues; this is a 152-item battery that generates scores in seven areas: physical health, cognition, activities of daily living, time use, social relations and interactions, personal adjustment, and perceived environment. More recently, Kane and colleagues have been conducting research to develop a self-report measure of the psychosocial aspects of quality of life for nursing home residents: Their eleven domains include comfort, functional competence, autonomy, dignity, individuality, privacy, relationships, meaningful activity, sense of security and safety, enjoyment, and spiritual well-being.
The Quality of Well-being (QWB) Scale, developed by Kaplan and colleagues, differs from the approaches so far described because it defines quality on twenty-four functional states on a scale ranging from 0 for death to 1 for perfect health. The scoring weights were developed based on preferences that individuals assign to the various states.
USING QUALITY OF LIFE FOR RESOURCE ALLOCATION
Some policy analysts recommend using information about quality of life under certain conditions to make decisions about the relative value of health expenditures. The term "quality-adjusted life year" (QALY) is used for approaches that try to combine the effect an intervention will have both on prolonging life and the quality of that life. For example, it would be assumed that extending life for a year for someone in a coma is not as worthwhile as adding a year of vigorous function. The QWB scale described above lends itself to a QALY approach.
Technical and ethical questions arise in applying QALY. Among the former are issues of whether those who rate the conditions have sufficient understanding to apply the judgments. It is widely known that people who do not have a particular condition devalue life with that condition more than those who actually experience the disease or health state. It is also likely that there are cultural and social class differences in how various states are valued. In a well-publicized project, the Medicaid program in the state of Oregon ambitiously applied a QALY approach to Medicaid expenditures for a wide range of conditions. A series of town meetings and phone surveys elicited public opinion about the value attached to the conditions and was combined with physicians' estimations of the magnitude and duration of effects of medical interventions. These were combined with cost information to generate a rank-ordered list of priorities. This procedure yielded results that gave a higher priority to treatment of some common conditions than to much more severe but treatable conditions affecting fewer people.
The most serious criticism of QALY measures is that, as they have been developed and applied, they seem to discount the value of the lives of people with disabilities and very elderly people. If the upper boundary of quality of life is having no functional limits, then certainly quality of life for older people is deflated. An approach called "active life expectancy" developed by gerontologists has this problem: Once the individual is dependent, he or she has no more years of active life expectancy left under the measure.
PROXY EVALUATIONS OF QUALITY OF LIFE
Even if subjective appraisal is treated as a gold standard, some people will simply be unable to communicate about the quality of their lives, and alternative sources of information must be sought. This will be particularly true of people with severe cognitive impairments such as Alzheimer's disease, or people who suffer the communication and motor problems associated with stroke (which could prevent both written or oral administration of a questionnaire). It is, of course, also true of very young children, including newborn children with disabilities that are believed to severely compromise the quality of their current and expected future lives. The hospice movement has stimulated interest in appraising quality of life at the time of death, yet many people cannot be effectively queried on the subject in the last few days of life.
Under these circumstances, the choices of information sources seem to be limited to three: family members, health professionals or paid caregivers of various types, and/or direct observations of the person, from which inferences about his or her quality of life are drawn. All of these approaches have been applied with and for people with Alzheimer's disease. Some of the work in this regard was stimulated by the growth of special care units (SCUs) for Alzheimer's disease in nursing homes, and the resulting need to determine whether residents experienced a different quality of life on those specialized units than in the general population. The direct observations include repeated systematic observation of the individual's facial expression and body language for signs of positive or negative emotion. Similar multifaceted approaches have been developed for adults with intellectual impairments due to developmental disability. However, caution is recommended in resorting to proxy informants too quickly or widely. Many seniors with Alzheimer's disease and younger people with mental retardation are, nevertheless, capable of evaluating many aspects of their lives. Moreover, when it has been possible to get information from both the person most concerned and other informants, a growing body of studies show that family members and professionals may rate quality of life differently from the ratings of those living the life.
The growing attention to quality of life and the desire to minimize the negative effects of disease and health care on this quality reflects the highest of public health aspirations. The science of measuring quality-of-life outcomes is still under development and a matter of some controversy. Also at issue is the extent to which public health measures and health care provision can and should attempt to influence quality of life broadly, and whose values should inform the definitions of quality.
Rosalie A. Kane
(see also: Assessment of Health Status; Functional Capacity; Gerontology; Health Outcomes )
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quality of life
The most commonly used indicators are straightforwardly economic—such as per capita GNP—but increasingly even economists recognize that these are crude measures of a citizen' quality of life. An alternative ‘capability approach’ suggests that the quality of life each person leads corresponds to the freedom that he or she has to live one kind of life rather than another. This is reflected in the combination of doings and beings (‘functionings’) that are possible, ranging from elementary matters such as being properly nourished and healthy, through to much more complex functionings such as having self-respect, preserving human dignity, and taking part in the life of the wider community. This approach suggests that an adequate measure of quality of life must be plural and should recognize that distinct components of well-being are irreducible to each other.
The Level of Living Surveys set up by the Swedish government to measure the welfare of individuals, and conducted periodically since 1968, use a wide variety of indicators. These measure (among other things) health and access to health care (ability to walk 100 metres, various symptoms of illness); employment and working conditions (unemployment experiences, physical demands of work); education and skills (years of education, qualifications obtained); housing (amenities, and number of persons per room); security of life and property (exposure to violence and thefts); and recreation and culture (vacations, access to leisure facilities)— as well as the more obvious economic resources (income, wealth, property, and so on).
Debates about the quality of life are not unlike discussions of poverty and deprivation; for example, the same issues of cultural relativism are raised, and similar measurement problems arise. Should measurement be related to the needs or resources of individuals? Which indicators should be used and how can these be summarized to give an overall picture of quality of life? (How do we compare a rich man who suffers from an untreatable illness which interferes with his enjoyment of life and a poor woman who keeps perfect health and enjoys life?) For a useful and wide-ranging discussion of the concept and the many methodological issues it raises see Martha Nussbaum and and Amartya Sen ( eds.) , The Quality of Life (1993