The Health Utilities Index (HUI) system for assessing health-related quality of life in clinical studies.

This paper reviews the Health Utilities Index (HUI) systems as means to describe health status and obtain utility scores reflecting health-related quality of life (HRQoL). The HUI Mark 2 (HUI2) and Mark 3 (HUI3) classification and scoring systems are described. The methods used to estimate multiattribute utility functions for HUI2 and HUI3 are reviewed. The use of HUI in clinical studies for a wide variety of conditions in a large number of countries is illustrated. HUI provides a comprehensive description of the health status of subjects in clinical studies. HUI has been shown to be a reliable, responsive and valid measure in a wide variety of clinical studies. Utility scores provide an overall assessment of the HRQoL of patients. Utility scores are also useful in cost-utility analyses and related studies. General population norm data are available. The widespread use of HUI facilitates the interpretation of results and permits comparisons. HUI is a useful tool for assessing health status and HRQoL in clinical studies.

The role of permanent income and family structure in the determination of child health in Canada.

We use data from the Ontario Child Health Study (OCHS) to provide the first Canadian estimates of how the empirical association between child health and both low-income and family status (lone-mother versus two-parent) changes when we re-estimate the model with pooled data. Two waves of data provide a better indication of the family's long-run level of economic resources than does one wave. Our measures of health status include categorical indicators and the health utility score derived from the Health Utilities Index Mark 2 (HUI2) system. Consistent with findings from other countries, we find that most outcomes are more strongly related to low-average income (in 1982 and 1986) than to low-current income in either year. Unlike some previous research, we find the quantitative impact of low-income on child health to be modest to large. Lone-mother status is negatively associated with most outcomes, but the lone-mother coefficients did not change significantly when we switched from low-current income to low-average income. This implies that the lone-mother coefficient in single cross-sections is not just a proxy for low-permanent income.

Health-related quality of life in survivors of tumours of the central nervous system in childhood--a preference-based approach to measurement in a cross-sectional study.

There is an evident need to measure the comprehensive burden of morbidity experienced by survivors of brain tumours in childhood. To this end, a questionnaire based on the Health Utilities Index mark 2 (HUI2) and mark 3 (HUI3) systems was completed independently for a cohort of such children by their parents, by a nurse, by physicians and by a selected group of the children themselves. Each of the HUI2 and HUI3 systems consists of a multi-attribute health status classification scheme linked to a preference function which provides utility scores for levels within single attributes (domains of health) and for global health states. All eligible families (n = 44) participated. Even cognitively impaired children of at least 9.5 years of age could complete the questionnaire. The greatest burden of morbidity, occurring in two-thirds of children, was in the attribute of cognition. Surprisingly, almost one-third of children experienced pain. Global health status was lowest in children who underwent radiotherapy before the age of 5 years and the corresponding utility scores were related inversely to the volume irradiated. Children with demonstrable disease had lower scores than those in whom disease was not evident. There was a high level of agreement (intraclass correlation coefficients > 0.5) on formal assessment of inter-rater reliability for global health-related quality of life utility scores. The usefulness of measures of health status and health-related quality of life, in children surviving brain tumours, has been demonstrated by this study.

Applicability of the Health Utilities Index to a population of childhood survivors of central nervous system tumours in the U.K.

This paper describes the application of a multi-attribute, preference-linked health status and health-related quality of life measurement system--the Health Utilities Index (developed in Canada)--to a group of subjects in the U.K. Children who had survived tumours of the central nervous system (n = 30, age 6-16 years) formed the study group. Respondents (children, parents, physicians and physiotherapists) found the activity (completion of a 15-item questionnaire) to be acceptable and not burdensome (it was accomplished easily by all children > or = 10 years of age). Instrumental reliability was established by acceptable intra- and interobserver agreement and construct validity was supported by strong similarities between the results obtained in this study and those reported from a similar group of children in Canada. The greatest burden of morbidity was reported for the attributes of emotion and cognition (each affected in > 50% of the children). Pain was surprisingly prevalent (affected in approximately one-third of children). The finding of a large number of unique health states emphasises the complex morbidity burden experienced by these children who self-reported poorer overall health (as reflected in utility scores) than did the proxy respondents. The information obtained from this study is readily interpretable and clinically useful. The results of this study also illustrate that extreme caution must be exercised in undertaking linguistic modifications to established instruments for, in this instance, these resulted in a loss of the ability to detect the most severe emotional morbidity and reduced the comparability of results between studies. With this provision, the Health Utilities Index is evidently applicable in the U.K. and the original version has been recommended for use in brain tumour studies by the U.K. CCSG (the U.K. Children's Cancer Study Group).

