Quality of life: a critical review of current concepts, measures and their clinical implications

hr. f. Nun. Yud.. Vol. 26. No. 4. pp. 327-341, Printed in Great Britain.

1989.

cmo-748909 13.00+0.00 % 1989 Pcrgamon Press plc

Quality of life: a critical review of current concepts, measures and their clinical implications SUSAN M. GOODINSON,

R.G.N.,

B.Sc.

Lecturer in Nursing Studies, Department of Biochemistry, University of Surrey, Guildford, Surrey GU2 5XH. U.K.

JANE SINGLETON,

B.A., D.Phil.

Senior Lecturer in Philosophy, Division of Psychology, School of Health and Human Sciences, Hatfield Polytechnic, Hatfield, Herts AL10 9AB. U.K.

Abstract-Quality of life (Q/L) measurements are used to justify or refute different forms of medical treatment; to identify the sequelae of disease or treatment which are resolved by other interventions including nursing and to provide a basis for allocating resources to those treatments judged to be most cost-effective. This paper reviews some of the difficulties in defining and measuring Q/L and the ethical issues raised in relation to their use in allocation of treatment resources. It is suggested that Q/L tests should include a range of dimensions known to contribute to Q/L and that they are applied at different times during the progression of illness and incorporate information obtained from patients. It is essential that weightings by individuals of dimensions investigated in the test are included. Further research is necessary to determine the effects of coping strategies and personality variables on Q/L.

Introduction

During the last decade the elusive, multi-dimensional concept of quality of life (Q/L) has generated a growing focus for research, controversy and debate in the field of health care. 327

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The concept has been discussed in two major contexts. In the first it has been discussed in the context of treatment selection and therapeutic approaches and in the second it has been used to develop a new concept, that of the quality adjusted life year (QALY) (Kind et al., 1982). With reference to treatment selection and therapeutic approaches, Q/L is arguably defined as “the degree of satisfaction with perceived present life circumstances” (Young and Longman, 1983). It encompasses the physical, social and material well-being of an individual. Brody (1976) identified the quality of patients’ lives as one of the most crucial issues in medical ethics, yet Bardelli and Saracci (1978) found it to be measured as an end point in only 4% of the controlled therapeutic trials in cancer during 1975-1976. Furthermore, survival and recurrence-free survival were the very limited end points most commonly used in many of these early studies (McPeek et al., 1977). Until recently, few investigators had attempted a wider evaluation of the physical, psychological and social impact of disease and treatment on patients’ lives, no doubt reflecting the lack of consensus on definition, interpretation and methods of measuring life’s quality. The second context in which Q/L has been discussed is in the conceptualization of the QALY, developed from an economic perspective. Williams (1985) has stated that “the objective of economic appraisal is to ensure that as much benefit as possible is obtained from resources devoted to health care. In principle, the benefit is measured in terms of effect on life expectancy adjusted for Q/L”. Few studies have attempted to measure Q/L in these terms. It is also important to note that the prospective use of the QALY raises ethical issues which merit serious consideration.

Rationales for measuring Q/L Diverse reasons for the measurement and uses of Q/L indices are encountered in the literature. Those most commonly cited include: to justify or refute different forms of medical treatment, to resolve dispute concerning different therapeutic approaches, to identify the sequelae of disease or treatment which may be resolved by other therapeutic interventions (e.g. nursing) and with regard to the QALY, to provide a basis for allocating resources to those treatments judged to be most cost effective. Advocates of the QALY suggest a further use, as a basis for treatment selection between individuals, favouring those who have the potential to maximize benefit, i.e. the number of QALYs. Treatment selection and justification. In early Q/L studies, the end points most commonly used to evaluate treatment were rates of cure, survival, response and duration of response. The realization that many therapeutic procedures have the potential to cause unpleasant side effects has emphasized the fact that it is not cure and survival alone which are important, but that the Q/L of the individual is also of paramount consideration. As Greer (1984) has emphasized, this is in accordance with the precept of primum non nocere which has long under-pinned the ethical basis of therapeutics, interpreted to mean that the benefits of treatment must be greater than the suffering which may be entailed. Stoll (1977) has made the valuable point here, that Q/L must be of prime concern as many chronic diseases are not curable. For many, palliation or symptom control are the reality. Hence the introduction of any qualitative considerations, in addition to quantitative dimensions, automatically raises the question of the relative weightings to be given to quality of life and duration of life. Quality of life studies could be used to supply information about the progression of a disease and its impact on patients’ lives. From measurements made prior to, during and

