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INTRODUCTIONHealth-related quality of life (HRQL) measures have been widely used inhealth research in recent years and have been the endpoint in many clinicalstudies. This trend reflects the recognition that many treatments for chronicdiseases fail to provide a cure and that the benefits of therapy may be limited.In some circumstances, the clinical therapeutic benefits may be outweighedby HRQL considerations. In addition, patients are interested in knowing theeffect of a therapy on their HRQL. Patient advocacy groups have called forprovision of comprehensive information about the consequences of the diseaseand treatment on the daily lives of patients. Funding bodies, agencies and ethicsreview committees have also become interested in HRQL assessments andhave encouraged the use of HRQL measures in clinical studies.Nonetheless incorporating HRQL assessments into clinical research representa challenge. This monograph provides an overview of HRQL measurementto facilitate an understanding of HRQL measures to be used in both clinicalpractice and research. Clinicians of all disciplines may find this monographuseful in guiding their selection of HRQL measures for use in their clinicalpractice and research programs. The monograph also provides a brief summaryof HRQL studies conducted at the Institute of Health Economics.HISTORYIn contemporary society most people are familiar with the term “Qualityof Life”. However, it may have different meanings to different people. Is ithappiness? Is it absence of disease? Is it satisfaction with life?For many years attempts have been made to define Quality of Life (QoL).Probably one of the first definitions of QoL appears in the NichomacheanEthics. Aristotle (384–322 BC) described QoL as both a state of feeling and akind of activity. He incorporated the idea of “being happy” and physical activityinto the definition of QoL. He also noted that QoL meant different things todifferent people and that it varied according to a person’s current situation.For example, the same man says different things at different times: “when hefalls sick he thinks health is happiness, when he is poor, wealth” (Fayers P. andMachin D. 2000, pg 5).Despite the numerous uses of the term QoL, the concept was not measureduntil the twentieth century. The earliest attempts to assess functional healthstatus in adults, as the ability to perform self-care and basic physical activities,was published in 1937 (Prutkin JM 2002). Ten years later, David Karnofskydeveloped a scale to evaluate the performance status of cancer patients inclinical settings. This scale ranges from 0 (dead) to 100 (normal, no complaints,no evidence of disease). The Karnofsky scale led to the development of TheIndex of Independence of Activities of Daily Living (Katz et al 1963) and the1The Importance of Measuring Health-related Quality of Life
Barthel Index (Mahoney and Barthel 1965). In 1957, the PULSES profile waspublished (Moskowitz and McCann). It was derived from a profile developedby the Canadian army to assess the functional status of new soldiers duringWorld War II. PULSES was probably the first functional status index toinclude mental and emotional status. Over the next two decades numerousQoL measures were developed including the Eastern Cooperative CancerChemotherapy Group in 1960 (Oken et al.1982) and the Sickness ImpactProfile in the 1970’s (Bergner et al 1981).QoL measures include different aspects of people’s perceptions about health.Some of the measures assessed the physical and emotional aspects, othersexamined the effects of treatment or disease, such as fatigue. Others adopteda holistic approach by including people’s beliefs.Parallel to these different approaches to measuring QoL are a variety oftheoretical models (Fayers and Machin (2000)). The “expectations model”(Calman 1984) measures QoL as the difference between the hopes andexpectations of the individual and their current status/experience. This modelmay be related to a previous theory by Freud (1917) where he referred to“the gap” between the real self and the ideal self when assessing individualswith depression. The “needs model” describes QoL at its highest when allneeds are met and at its lowest when few needs are satisfied. Aspects such asidentity, self-esteem, affection, love, food, sleep, pain avoidance and activitywere considered as “needs”. The “existential approach” recognized by Aristotleincludes items such as pleasure in life and positive outlook. This model isimportant when assessing QoL in patients whose perceptions are influenced byexistential beliefs. The patient-preference utility model focuses on the value thatsubjects attach to various health status. Would you rather live with a chronicdisease for the rest of your life or would you prefer immediate death? Whenafter an accident the surgeon suggests a procedure with a 50:50 chance to die,would the patient take the risk? What is the patient’s preference? This modelis derived from utility and decision-making theory and is particularly useful ineconomic evaluation of healthcare services.To this point we had an idea of the historical development of the measures ofQoL, but what is “Health”? What is health-related quality of life (HRQL)? Whymeasure HRQL?DEFINITIONSWhat is Health?The World Health Organization defines health as “a state of completephysical and mental and social well-being, and not merely the absenceof disease or infirmity (Official Records of the World Health Organization,no. 2, p. 100 1948).The Importance of Measuring Health-related Quality of Life 2
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Page 4 and 5: ACKNOWLEDGMENTSThe authors acknowle
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Page 10 and 11: Reliability: A measure is reliable
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Page 14 and 15: Edelman et al. (1999) compared HUI2
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Page 22 and 23: Table 1. Summary Information on HRQ
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