Generic and specific measurement of health-related quality of life in a clinical trial of respiratory rehabilitation.

The purpose of this study was to compare the performance of measures of health-related quality of life in a randomized controlled trial of respiratory rehabilitation versus conventional community care for patients with chronic airflow limitation. The study included 89 stable patients with moderate to severe chronic airflow limitation with measurement of health status at 12, 18, and 24 weeks. Outcomes included two disease-specific (the Oxygen Cost Diagram and the Chronic Respiratory Questionnaire [CRQ]) measures, a generic health profile (the Sickness Impact Profile [SIP]), and two utility measures (the Standard Gamble and the Quality of Well-Being index [QWB]). Of the measures, only the four domains of the CRQ (dyspnea, fatigue, mastery, and emotional function) showed statistically significant differences (P < or = 0.05) between treatment and control groups. Correlation between change in the CRQ and change in other relevant measures, including the 6-minute walk test and global ratings of change in dyspnea, fatigue, and emotional function were generally weak to moderate (from 0.19 to 0.51). All correlations between change in the QWB, SIP, and Standard Gamble and other measures were very weak or weak (up to 0.30). Correlation between change in the three generic measures were all very weak (<0.15). The results suggest that unless investigators include responsive and valid disease-specific measures of health-related quality of life in controlled trials in chronic diseases, they risk misleading conclusions about the effect of treatments on health status.

Mutual concurrent validity of the child health questionnaire and the health utilities index: an exploratory analysis using survivors of childhood cancer.

Mutual concurrent validity of 2 generic measures of health-related quality of life (HRQL), the Child Health Questionnaire (CHQ) and the Health Utilities Index Mark 2 (HUI2) and HUI3, was assessed. Data were from 3 centers participating in a Canadian multi-center retrospective cohort study currently in progress to assess psycho-social and physical late effects in children surviving >/=5 years after cancer diagnosis between 1981 and 1990. Exploratory results are from 244 parent reports on HRQL in children <16 years old when studied. Spearman rank-order correlations between sub-scale scores for the CHQ and single-attribute utility scores for the corresponding attribute from the HUI2 and HUI3 were used. As predicted, the correlation between CHQ bodily pain and HUI2 and HUI3 pain was strong, 0.58 and 0.60, respectively, while correlations between CHQ physical functioning and HUI2 mobility and HUI3 ambulation were moderate, both 0.45. Correlations between CHQ mental health and HUI2 and HUI3 emotion were strong, 0.64 and 0.54, respectively, rather than moderate, as predicted. Both the CHQ general health scale and the general health single item were moderately correlated with the HUI2 and HUI3 global utility scores rather than weakly, as predicted (CHQ general health scale and HUI2 and HUI3 global utility were 0.43 and 0.44, respectively; CHQ general health single item and HUI2 and HUI3 global utility were 0. 38 and 0.42, respectively). The CHQ and HUI, which are based on different methodologies (summative Likert scaling and utility analysis, respectively), appear to capture similar constructs in childhood cancer survivors.

Preliminary translation and cultural adaptation of Health Utilities Index questionnaires for application in Argentina.

Quality-of-life assessment is being used increasingly in clinical research. This is true particularly in the case of survivors of cancer in childhood, where improving survival rates have raised concern regarding the long-term effects of medical cure. Health-status assessment and quality-of-life instruments have been developed for the most part in the English language, thus necessitating their translation and cultural adaptation for use in non-English-speaking countries. Our purpose was to develop a set of Spanish-language questionnaires for application with a population of children with cancer in a tertiary-care center in Buenos Aires, Argentina. The Health Utilities Index (HUI), a conceptual framework for assessing health status, was chosen for this study. Three distinct questionnaires, based on the HUI, were used: a self-completed one for health professionals and teachers (15Q) to report assessments of children and 2 interviewer-administered ones, for child survivors (42Q) to report assessments about their own health status and parents (45Q) to report assessments about their children's health status. The original translations and reviews were accomplished with direct oversight by members of the HUI Group, to ensure conceptual equivalence. The instruments were then tested in Buenos Aires by application to staff of the hematology-oncology service, childhood cancer patients and the parents of childhood cancer patients. Several modifications were made based on these tests. We concluded that the translation and cultural adaptation of these instruments was adequate for use with the groups tested in a pilot survey of survivors of childhood cancer in Argentina.

Minimum skills required by children to complete health-related quality of life instruments for asthma: comparison of measurement properties.