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after different treatments, it may be possible to compare their relative efficacy, a crucial matter in the selection and justification of treatment of others. For example, if both surgery and radiotherapy were the therapeutic options available to treat a particular form of malignancy and both were found to exert an equal impact on survival length, but surgery had more beneficial effects on quality of life, then the preferential use of surgery could be justified. In situations where the choice is either a therapy which confers increased survival time, or one which gives a better Q/L, then the informed, autonomous decision of the patient, after discussion with the medical practitioner, should be respected. With reference to such decisions, Glover (1977) has commented that for many individuals, Q/L is not altogether independent of its length as many plans and aspirations which make a pivotal contribution to it, would not be worth undertaking without a good chance of their fulfilment. If Q/L measurements are to be used to differentiate between the merits of alternative treatments for a given disease, then a number of questions must be resolved. Is it possible to separate the continuing impact of the disease from that of the therapy? How do we know that the measurement of the impact of therapy is exclusive of other variables such as coping strategies, personality characteristics, nutritional status and psychological state? Could the merits of different therapies depend in part on fallible judgements about the criteria which determine Q/L and are included in the study method chosen? Finahy, can findings on Q/L derived from post-treatment groups ever be generalized as a basis for decision making for individuals who have not yet started treatment? Identification of other therapeutic approaches. De Haes and van Knippenberg (1982) and Clark and Fallowfield (1986) have identified another valuable use of data obtained from Q/L studies; distressing symptoms which are associated with the disease or treatment and are amenable to intervention are highlighted. Examples cited in a review by Greer (1984) were the feelings of personal inadequacy, anxiety, depression and sexual difficulties which are the result of mastectomy in a significant minority of women and may be resolved by psychological support. Similar findings have emerged from Q/L studies in patients with bowel cancer who have undergone formation of a permanent colostomy (Devlin et al., (1971); Wirsching et al., 1975). Changes in appearance, tiredness, loss of concentration and mobility emerged as the symptoms causing major distress in a recent Q/L study in oncology patients (Holmes and Dickerson, 1987). Such findings emphasize the relevance of Q/L investigations for nursing care, as the nurse plays a major role in the resolution of such problems. Padilla and Grant (1985) have suggested that Q/L indices may be used to evaluate the impact of nursing on the cancer patient. These authors highlight the crucial role of the nurse in assisting the patient to cope with side-effects of treatment and suggest that nursing interventions can exert an important impact on quality of survival. In their study of 135 post-colostomy patients, satisfaction with nursing care as measured by nurse availability (itemized as anticipation and response to needs for information and analgesia), demonstrated a significant positive correlation with the patient’s physical and psychological well-being and social concerns. However, the potential use of Q/L indices to evaluate the impact of nursing care requires further careful consideration and research, as it may not always be possible to separate the contributions of nurses from those made by other health professionals. Applications of the QAL Y. The two proposed applications for QALYs cited above are, as a measure to be used in the allocation of NHS resources and second as a measure to determine which individuals should receive the available treatment.

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Treatments are assessed according to the number of QALYs that they would yield coupled with the cost of these QALYs, which would clearly vary from treatment to treatment. For example, the following figures have been given by Williams (1985): Heart transplantation yielding Kidney replacement yielding Hip replacement yielding

4.5 5 4

QALYs at a cost of f5,OOO per QALY QALYs at a cost of f3,OOO per QALY QALYs at a cost of f700 per QALY

On this basis QALYs would be maximized by a transfer of resources to hip replacement treatment away from heart or kidney transplantation.

