Patient versus proxy ratings of quality of life

Over the past few decades, the concept of health-related quality of life has evolved as a multi-dimensional and subjective construct that includes a person's physical, psychological, social, and spiritual well-being. With the increasing availability of new and aggressive treatments that can lengthen survival, health-related quality of life is being recognized as an essential outcome in clinical practice and research. Great strides have been made in the development of several generic and disease-specific quality of life measures. While it is generally accepted that health-related quality of life should be directly ascertained from the patient, there are situations where self-report is not a viable option. Population subsets such as very young children, the elderly, patients with severe underlying disease, or those with cognitive disability may not be able to provide information regarding their health status. In such situations, proxiess which include close family members or health care professionals can provide the necessary information on behalf of the patient. The subject of patient-proxy agreement is reviewed in this chapter with a brief consideration of various factors that can influence the level of inter-rater agreement. Specific issues related to the use of proxies are presented for pediatric and adult samples. Finally, the application of proxy assessments of health status in sleep disorders medicine is discussed.