Applications and Issues in Assessment
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meeting of the Association of British Neurologists in April vessels: a direct comparison between intravenous and intra-arterial DSA. 1992. We thank Professor Charles Warlow for his helpful Cl/t Radiol 1991;44:402-5. 6 Caplan LR, Wolpert SM. Angtography in patients with occlusive cerebro- comments. vascular disease: siews of a stroke neurologist and neuroradiologist. AmcincalsouraalofNcearoradiologv 1991-12:593-601. 7 Kretschmer G, Pratschner T, Prager M, Wenzl E, Polterauer P, Schemper M, E'uropean Carotid Surgery Trialists' Collaboration Group. MRC European ct al. Antiplatelet treatment prolongs survival after carotid bifurcation carotid surgerv trial: interim results for symptomatic patients with severe endarterectomv. Analysts of the clinical series followed by a controlled trial. (70-90()',) or tvith mild stenosis (0-299',Y) carotid stenosis. Lantcet 1991 ;337: AstniSuirg 1990;211 :317-22. 1 235-43. 8 Antiplatelet Trialists' Collaboration. 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I: Applications and issues in assessment Ray Fitzpatrick, Astrid Fletcher, Sheila Gore, David Jones, David Spiegelhalter, David Cox Summary Many clinicians remain unsure of the relevance of Box 1: Applications of quality of life measuring quality of life to their clinical practice. measures measures have In health economics quality of life * Screening and monitoring for psychosocial become the standard means of assessing the results problems in individual patient care of health care interventions and, more contro- * versially, the means of prioritising funding; but they Population surveys of perceived health problems have many other applications. This article-the first * Medical audit of three on measuring quality of life-reviews the * Outcome measures in health services or evaluation instruments available and their application in research screening programmes, audit, health care research, * Clinical trials and clinical trials. Using the appropriate instrument * Cost-utility analyses is essential if outcome measures are to be valid and clinically meaningful. patients' judgments of quality of life differ substantially Interest in measuring quality of life in relation to and systematic assessment may improve health profes- health care has increased in recent years.' 2 The sionals' judgments.':1 Clinicians seem to find the Department ofPublic information from quality of life measures useful and Health and Primary Care, purpose is to provide more accurate assessments of University ofOxford, individuals' or populations' health and of the benefits informative but trials have found that the additional Nuffield College, Oxford and harm that may result from health care. The term information does not greatly alter clinical decisions OXI 1NF quality of life misleadingly suggests an abstract and or short term changes in health status.7 These Ray Fitzpatrick, itniversitV philosophical approach, but most approaches used in disappointing results may arise either because the lectu.rer in medical sociology medical contexts do not attempt to include more quality of life data are inappropriate to clinical decision general notions such as life satisfaction or living making or, more likely, because the information is not Royal Postgraduate standards and tend rather to concentrate on aspects of fed back to clinicians in the most useful format or at the Medical School, London personal experience that might be related to health and right time. W12 OHS Quality of life measures used for screening need to Astrid Fletcher, senior health care. Some of the commonly used synonyms for lecturer int epidemiology quality of life more accurately convey the content and be evaluated in terms of sensitivity (false negative purpose of measures-health related quality of life, results) and specificity (false positive results). Instru- Departnment of subjective health status, functional status. This is the ments whose value has been proved for screening Epidemiology and Public first of three papers intended to review measurement should not be assumed to be effective for other Health, University of issues surrounding the use of the growing number of purposes-for example, as outcome measures in trials Leicester, Leicester questionnaires and interview based instruments or in evaluation studies. A recent conference on David Jones, professor of designed to assess health related quality of life. applications of quality of life instruments in routine medical statistics patient care concluded that, in the United States at least, many practitioners have a mixture of enthusiasm Medical Research Council Alternative applications Biostatistics Unit, for their potential relevance to clinical practice and Cambridge CB2 2SR Quality of life measures can be used in many ways in unresolved doubts.' Sheila Gore, seniior statistician health care (box 1). For example, quality of life David Spiegelhalter, senior instruments have been shown to be better than conven- POPULATION APPLICATIONS statistician tional rheumatological measures as predictors of long Quality of life instruments can also be used in term outcomes in rheumatoid arthritis in terms of both surveys of the health of district or general practice Nuffield College, Oxford morbidity and mortality.' They can therefore be used populations. Such instruments can assess subjective OXI 1NF to identify patients needing particular attention. They aspects of health problems not addressed by conven- David Cox, wardeni may also be used to screen for psychosocial problems; tional epidemiological measures."' Here too, how- it is not clear how Correspondence to: to monitor patients' progress, pa'rticularly in relation to ever, yet useful quality of life Dr Fitzpatrick. the management of chronic illness; or to determine information will prove in assessing health needs." choice of treatment. In more formal studies of health service research BAl1 992;305:1074-7 Several studies have shown that clinicians' and quality of life assessments provide an important 1074 BMJ VOILUME 305 31 OCTOBER 1992 outcome measure.'2 Increasingly it is argued that wellbeing or sense of social support. This diversity of quality of life measures should be incorporated in experience cannot be captured in a single scale. medical audit.'3 Certainly, they provide information There are two basic types of instrument, disease that is relatively economical to gather and process for specific and generic. Disease specific instruments have audit purposes. Unlike much audit data, quality of life been developed for one disease or a narrow range of focuses on outcomes and patients' concems. One ofthe diseases. Examples include the arthritis impact few studies in Britain to examine the application of measurement scales2' and the back pain disability quality of life data to regular hospital medical audit questionnaire.22 Generic instruments are intended to gave encouraging results. A demonstration project at be applicable to a wide range of health problems. the Freeman Hospital, Newcastle, was successful in Among the more commonly used are the sickness setting up a routine systemto collect outcome measures impact profile23 and the Nottingham health profile.24 including quality of life assessments in a way that was For cancer modular format instruments have recently acceptable to clinicians and managers." The feasibility been developed, which comprise a core of general of routine use of quality of life instruments has also purpose quality of life items together with more been shown in several health care settings in the United specific instruments designed for each of the main States, although these studies suggest that consider- types of cancer.2 able attention has to be given to integrating data Though some instruments are administered by gathering into clinic and surgery routines and making clinicians or interviewers, increasingly the emphasis data readily intelligible to busy clinicians.'3 '6 has been on self completed questionnaires for each and economy of use. The quantitative information pro- vided also varies. Most give scores for the different Clinical trials dimensions of quality of life which are not intended to The best understood application of quality of life be combined but others assess dimensions that may be measures