Defining Q/L: a basis for developing Q/L measures Questions concerning which features of life or ‘universal goods’ are of intrinsic value and which may contribute to its quality have been debated for centuries. One useful theoretical basis from which a definition could be developed, would be to identify the features, conditions or domains of life which are necessary for us to function as independent and autonomous beings. Are there some which are relevant to us all and others which are unique to each individual? A general consensus might be reached on freedom of action, a sense of purpose, achievement in one’s work or family life, self-esteem, integrity and the fulfilment of some fundamental aspects of biological and psychosocial function in relation to activities of daily living and the maintenance of health. Such features are encompassed in the broad definitions of Q/L by Lewis (I982), “the degree to which one has self-esteem, a purpose in life and minimal anxiety”, and Hornquist (1982), “the degree of need-satisfaction with the physical, psychological, social, material and structural areas of life”. Happiness or satisfaction?. Other broad definitions have also encompassed concepts of happiness and satisfaction in relation to Q/L. Dalkey and Rourke (1973) defined Q/L as “a person’s sense of well-being, his satisfaction/dissatisfaction with life or happiness/unhappiness in dimensions of health, activity, stress, life-goals, self-esteem, depression, social and family support”. A number of problems are inherent in using ‘happiness’ in this context as it is difficult to define, describing moods of gaiety and elation which can be evanescent. The concept is also subject to great difficulties in interpretation between cultures and languages. Campbell et al. (1976)suggest that the use of ‘satisfaction’ is a better indicator of quality of life because it implies cognitive judgement of a situation in which external standards are used for comparison. Satisfaction can also be defined more precisely as, ‘the discrepancy perceived between aspiration and achievement’. These authors also make the point that it is important to differentiate between satisfaction associated with rising expectations where goals are achieved, i.e. the satisfaction of success and that associated with declining expectations and resignation. In support of using ‘satisfaction’ in defining quality of life, Campbell (1981) and Laborde and Powers (1980) have found that, when questioned about the quality of their lives, apparently healthy individuals respond in terms of life satisfaction, usually in relation to specific domains. It is essential to recognise that satisfaction with particular domains can vary greatly between individuals and that for each individual the relative importance of domains varies over a life time and each does not impact equally on quality of life (Ferrans and Powers, 1985). Campbell ef al. (1976) used satisfaction in several domains both to define and measure Q/L. These included marriage, family life, friendships, standard of living, finance and religion. Satisfaction with a specific domain was seen to be dependent upon the individual’s

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evaluation of its attributes, in turn dependent on perceptions, internal reference standards, judgement and the discrepancy between aspiration and expectation. Studies in ‘normal’ healthy populations suggest that the domains which tend to be rated most highly are a happy marriage, good health and family life, whilst in a longitudinal study of persons aged 46-70 years, self-rated health, social activity and sexual enjoyment were significantly related to life satisfaction over a four-year period (Palmore and Knivett, 1977). There are general problems in using ‘satisfaction’ in defining quality of life. For example, what is the rational way to treat the timings of satisfactions? Is it rational for an individual to discount future satisfactions or dissatisfactions in favour of present ones? Rosser (1985) states that a preliminary study has been made of the rate at which subjects discount the scaled severity of future states of ill-health. On the other hand, is it rational to consider satisfactions, as far as possible, over the whole of one’s life? It has been argued that a version of the former view, The Present Aim Theory, as opposed to the latter view, The Self-Interest Theory, is the rational view to take (Parfit, 1984). This point raises the questions of whether people’s expressed views about their satisfactions ought to be considered, or whether these views should be adjusted in the light of what is considered a rational view about the temporal weightings of satisfactions. Life plans. Is quality of life the ability to live one’s life according to one’s own plan and fulfil the aspirations and goals contained therein? If this is the case, quality of life is determined by those features or ‘universal goods’ which permit realization of an individual’s life plan. “It is the plan and the inter-related purposes of a person that give his/her life what unity it has and bring us to regard them and ourselves as individuals who are irreplaceable”. Thus, Cohen (1982) in propounding the views of the philosopher Royce (1908), suggests that a useful basis for theorizing about life’s quality is to consider the extent to which its desirable features advance or hinder one’s ability to live according to plan. Features of life which make a positive contribution to realization of the plan could be, pursuit of vocation or art, special interests, and pleasures in relation to music, sport or family. As with other approaches to Q/L, some components could be discerned as common to all life plans and some peculiar to the individual. The notion of a plan also incorporates the idea of goal fulfilment at different stages over a period of time. In relation to the effects of medical or nursing treatments, success or failure could be judged by the impact on plan fulfilment or frustration. Although the features which mark plan fulfilment bear similarities to satisfaction within the life domains identified by Campbell and others, this life plan approach of Cohen’s in theorizing about quality of life is unique in the literature on this subject. Inherent in Cohen’s approach to quality of life is the emphasis placed on the individual, also explicit in the definition of Fayos and Beland (1981), “the ability of patients to manage their lives as they evaluate it”, De Haes and van Knippenberg (1982) “an overall evaluation of the subjective experience of life”, i.e. directly based on individual experience. The ‘overall’ perspective is also emphasized in Szalai’s definition (1980) of Q/L “the global evaluation of the good or satisfactory character of people’s lives”. Approaches to Q/L measurement Obtaining useful, quantitative information about the quality of patients’ lives poses several formidable questions for the clinician. Which dimensions should be included in an attempt to assess the impact of disease and therapy on the patient’s life? Should a subjective or an objective approach be adopted? Is a global evaluation more appropriate

