The following article appeared in Quality of Life Newsletter, No. 22, May-August, 1999, pages 8 - 9. MAPI Research Institute, Lyon, France and is used here with their kind permission.
The Health Utilities Index: An
As many readers of Quality of Life Newsletter know the Health Utilities Index (HUI) is a family of generic health status and health-related quality of life (HRQL) measures. The family of measures includes the Health Utilities Index Mark 1 (HUI1), Mark 2 (HUI2), and Mark 3 (HUI3) systems. Each HUI measure includes a health-status classification system and a preference-based scoring formula. Although HUI1 is still used, HUI2 and HUI3 are much more frequently used both in clinical and population health studies and will be the focus of this note.
Applications of HUI require that data be collected to classify the health status of each subject at a point in time. A variety of health status questionnaires and related procedure manuals are available to facilitate the application of HUI systems. HUI has been applied by hundreds of researchers around the world.
Basic Description. HUI2 consists of seven attributes (or dimensions) of health status with three to five levels per attribute. (Detailed descriptions of HUI can be found in Feeny et al. 1995, 1996.) The levels range from highly impaired to normal. The comprehensive health state of a subject is described as a seven-element vector, one level for each attribute. The attributes in HUI2 are sensation (vision, hearing, speech), mobility, emotion, cognition, self-care, pain, and fertility. (HUI2 was initially developed to assess outcomes among survivors of cancer in childhood. Infertility and sub-fertility are sequelae of some childhood cancers.) A multiplicative multi-attribute utility function for HUI2 translates the categorical data on health status into interval-scale single-attribute utility scores (reflecting the morbidity in that dimension of health status) and overall HRQL utility scores reflecting global HRQL (Torrance et al. 1995, 1996).
HUI3 was originally developed for the 1990 Statistics Canada Ontario Health Survey. HUI3 has eight attributes (vision, hearing, speech, ambulation, dexterity, emotion, cognition, and pain) with five to six levels per attribute. A multiplicative multi-attribute utility function and single-attribute utility functions for HUI3 have been released recently (Furlong et al. 1998).
Standardized HUI2/HUI3 Questionnaires. Questionnaires which provide sufficient information to describe the health status of a subject at a point in time in both the HUI2 and HUI3 systems have been developed. These are available in a variety of formats.
Recall Period. Standard recall periods are one week, two weeks, four weeks, and usual health (often used in long term follow-up studies and general population surveys). Customized applications such as the “previous 24 hours” have been developed to meet the needs of particular studies (for instance, peri-operative period in a surgery trial).
Mode of Administration. Self-complete and interviewer-administered versions are available.
Viewpoint. Self assessment and proxy assessment formats are available. Proxy respondents are particularly useful when patients are too young to respond on their own behalf or when their health condition attenuates the ability of subjects to provide reliable responses (Alzheimer Disease).
Algorithms. For each of the standard mode of administration formats (self-complete, interviewer-administered), there are standardized algorithms for converting responses on questionnaires into levels in the HUI2 and HUI3 systems. The use of standardized algorithms enhances the comparability of HUI data across studies. These algorithms have been extensively tested and are well documented.
Languages. The complete family of questionnaires (n = 16) is available in Canadian English. High quality translations are available for many selected formats in French Canadian and a limited number of formats in other languages including Dutch, French, German, and Spanish. In other cases prototype translations are available. Languages into which HUI2/3 materials have been translated include Chinese (Mandarin), Danish, Dutch, Finnish, Flemish, French, German, Japanese, Malay, Norwegian, Spanish, and Swedish. Work on Portuguese and Italian translations is underway.
Why Use both HUI2 and HUI3? There is some overlap between HUI2 and HUI3. Yet, in other ways, the two systems complement each other. For instance, the concepts of emotion differ between the two systems; HUI2 refers to worry and anxiety while HUI3 to happiness versus depression. Similarly the concepts of pain differ; while both refer to the degree of severity of the pain, HUI2 focuses on the use of analgesia while HUI3 focuses on the disruption of activities. Self-care and fertility are available only in HUI2; dexterity is available only in HUI3. HUI2 has been extensively used in clinical studies, providing useful benchmark results for comparisons. HUI3 has been used in four major Canadian population health surveys, providing extensive data on population norms. Thus, in practice in clinical studies the two complement each other in major ways.