To gain a complete picture of a child's health-status, measurement of health-related quality of life (HRQL) is necessary. Since parents do not accurately perceive children's HRQL, information must be obtained from the children themselves. The aim of this study was to determine the minimum age and reading skills required by children to complete competently the Paediatric Asthma Quality of Life Questionnaire (PAQLQ), the Health Utilities Index (HUI), the Feeling Thermometer and the Standard Gamble, and to evaluate the validity of each for measuring HRQL in children with asthma. Fifty two children (age 7-17 yrs) with symptomatic asthma participated in a 9 week single cohort study with HRQL and clinical asthma control assessed every 4 weeks. All children provided very reliable data for the PAQLQ and the HUI but they needed > or = grade 6 reading skills to complete the Standard Gamble and > or = grade 2 skills for the Feeling Thermometer. In those children who were able to provide reliable data, the PAQLQ had the best discriminative and evaluative measurement properties, followed closely by the Feeling Thermometer. Measurement properties in the Standard Gamble were weaker and although the HUI was very reliable it was not actually measuring asthma-specific HRQL. The Paediatric Asthma Quality of Life Questionnaire may be used with confidence in clinical studies and practice to provide a profile of children's day-to-day experiences. In those children with adequate skills to complete the test reliably, the Feeling Thermometer provides a good estimate of the value that children place on their asthma health status.

Does it matter whom and how you ask? inter- and intra-rater agreement in the Ontario Health Survey.

A large amount of information in the 1990 Ontario Health Survey (OHS) was collected from proxy respondents using questions administered in face-to-face interviews. Can this type of information represent candid self-reported measures of health status? Inter-rater agreement was assessed using Cohen's kappa statistic for responses to questions that were answered both by individuals about themselves and by proxies on their behalf. Intra-rater agreement, assessing the effect of mode of survey administration (in-person interviews versus self-completed written questionnaires) on the responses, was also investigated using the kappa statistic. We conclude that: (1) proxy responses in the OHS for impairments of emotion and pain are not reliable indicators of self-response (kappa < 0.32) because proxy respondents consistently under-report the burden of morbidity; (2) levels of morbidity reported by subjects to interviewer-administered questionnaires may underestimate morbidity, relative to morbidity reported by subjects using self-administered questionnaires completed in privacy. We also hypothesize that the relative magnitudes of inaccuracy introduced by interviewer administration relative to proxy reporting depends on the phenomenon being measured. When assessing pain, mode of administration is quantitatively a more important source of disagreement than type of respondent.

Children and adult perceptions of childhood asthma.

OBJECTIVE: To explore children's and parents' assessment of children's asthma. DESIGN: Prospective 2-month cohort study in which children and parents were reviewed at baseline and 1-month intervals. SETTING: Mid-sized, English-speaking, industrial community serving an urban and regional rural population. PATIENTS OR PARTICIPANTS: Fifty-two children, 7 to 17 years old, with a wide range of asthma severity, and their parents. INTERVENTIONS: We offered patients with inadequately controlled asthma additional inhaled steroid. MAIN OUTCOME MEASURES: Children and parents provided global ratings of change in childhood symptoms and children completed spirometry and the Paediatric Asthma Quality of Life Questionnaire at clinic visits. Patients recorded peak flow rates, symptoms, and medication use in a daily diary. The diary symptom report, medication use, and spirometry were combined to form an asthma control score. RESULTS: In children younger than 11, children's global rating of change in symptoms correlated strongly with changes in quality of life (0.54 to .67) but not with measures of airway caliber or asthma control, while parents' global ratings did not correlate with children's quality of life but showed moderate correlations with airway caliber (0.29 to .48) and asthma control (0.50). In children over the age of 11, correlations with all clinical variables were higher for their own than their parents' global ratings. CONCLUSIONS: In children under 11, clinicians can gain complementary information from questioning children and parents. For children over 11, parents can provide little if any information beyond that obtained through questioning the child.

Multiattribute utility function for a comprehensive health status classification system. Health Utilities Index Mark 2.

The Health Utilities Index Mark 2 (HUI:2) is a generic multiattribute, preference-based system for assessing health-related quality of life. Health Utilities Index Mark 2 consists of two components: a seven-attribute health status classification system and a scoring formula. The seven attributes are sensation, mobility, emotion, cognition, self-care, pain, and fertility. A random sample of general population parents were interviewed to determine cardinal preferences for the health states in the system. The health states were defined as lasting for a 60-year lifetime, starting at age 10. Values were measured using visual analogue scaling. Utilities were measured using a standard gamble technique. A scoring formula is provided, based on a multiplicative multiattribute utility function from the responses of 194 subjects. The utility scores are death-anchored (death = 0.0) and form an interval scale. Health Utilities Index Mark 2 and its utility scores can be useful to other researchers in a wide variety of settings who wish to document health status and assign preference scores.