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or useful than one which relies exclusively on the assessment of symptom distress? Finally, what instrument may yield the most useful quantitative information? What are the merits of visual analogue scales vis ci vis Likert scales or questionnaires? In addition, it is essential to know whether the instruments chosen for Q/L investigation have been subjected to rigorous reliability and validity testing on clearly defined populations of patients and controls. Scrutiny of the literature on Q/L illustrates the tremendous variation in approach that clinicians have adopted in an attempt to resolve such questions. In general, two extremes in approaches to Q/L measurement must be considered; the ‘global’ evaluation which assesses many dimensions of Q/L and the more restricted evaluation of disease or treatment related symptom distress. The ‘global’ evaluation possesses the advantage that it gives some overall sense of well-being, but as Selby (1984) has commented, this is at the expense of assessing a dominant symptom which may exert a significant impact on Q/L and, moreover, be amenable to intervention. Such an approach also tends to be time consuming and demanding of participants. Similarly, an approach which restricts measurement to symptom distress alone, may fail to assess effectively, the impact of disease and treatment on a patient’s whole life. Several approaches include, either wholly or partially, ‘objective’ measures. This can refer to the fact that the information is not obtained from patients but from medical/nursing staff involved in their care, or by a trained researcher. Exactly how valuable is this? Campbell (1981) has emphasized, that in order to know the Q/L experienced it is necessary to go to the individual themselves to obtain a description of how life feels. Surely the individual is the only one capable of weighing satisfactions and dissatisfactions and making judgements? In relation to this, the work of Spitzer et al. (1981) is particularly interesting, as reliability testing of their Q/L index (p. 336) demonstrated a consistent trend by patients to rate themselves one or two points higher than their physicians! Other approaches interpret ‘objectivity’ to mean the incorporation of data such as income, education, return to work, time of work before and after surgery, length of survival, disease free intervals, changes in tumour volume and drug requirements before and after treatment (Ross and Diweel, 1978; Hochberg et al. 1979). Whilst this information is useful, again it does not assess the impact of therapy on the patient’s whole life. Campbell (1981) suggests that such objective indicators merely measure factors that influence the experience of life, whilst ‘subjective’ measures assess the experience directly. Great confusion is evident in the research literature vis 6 vis ‘objectivity’, referring either to the content of information (as above) or to persons other than the patient eliciting it. Physical function or activities and psychological well-being are the dimensions most commonly used to assess Q/L both in apparently well adults and in patients undergoing therapy. Fewer investigators have considered social support, family or marriage in their studies, despite the evidence supporting these as some of the most important factors (Palmore and Knivett, 1977; Neugarten et al., 1961). Apart from difficulties in selecting the dimensions of life chosen for investigation, there are also a number of methodological problems. In many studies the populations used were very small and selection criteria were omitted. De Haes and van Knippenberg (1982), in their comprehensive review of Q/L studies in cancer patients, noted the absence in many reports of evidence of reliability and validity testing. Where content validity is considered, it is mostly culled from the literature constituting expert opinion; the views of patients were considered in few studies (Spitzer et al., 1981; Ferrans and Powers, 1985; Bergner

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Table 1. Examples of content in four approaches to Q/L measurement Visual analogue scales Q/L dimensions assessed (a)

Padilla and Grant (1985)

Physical strength; sleep; fatigue: anxiety; body weight; sexual activity; present state of health; ease of adjustment to colostomy; hobbies; recreation; social activity; eating; performance of what tasks; usefulness; happiness; life satisfaction; pain; quality of life; fear of colostomy leakage; contact with friends or family; rejection; privacy.

Sample questions How much pain do you feel?

Non?

