HEALTH-RELATED QUALITY-OF-LIFE ASSESSMENT IN MEDICAL-CARE - FOREWORD

The concept of assessing health-related quality of life has a brief an d vibrant history. In this monograph, theoretical issues related to th e term and the reasons assessment of quality of life is important are discussed. There is a great deal of ambiguity surrounding definitions of the concept. This equivocation is caused in part by the fact that t hinking on both the concept of health-related quality-of-life assessme nt and the way in which it should be measured are still evolving. Meth odologic concerns regarding the assessment of health-related quality o f life are discussed, including ways in which the validity and reliabi lity of measurement approaches are established. These characteristics are important because they are necessary to ensure that accurate infor mation is obtained with whatever instrument or procedure is used. Many significant issues relate to the use of quality-of-life assessment, a nd these are delineated. Consideration and resolution of these issues are prerequisites to the introduction of a given assessment instrument or procedure into a study. A large section of this article is devoted to a review of selected measures of health-related quality of life. T hree types of measures are discussed. The first type is referred to as general. These measures are designed to be used across different dise ases, different treatments or interventional and different groups of p atients. The reliability and validity of general instruments or proced ures, plus their history of empirical use, make them invaluable method s of measurement. The second type of measure is referred to as disease specific. These measures are designed to assess specific diagnostic o r patient populations with the goal of detecting responsiveness or cli nically significant changes. The ability to assess such changes in a p articular patient population has led to major growth in the developmen t and introduction of these instruments in the past few years. The fin al type of measure consists of batteries of separate instruments that are scored independently. The advantage of using this approach is that the battery can be put together to assess whatever aspects of health- related quality of life need to be measured. Examples of quality-of-li fe assessment in medical research include a discussion of how various procedures are used to measure the construct with asthma, chronic resp iratory disorders, and human immunodeficiency virus (HIV) disease. All three types of assessment-general, disease specific, and batteries of measures-have been used in this respect. Newer methods of assessment, particularly disease-specific instruments and procedures, are also de scribed. General recommendations are offered to clinicians who may wis h to include quality-of-life assessment in their research. This articl e concludes with a description of trends observed in quality-of-life a ssessment. We note that although no single gold-standard measure is ap t to emerge for assessing quality of life, some general instruments ar e gaining wide acceptance. In addition, the proliferation of disease-s pecific instruments is noted. Finally, we discuss evidence that two tr ends-linking quality of life to economic indices and to the developmen t of more complex models of assessment-will continue to expand both th e arsenal and the application of health-related quality-of-life measur es.