Measuring quality of life in the parents of children with asthma.

Parents and primary caregivers of children with asthma are limited in normal daily activities and experience anxieties and fears due to the child's illness. We have developed the Paediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ) to measure these impairments. The objective of this study was to evaluate the measurement properties of the PACQLQ. A 9-week single cohort study was conducted with assessments at 1, 5 and 9 weeks. Participants in the study were primary caregivers of 52 children (age 7-17 years) with symptomatic asthma, recruited from notices in the local media and paediatric asthma clinics. Caregivers completed the PACQLQ, Impact-on-Family Scale and Global Rating of Change Questionnaires. Patients completed the Paediatric Asthma Quality of Life Questionnaire and an asthma control questionnaire. Spirometry and beta-agonist use were recorded. The PACQLQ was able to detect quality of life changes in those caregivers who changed (p < 0.001) and to differentiate these from the caregivers whose quality of life remained stable (p < 0.0001). The PACQLQ is reproducible in subjects who are stable (ICC = 0.84), and showed acceptable levels of longitudinal and cross-sectional correlations with the child's asthma status and health-related quality of life and with other measures of caregiver health-related quality of life. The PACQLQ functions well as both an evaluative and a discriminative instrument.

Measuring quality of life in children with asthma.

The Paediatric Asthma Quality of Life Questionnaire contains 23 items that children with asthma have identified as troublesome in their daily lives. The aim was to evaluate the measurement properties of the questionnaire. The study design consisted of a 9 week single cohort study with assessments at 1, 5 and 9 weeks. Patients participating in the study were fifty-two children, 7-17 years of age, with a wide range of asthma severity. At each clinic visit, a trained interviewer administered the Paediatric Asthma Quality of Life Questionnaire, the Feeling Thermometer, a clinical asthma control questionnaire and measured spirometry. For 1 week before each clinic visit, patients recorded morning peak flow rates, medication use and symptoms in a diary. The Paediatric Asthma Quality of Life Questionnaire was able to detect quality of life changes in those patients who altered their health status either as a result of treatment or natural fluctuations in their asthma (p < 0.001) and to differentiate these patients from those who remained stable (p < 0.0001). It was reproducible in patients who were stable (ICC = 0.95), which also indicates the instrument's strength to discriminate between subjects of different impairment levels. The questionnaire showed good levels of both longitudinal and cross-sectional correlations with the conventional asthma indices and with general quality of life. The results were consistent across individual domains and different age strata. The Paediatric Asthma Quality of Life Questionnaire has good measurement properties and is valid both as an evaluative and a discriminative instrument. It captures aspects of asthma most important to the patient and adds additional information to conventional clinical outcomes.

Health-related quality of life associated with recombinant human erythropoietin therapy for predialysis chronic renal disease patients.

The investigators evaluated the impact of recombinant human erythropoietin (r-HuEPO) therapy on health-related quality of life (HRQL) in predialysis chronic renal disease patients with anemia. Eighty-three patients were entered into a randomized, parallel-group, open-label clinical trial with follow-up evaluations over 48 weeks. Forty-three patients were assigned to r-HuEPO treatment, and 40 patients were assigned to an untreated control group. Hematocrit levels were measured at baseline and monthly. HRQL was assessed at baseline and at weeks 16, 32, and 48. The HRQL assessment included measures of physical function, energy, role function, health distress, cognitive function, social function, home management, sexual dysfunction, depression, and life satisfaction. Significant improvements in hematocrit levels were observed in the r-HuEPO-treated group (P < 0.0001), and no changes were seen in the untreated group. Correction of anemia (hematocrit > or = 36) occurred in 79% of r-HuEPO-treated patients and 0% of control patients. Significant improvements in assessments of energy (P < 0.05), physical function (P < 0.05), home management (P < 0.05), social activity (P < 0.05), and cognitive function (P < 0.05) were found for the r-HuEPO-treated group. No changes were observed in the control group, except for a decrease in physical function (P < 0.05). Between-group differences favoring the r-HuEPO-treated group were found for energy (P < 0.05) and physical functioning (P < 0.05). In patients receiving r-HuEPO, significant improvements were seen in hemotocrit levels, and these increases resulted in improvements in HRQL.