Excruciaiing

How satisfying is your life?

Not at all

Extremely satisf?ng

I Do you tire easily? Not at all

(b)

Selby (1984)

Work; home management; mobility; alertness, recreation; eating; sleep and rest; social interaction; body care and ambulation; emotional behaviour; communication; pain; breathing; sore mouth; attractiveness; appearance; dysuria; constipation; diarrhoea; fatigue. Quality of life indices Q/L dimensions assessed

(a)

Spitzer (1981)

Activity; living; health; support; outlook on life.

All the time

Subjects were asked to score how they felt each dimension of life was affected by the state of their health. For emotional behaviour questions were included on anxiety, depression and anger, e.g. Extremely

Not depressed

Sample questions During the last week the patient: has been working or studying fulltime or nearly so in their usual occupation or managing their own household or participating in unpaid voluntary activities whether retired or not; Score 2. has been working or studying in their usual occupation or managing their own household, or participating in unpaid voluntary activities but requires major assistance, or a significant decrease in hours worked, or a sheltered situation, or has been on sick leave; Score 1. has not been working or studying in any capacity and not managing their own household. Score 0. Table I continued over

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SINGLETON

Table I continued

Quality of Life Indices Q/L dimensions assessed @) Ferrans and Powers (1985)

Sample questions

Thirty-two items in each of two sections, one measures satisfaction with domains of life; the other the importance of the domain to the individual.

Subjects were asked to rate their satisfaction with each item and the importance of each item to them on a six point Likert scale.

Items assessed included health care; physical health; marriage: family; friends; stress: standard of living; occupation; education; leisure; future retirement; peace of mind; life goals; personal faith; appearance: self-acceptance; general appearance; self acceptance; general happiness and general satisfaction.

Anchor words for each extreme point of the scale were; very satisfied and very dissatisfied. Very important and very unimportant.

For renal dialysis patients three additional items in each section were added.

and Bobbit, 1981; Selby, 1984). Examples of content in four approaches to Q/L measurement are summarized in Table 1. There are problems in testing the reliability of Q/L instruments. A test-retest index alone may not suffice as Q/L may fluctuate dramatically during certain treatment periods, e.g. immediately following chemotherapy. Najman and Levine (1981), in a critical review of the impact of medical therapy on Q/L, also highlight the care which must be taken when designing Q/L studies and extrapolating the findings of small, descriptive investigations to a wider population. It is difficult to ascertain whether Q/L (the dependent variable) is influenced by treatment or stage of disease (independent variables) or other variables (nutritional status, personality type, coping strategies) unless a randomised control group is used for comparison. However, as Greer (1984) has emphasized in relation to studies on cancer patients, truly randomized, controlled clinical trials of therapies are a vexed issue, raising a number of ethical questions. Examples of approaches to Q/L measurement Karnofsky Performance Index (Karnofsky and Burchenal, 1949). This approach to measurement, devised nearly four decades ago, is that most commonly used by clinicians. It assesses ‘health performance status’ in relation to physical activities only, hence the single dimension used to assess Q/L is a major limitation on its usefulness. For example, an individual who has suffered a stroke and is paralysed, but has enormous family support, could obtain a low score, while an ambulant patient with cancer who is severely incapacitated by depression could score highly. As originally devised, the Karnofsky index consists of 10 questions which are answered on a rating scale of O-100, with 0 the terminal lower point (dead) and 100 the zenith of normal (with no evidence of disease). The test is scored by a clinician and does not in any part represent the subjective views of patients. Although