HUI3 Scoring Function. With the recent release of a multiplicative multi-attribute utility function for the HUI3 system, users are now able to generate utility scores for HUI3 health states. The HUI3 scoring function is based on preference measurements obtained from a random sample of the general population (?16 years of age) in Hamilton, Ontario, Canada. The performance of the HUI3 scoring function has been assessed extensively (see Furlong et al. 1998). For instance, the intra-class correlation coefficient between scores generated by the HUI3 scoring function and directly measured scores obtained in a separate preference survey (“out of sample”) that was conducted parallel to the survey used to estimate the HUI3 function was 0.88 (Furlong et al. 1998). Thus, there was a high level of agreement between directly measured utility scores for HUI3 health states and scores obtained using the multiplicative function.
HUI Study Groups. HUI was developed in Canada at McMaster University. Groups of researchers in other countries have formed to translate and culturally adapt HUI, and to assess the measurement properties of the adapted instrument in their setting. Several groups are also engaged in studies to estimate multi-attribute utility functions in their own countries. Countries in which there are active HUI Groups include Austria, France, Japan, the Netherlands, Singapore, and the United Kingdom.
The Future. There are a number of ongoing studies that will provide further evidence on reliability, responsiveness, and construct validity of HUI2 and HUI3 in particular settings. Evidence on the cross-sectional and longitudinal construct validity of HUI in a variety of clinical and population health settings continues to accumulate. In some applications, special disease-specific modules have been added to HUI to enhance its descriptive power. (The additional detail on health status is not, however, incorporated into the utility scores.) These disease (or problem) specific modules need to be carefully developed and assessed. Nonetheless, such modules have the potential to combine the advantages of the focus of specific measures and the generalizability of generic measures. There is also ongoing work assessing the performance of the multiplicative HUI2 and HUI3 scoring functions. For instance, in one study directly measured utility scores for the subjectively-defined current health state of subjects and the HUI2 and HUI3 scores for their current health are being compared. Work is also underway comparing the performances of several multi-linear utility functions for the HUI3 system and the multiplicative HUI3 function.
Inquiries. Further information on HUI; a list of references on HUI; applications for the use of copyrighted HUI questionnaires, algorithms, and supporting materials; and a price list for HUI services can be obtained from:
Telephone: (905) 525-9140, extension
Feeny, David H., George W. Torrance, and William J. Furlong, "Health Utilities Index," Chapter 26 In Bert Spilker, ed. Quality of Life and Pharmacoeconomics in Clinical Trials. Second Edition. Philadelphia: Lippincott-Raven Press, 1996, pp 239-252.
Furlong, William, David Feeny, George
W. Torrance, Charles Goldsmith, Sonja DePauw, Michael Boyle, Margaret Denton,
and Zenglong Zhu, “Multiplicative Multi-Attribute Utility Function for
the Health Utilities Index Mark 3 (HUI3) System: A Technical Report,” McMaster
University Centre for Health Economics and Policy Analysis Working Paper
No. 98-11. (To view the 98-11 abstract, click on the "CHEPA Paper 98-11" navigation button)
Torrance, George W., William Furlong, David Feeny, and Michael Boyle, "Multi-Attribute Preference Functions: Health Utilities Index." PharmacoEconomics, Vol 7, No 6, June, 1995, pp 503-520.
Torrance, George W., David H. Feeny,
William J. Furlong, Ronald D. Barr, Yueming Zhang, and Qinan Wang, "Multi-Attribute
Preference Functions for A Comprehensive Health Status Classification System:
Health Utilities Index Mark 2." Medical Care, Vol. 34, No. 7, July 1996,
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