Evaluation of the Canadian Coordinating Office for Health Technology Assessment.

The Canadian Coordinating Office for Health Technology Assessment (CCOHTA) was recently evaluated. We summarize the evaluation process, report, and 17 recommendations for enhancing CCOHTA's effectiveness. This paper may be useful for evaluators of agencies for technology assessment.

Measuring health-related quality of life.

Clinicians and policymakers are recognizing the importance of measuring health-related quality of life (HRQL) to inform patient management and policy decisions. Self- or interviewer-administered questionnaires can be used to measure cross-sectional differences in quality of life between patients at a point in time (discriminative instruments) or longitudinal changes in HRQL within patients during a period of time (evaluative instruments). Both discriminative and evaluative instruments must be valid (really measuring what they are supposed to measure) and have a high ratio of signal to noise (reliability and responsiveness, respectively). Reliable discriminative instruments are able to reproducibly differentiate between persons. Responsive evaluative measures are able to detect important changes in HRQL during a period of time, even if those changes are small. Health-related quality of life measures should also be interpretable--that is, clinicians and policymakers must be able to identify differences in scores that correspond to trivial, small, moderate, and large differences. Two basic approaches to quality-of-life measurement are available: generic instruments that provide a summary of HRQL; and specific instruments that focus on problems associated with single disease states, patient groups, or areas of function. Generic instruments include health profiles and instruments that generate health utilities. The approaches are not mutually exclusive. Each approach has its strengths and weaknesses and may be suitable for different circumstances. Investigations in HRQL have led to instruments suitable for detecting minimally important effects in clinical trials, for measuring the health of populations, and for providing information for policy decisions.

Evaluation of the burden of illness for pediatric asthmatic patients and their parents.

To examine the quality-of-life burden of asthma in a pediatric population, we systematically surveyed 100 patients with moderate asthma and one parent of each patient to determine the impact of the disease on day-to-day life. We found that perceptions of burden of illness varied by viewpoint. For patients, the symptoms of asthma form the largest component of the burden of the disease; in addition, more than half of the sample listed various emotional function items that were of at least moderate bother to them. Parents cited worry and concern about the disease and the medications used to treat it and their inability to relieve their child's symptoms as the major components of the burden of the disease. We conclude that although pediatric patients with moderate asthma find the respiratory symptoms of the disease troublesome, few children perceive that their asthma poses a major disruption of their lives. For the parents of these patients, strategies could be implemented by clinicians to ease the common worries and concerns surrounding the child's asthma.

Measuring quality of life in clinical trials: a taxonomy and review.

Measurement of quality of life is becoming increasingly relevant to controlled clinical trials. Two basic types of instrument are available: generic instruments, which include health profiles and utility measurements based on the patient's preferences in regard to treatment and outcome; and specific instruments, which focus on problems associated with individual diseases, patient groups or areas of function. The two approaches are not mutually exclusive; each has its strengths and weaknesses and may be suitable under different circumstances. We surveyed 75 randomized trials published in three medical journals in 1986 and categorized them according to the importance of quality of life as a measure of outcome and the extent to which quality of life was actually measured. Although a number of the investigators used quality-of-life instruments in a sophisticated manner, in only 10 of 55 trials in which the measurement had been judged to be crucial or important were instruments with established validity and responsiveness used. We conclude that although accurate measurement of quality of life in randomized trials is now feasible it is still not widely done. Using the framework we have outlined, investigators can choose generic or specific instruments according to the purpose and the focus of their trial.

Incorporating utility-based quality-of-life assessment measures in clinical trials. Two examples.

The utility approach to the measurement of health-related quality of life is discussed and its theoretical foundations and compatibility with economic evaluation are explained. The advantages of the approach include its generalizability, comprehensiveness, ability to integrate mortality and morbidity effects, ability to represent multiple viewpoints, and its incorporation of time and risk preferences in the scores. Disadvantages include interviewer administration, limitations on obtaining scores from all types of subjects, some lack of precision, and attenuated clinical sensibility. Use of the utility approach as an outcome measure in two recent clinical trials is also described. In a trial of an oral gold compound for arthritis, the utility measures were responsive and added information to that from standard clinical and other quality-of-life measures. The utility approach and clinical decision making are being used in an on-going trial of two procedures for prenatal diagnosis in which major potential differences include quality-of-life effects. The comprehensiveness of the utility approach overcomes difficulties in interpreting results from more narrowly focused psychosocial measures of outcome. In sum, the utility model provides a reliable, valid, and responsive approach to measuring quality of life as an outcome in clinical trials.