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possessing concurrent, convergent and predictive validity, Hutchinson (1979) and Yates (1980) have found a poor reliability, demonstrating a test-retest index of 0.66 and interrater reliability of 0.69. This would seem to be a very limited method of assessing Q/L. Visual (Linear) Analogue Scales (VAS). The use of visual analogue scales for Q/L assessment has increased in popularity. This form of measurement utilizes lines O-100 mm long, denoting a continuum of dimensions in emotional, physical or social experience, with anchor words or phrases marking the extremes. The patient marks a point on the line which corresponds to their perception of the experience (e.g. pain) and is assigned a score out of 100. Scores for different scales can be added to obtain an overall Q/L score if this is desired. This method is very sensitive (cf. Likert scales), subjective and usually quick to complete, but for elderly patients it may be time consuming as physical weaknesses may distort the process of scoring and the use of fixed end-points may produce the well known ‘ceiling’ effect. Another problem is that other factors may impinge on the experience measured, for example responses on a pain VAS may be negatively affected by anxiety or depression. In some of the examples cited below, two other problems arise. Firstly, all the experiences assessed are given equal weighting, so that improvements in some are marked by a diminution in others, limiting the value of the overall score as a Q/L measure. As described before, many of the experiences in different dimensions of life will be weighed differently by individuals, so a sensitive and accurate assessment tool must consider these carefully (few do!). Priestman and Baum (1976) used VAS successfully to evaluate Q/L in patients receiving two different forms of chemotherapy for advanced breast cancer. The experiences measured related to the effects of the disease, physical and psychological function and personal relationships. Patients co_mpleted the assessment before and after treatment and test-retest reliability was 0.87. No differences in impact on Q/L were found between the two drug regimes, but an interesting finding was a fall in VAS scores with successive courses of cytotoxic drugs, suggesting that patients may adapt to their side-effects over time. The authors note the need to assess items on feelings, performance and symptoms separately, rather than adopting an indiscriminate mix to ordering. Padilla and Grant (1985) have also used VAS to assess Q/L of colostomy patients using a multidimensional approach which included physical function, personal attitudes, affective state, family support and specific items related to management of the colostomy (Table 1). This VAS instrument was subjected to rigorous validity testing and possesses content, construct, concurrent and discriminant validity. Reliability was established with a test-retest index of 0.88 and coefficient of 0.88. Selby (1984) has also designed and evaluated a VAS method of collecting information about the quality of life of breast cancer patients. The dimensions investigated were comprehensive and included 18 items on general health derived from a sickness impact profile (Bergner and Bobbit, 1981). These cover work, home, marriage, hobbies, mobility, alertness, sleep, rest, social-life, emotional behaviour, communication, family and relatives. A further 12 items on major problems associated with the treatment of breast cancer were derived from patients’ expert opinions (Table 1). Items were all randomly ordered to reduce the possibility of scores on adjacent related scales influencing each other. The authors avoided adding scores into a summary number for each patient and have exhaustively evaluated reliability and validity for individual items-a unique approach in Q/L measurement-suggesting that this is of greater use to the clinician than an overall Q/L score. Some aspects of validity require further study using

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this approach in a larger number of individuals. Poor agreement was found, for example, with patient item scores for anger and sleeping (Selby, 1984). Quality of life indices (Spitzer, 1981; Ferrans and Powers, 1985). Spitzer’s (Spitzer et al., 1981) assessment tool used a unique ‘Apgar-like scale to measure Q/L. Dimensions (5 only) were investigated: activity, daily living, health, support and outlook (Table 1). In relation to each, a crude scoring system in which 2 equates with normality, 1 with some degree of impairment and 0 with not managing, is used. Scores are added to give a value out of 10. Equal weighting was given to all dimensions assessed, which confers limitations described earlier and another problem was the inclusion of several items in one statement, with inevitable loss of specificity. The assessment is carried out by physicians not patients, although content validity is based on patients’ and others’ views. Test-retest correlation was satisfactory at 0.88 and the instrument has been subjected to content, predictive and discriminant validity testing. Ferrans and Powers (1985) have designed a very different form of Q/L index, evolved from studies on healthy populations of students and patients on haemodialysis programmes. The 32 items that were assessed related to physical health, marriage, family, friendships, stress and others related to dialysis treatment, specific to patients only (Table 1). Subjects were required to respond to each item on a six-point Likert scale in which the categories ranged from very satisfied to very dissatisfied and very important to very unimportant. In order to maximize discrimination (a problem with Likert scales) six response categories were chosen. The instrument thus assessed satisfaction with different domains of life and also their weighted importance to the individual. An overall Q/L index was obtained by simple mathematical extrapolation, providing a score which reflects not only satisfaction but the extent to which an individual values each domain. This approach has been subjected to exhaustive test-retest correlation and possesses content and criterion related validity. Quality of life in QAL Ys. Quality adjusted life years have been determined by questioning 70 ‘healthy’ respondents on their evaluation of physical mobility and freedom from pain (Williams, 1985). These evaluations, coupled with information about life expectancy, have then yielded a meaning for the concept of a QALY. Williams (1985) stated, “The essence of a QALY is that it takes a year of healthy life expectancy to be worth 1, but regards a year of unhealthy life expectancy as worth less than 1. Its precise value is lower, the worse the quality of life of the unhealthy person (which is what the ‘quality adjusted’ bit is all about). If being dead is worth zero, it is, in principle, possible for a QALY to be negative, i.e. for the quality of someone’s life to be judged worse than being dead”. A problem with this concept of a QALY is that it is an extremely impoverished one. As described in the preceding pages, Q/L tests developed for treatment selection, contain many more dimensions than physical mobility and freedom from pain. Consequently, the actual quality of life of patients undertaking these treatments might be very different from those reflected in a calculation which just considers duration, physical mobility and freedom from pain. An assumption inherent in the concept of a QALY, is that it is appropriate to use the evaluations of 70 ‘healthy’ respondents as though this yielded information which is universally applicable. This ignores the individual patient’s own evaluation of his quality of life and undermines his autonomy. It is assumed that the evaluations incorporated in the concept of a QALY have objectivity and are thus universal for all subjects. Although most work in the U.K. has been based on this particular interpretation of a QALY, other

