RE: Hinds et al. The Health Utilities Index 3 Invalidated. Cancer Nursing. 2007;30(3):169Y177. David Feeny, PhD, William J. Furlong, MSc, Ronald D. Barr, MD, MBChB To the Editor: These investigators have identified a high prevalence of missing data when pediatric oncology nurses were asked to complete health status questionnaires as proxy respondents for children undergoing therapy for acute lymphoblastic leukemia (ALL). These results, based on assessments of 122 patients at 2 institutions, raise important issues and warrant further discussion. The questionnaire used in the study was the interviewer- administered version of the Health Utilities Index Mark 2 (HUI2) and Health Utilities Index Mark 3 (HUI3) questionnaire. 1,2 Four important issues are raised by these investigatorsVthe extent to which nurses are knowledgeable about the current health status of patients, the extent to which nurses solicited information from patients and their parents to inform their responses, the roles of generic and specific measures of health status and health-related quality of life (HRQL), and whether the format of the questionnaire used in the study was appropriately matched to the method of data collection. We will discuss each issue in turn. Clinical investigators are interested in obtaining information on health status and HRQL from the patients themselves. However, both for practical and more fundamental reasons, investigators may also be interested in proxy assessments provided by family members and/or clinicians. In many clinical situations, there are multiple versions of ‘‘truth’’Vmultiple valid viewpoints. Patients may have deeper insight into subjective dimensions of health status, such as their emotional state. Family members may see a patient in a variety of contexts and thus have the opportunity to form well-informed impressions of how well the patient is or is not functioning. By virtue of the clinicians’ training and experience, they may be better able to distinguish normal from abnormal functioning. Thus, in many situations in pediatrics, it makes sense to include both self-assessment and proxy assessment by family members and clinicians in a study to provide comprehensive information on health status and HRQL. These arguments about the potential usefulness of proxy assessments are, however, predicated on the assumption that the proxy assessor has adequate familiarity with the health status of the patient. Perhaps the design of the study by Hinds et al artificially limited the ability of the nurses to obtain information from patients and parents. In pediatric settings, it is common for clinicians to ask patients and their parents about various aspects of the child’s health, including physical functioning, emotional state, and pain and discomfort. Hinds et al indicate that information was often missing for 5 of the 8 dimensions of health status included in the HUI3 system: vision, ambulation, emotion, cognition, and pain. Vision is seldom affected by ALL and its treatment, so nurses would have had little clinical motivation to obtain information on visual function. Emotion and pain are relatively subjective and might be expected to change over the course of therapy. For these attributes, there may be no substitute for obtaining information from patients and/or parents. Ambulation is observable, especially in out- patient clinic settings. Perhaps cognition lies somewhere between the observability of ambulation and the Authors’ Affiliations: The Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon; University of Alberta and Institute of Health Economics, Edmonton, Alberta, Canada (Dr Feeny); Health Utilities Incorporated, Dundas, Ontario, Canada (Dr Feeny and Mr Furlong); Centre for Health Economics and Policy Analysis and Department of Clinical Epidemiology and Biostatistics (Mr Furlong), Department of Pediatrics (Dr Barr), McMaster University, Hamilton, Ontario, Canada; and McMaster Children’s Hospital of Hamilton Health Sciences Corpo- ration, Hamilton, Ontario, Canada (Dr Barr). Conflict of Interest: It should be noted that David Feeny and William Furlong have a proprietary interest in Health Utilities Incorporated, Dundas, Ontario, Canada. Health Utilities Inc distributes copyrighted Health Utilities Index materials and provides methodological advice on the use of Health Utilities Index. Corresponding author: David Feeny, PhD, Center for Health Research, Kaiser Permanente Northwest, 3800 N Interstate Ave, Portland, OR 97227- 1110 (David.Feeny@kpchr.org). Letter to the Editor Cancer Nursing TM , Vol. 31, No. 4, 2008 n 261 etter to the Editor L Copyright @ 2008 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.