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qualitative dimensions, which are suggested to supplement freedom from pain and physical mobility, would also be subject to the criticism that these evaluations have objectivity and are thus universal for all subjects. In conclusion Q/L measurement is at an early stage of development. Further empirical research is clearly necessary to overcome the shortcomings present in the tests currently used to measure quality of life. The context in which measurements are made. One of the most important aims of measuring Q/L is to evaluate the merits of different treatments and thereby decide what may be the best therapeutic strategies which can be offered to others afflicted with the same disease. Criteria which should inform the decision include the Q/L of post-treatment groups, reflecting it is assumed, the effects of treatment, life expectancy with or without treatment, the physician’s evaluation of the individual’s condition and the autonomous views of the latter. However, a number of intrinsic variables, unique to the individual, may affect Q/L and indeed survival, exclusive of the treatment implemented. Given this, to what extent can we generalize findings from post-treatment to pretreatment groups when making decisions about therapy? To answer this question, which seems not to have been addressed in the literature on Q/L, we must consider which intrinsic factors may affect Q/L or survival and review their implications for the timing of Q/L measurements and the design of research studies. Coping styles or strategies Coping strategies are the behaviours individuals manifest in reponse to life stressors in order to avoid being harmed. The concept refers to any response to a stressor, e.g. an illness, that serves to prevent, avoid or control distress. Pearlin and Schooler (1978) suggest that the resources which enable individuals to develop coping strategies include both psychological personality characteristics and social, interpersonal networks. Of the former, self-esteem, self denigration and mastery-the extent to which one regards one’s life chances as being under autonomous control-are particularly important. Lewis (1982) has shown that experience of personal control over one’s life (as opposed to health), is a significant predictor of Q/L in late stage cancer patients. Individuals appear to cope in different ways, but three broad strategies have been identified. They include: changing the situation which gave rise to the stressor (not possible with a severe, chronic disease); controlling the meaning of the problem by making positive comparisons with other situations or, controlling the stress after it has emerged using denial, avoidance, passive acceptance, fighting or helpless withdrawal. Studies by Greer et al. (1979) and Pettingale (1984) on women who underwent surgery for breast cancer, have shown that a favourable outcome (recurrence free survival) at five and 10 years were related to psychological responses at three months, which were either ‘fighting spirit’ or denial behaviour. A less favourable outcome was associated with helpless/hopeless responses. Exactly what the mechanisms are which explain such an outcome are not known, but the concept that the psychological attitude affects the development and course of cancer via neuroendocrine and immune mechanisms, has been postulated by a number of authors. For example, Levy et al. (1985) investigated natural killer (NK) cell activity, mood, personality and global adjustment to illness in 75 women post-mastectomy at seven days, three months and one year. A low NK cell activity, an index of our immune tumour surveillance system, was associated with apathy, depressed

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psychological responses, and a poor response to treatment. Such findings have clear implications for Q/L studies. This aspect of response to illness must be included in study design as coping permeates all aspects of how an individual responds to depressing symptoms, physical disability, distressing events and survival. Another important point is that developing coping responses may take time, so it is necessary to repeat measurements of Q/L/coping throughout the stages of recovery and relate them to final outcome. Depression Hughes (1985) has shown that depressive illness occurs in a significant number of patients suffering from cancer of the lung after undergoing radiotherapy and that many of these escape medical recognition. The impact which depression can make, especially when measuring Q/L using symptom distress VAS, must always be borne in mind. The presence of anorexia, tiredness and exacerbation of pain, may not be the effects of a particular treatment but the effect of depression. Depression may be rooted in the impact of disease or may, as Hughes emphasizes, be a predisposing factor in certain forms of cancer, for unknown reasons. Placebo effect Cohen (1982) has urged caution in the interpretation of indices of well-being in patients in the initial stages of recovery from surgery due to this well known effect. The postoperative release of anxiety and stress may result in feelings of enhanced well being, regardless of the effects of surgery and bias any Q/L measurements made during that period. Type A personality Rosenmann and Friedmann (1974) categorized the type A personality (coronary prone) as driving, aggressive, time-conscious and work-orientated/work obsessive. After illness those individuals may have a potent drive to return to work, whatever the effects of treatment-this must be considered in relation to Q/L studies after coronary bypass surgery, where resumption of work/patterns or activity are used as outcome criteria. Adaptation Helson’s adaptation theory (Helson and Bevan, 1964) proposes that individuals are continually adapting to new situations, as different stimuli are encountered and their judgements are always made relative to the new adaptation level. For example, sick individuals asked about their Q/L, have a judgement based on an adaptation level influenced by their past and present disease experiences. If severe pain has been experienced in the past, such individuals may judge pain in a new situation as relatively mild, but a person who is well might judge it to be excruciating. This modification of set-points or ‘norms’, makes comparisons between individuals and treatments extremely difficult. De Haes and van Knippenberg (1984) suggest that adaptation explains why, in many studies of Q/L in cancer patients, no differences are found with respect to benign controls and studies of quality of life fail to show what might be expected from clinical experience. Another explanation is that the weighting of different Q/L domains may change as a consequence of treatment, but the overall summation remains the same. Indeed, throughout the ihnesstreatment-recovery trajectory, domains will have to be re-appraised, priorities and goals in life plans will be reviewed and the satisfaction of resignation may be experienced by some, or frustration by others.

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In conclusion, it would seem that we can never measure the impact of treatment/disease in isolation, but only the product of their interaction with an individual whose physiological and psychological responses are unique. Quality of life study designs should incorporate measures of coping and other psychological responses which affect recovery at different stages. All these points illustrate the care that is needed, when extrapolating Q/L findings from a post-treatment group, as a basis for decision making for those about to enter-treatment. Information can be obtained from post-treatment groups for use with pre-treatment groups, but it needs to be viewed critically in the light of all the variables distinguished above. The post-treatment group may have re-appraised domain satisfaction and life goals, or ‘adapted’ to the new situation; the two groups are therefore, not comparable. If we are able to construct meaningful measures of Q/L and assess the impact of treatment, it is surely necessary to obtain serial measurements in health (by recall), throughout the illness and in the phases following treatment before any conclusions are to be drawn about individuals, or indeed, groups.

Conclusions

Within the areas of treatment justification and measurement of the effects of therapeutic intervention, Q/L tests may be devised for two different purposes. The first is to extrapolate from the Q/L tests of previous recipients of treatment or other therapeutic interventions (e.g. nursing) for use with patients whose treatment is under consideration. The second purpose is to devise Q/L tests which are satisfactory for measuring the suitability of a particular patient for any proposed treatment. Whether one test could perform both functions is a question that requires further consideration. Furthermore, this review of the literature suggests that the following criteria must be satisfied by an adequate Q/L test for either of the above uses. (i) It should be subjective in the sense that the information be obtained from the individuals. (ii) Recognition must be given to the fact that the information cannot be abstracted from the individual in isolation from coping strategies, past experiences of illness and other variables. (iii) The Q/L test should incorporate a weighting by the individual, of the importance to them, of the dimensions investigated in the test. (iv) The test should cover a range of dimensions known to contribute to quality of life and include the definition/basis from which it has been developed. (v) It must be designed such that it is appropriate to apply it at different times, to cover the period before the onset of illness, during illness and the different phases which follow treatment. (vi) Further investigation is necessary to establish the influence of adaptation phenomena and coping strategies on quality of life.

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