Proxy Ratings Research Articles

Similarity, agreement, and assumed similarity in proxy end-of-life decision making.

Medical decisions near the end of life are often made by proxies who can be inaccurate in their judgments of patient preferences. Given that accuracy in surrogate decision making is an important goal in end-of-life decision making, and in light of that previously seen levels of accuracy reflect substantial disagreement, error, or both, this study examined both relationship and individual factors that potentially affect surrogate accuracy. Specifically, this study examined similarity, agreement, and assumed similarity-a process whereby raters use their own traits and preferences to rate another person-in spousal ratings of end-of-life treatment. This study expands on previous research by examining the potential influence of relationship factors and assumed similarity on end-of-life decision making among a sample of newlyweds. Newly married couples (n = 197) completed self and spouse measures of hypothetical end-of-life preferences and scales assessing marital satisfaction, personality, and attitudes. Results indicate a moderate level of similarity on husband and wife self-rated end-of-life treatment preferences (rs = .18-.29) and a moderate level of agreement between self and proxy ratings (rs = .17-.41). The largest correlations were seen between self ratings and proxy ratings (e.g., husband self ratings and husband proxy ratings of wife preferences, rs = .46-.69), reflecting strong assumed similarity in proxy ratings. For wives, similarity with husbands on a few attitudinal variables (i.e., spirituality, moral strictness, and conservatism) influenced proxy accuracy. Recognizing the potential impact of personal preferences on proxy ratings, as well as the potential influence of relationship factors, may help improve proxy accuracy and end-of-life care for patients and families.

Quality of Life Before Intensive Care Using EQ-5D

To compare patients' retrospectively reported baseline quality of life before intensive care hospitalization with population norms and proxy reports. Prospective cohort study. Thirteen ICUs at four teaching hospitals in Baltimore, MD. One hundred forty acute lung injury survivors and their designated proxies. Around the time of hospital discharge, both patients and proxies were asked to retrospectively estimate patients' baseline quality of life before hospital admission using the EQ-5D quality-of-life instrument. Mean patient-rated EQ-5D visual analog scale scores and utility scores were significantly lower than population norms but were significantly higher than proxy ratings. However, the magnitude of difference in average utility scores between patients and either population norms or proxies was not clinically important. For the five individual EQ-5D domains, κ statistics revealed slight to fair agreement between patients and proxies. Bland-Altman plots demonstrated that for both the visual analog scale and utility scores, proxies underestimated scores when patients reported high ratings and overestimated scores for low patient ratings. Patients retrospectively reported worse baseline health status before acute lung injury than population norms and better status than proxy reports; however, the magnitude of these differences in health status may not be clinically important. Proxies had only slight to fair agreement with patients in all five EQ-5D domains, attenuating patients' more extreme ratings toward moderate scores. Caution is required when interpreting proxy retrospective reports of baseline health status for survivors of acute lung injury.

Quality of life and BMI changes in youth participating in an integrated pediatric obesity treatment program

BackgroundChanges in Quality of Life (QOL) measures over time with treatment of obesity have not previously been described for youth. We describe the changes from baseline through two follow up visits in youth QOL (assessed by the Pediatric Quality Life Inventory, PedsQL4.0), teen depression (assessed by the Patient Health Questionnaire, PHQ9A), Body Mass Index (BMI) and BMI z-score. We also report caregiver proxy ratings of youth QOL.MethodsA sample of 267 pairs of youth and caregiver participants were recruited at their first visit to an outpatient weight-treatment clinic that provides care integrated between a physician, dietician, and mental health provider; of the 267, 113 attended a visit two (V2) follow-up appointment, and 48 attended visit three (V3). We investigated multiple factors longitudinally experienced by youth who are overweight and their caregivers across up to three different integrated care visits. We determined relationships at baseline in QOL, PHQ9A, and BMI z-score, as well as changes in variables over time using linear mixed models with time as a covariate.ResultsOverall across three visits the results indicate that youth had slight declines in relative BMI, significant increases in their QOL and improvements in depression.ConclusionsWe encourage clinicians and researchers to track youth longitudinally throughout treatment to investigate not only youth’s BMI changes, but also psychosocial changes including QOL.

Self‐rated and parent‐rated quality of life (QoL) for community‐based obese and overweight children

To determine the effects of being obese or overweight on quality of life (QoL) of children from a community-based sample and to compare their self-ratings of QoL with their parents' ratings for their children's QoL. Dyads of 8- to 12-year-old children [60 obese, 34 overweight and 127 normal weight (N=221)] and their parents or caregivers were recruited from southern Taiwan. QoL was assessed by both parent proxy ratings and child self-ratings using the Pediatric Quality of Life Inventory (PedsQL) questionnaire. Obese children reported significantly lower QoL than did their normal-weight counterparts (83±15 vs. 88±10; p=0.04). Obese children rated their QoL lower than did their parents in all (Cohen's d=-0.38 to -0.22) but the school domain. Overweight children's and normal-weight children's self-reported QoL was not significantly different, nor were they different from parent-reported QoL. Community-based obese children reported a lower QoL than did normal-weight children; however, their parents seemed unaware of their children's decreased QoL. Caution is required when using only parent proxy reports to assess the QoL of obese children. More effort is needed in Taiwan to improve parents' understanding of their obese children's QoL.

Expert Versus Proxy Rating of Verbal Communicative Ability of People with Aphasia after Stroke

In randomized clinical trials of aphasia treatment, a functional outcome measure like the Amsterdam-Nijmegen Everyday Language Test (ANELT), administered by speech-language therapists, is often used. However, the agreement between this expert rating and the judgment of the proxy about the quality of the daily life communication of the person with aphasia is largely unknown. We examined the association between ANELT scores by speech-language therapists and proxy judgments on the Partner Communication Questionnaire both at 3 and 6 months in 39 people with aphasia after stroke. We also determined which factors affected the level of agreement between expert and proxy judgment of the communicative ability at 6 months in 53 people with aphasia. We found moderate agreement (at 3 months r = .662; p = < .0001 and at 6 months r = .565; p = .0001), with proxies rating slightly higher than experts. Less severe aphasia, measured with the Aphasia Severity Rating Scale, was associated with better agreement. In conclusion, although proxies were slightly more positive than experts, we found moderate agreement between expert and proxy rating of verbal communicative ability of people with aphasia after stroke, especially in milder cases.

Challenge of assessing symptoms in seriously ill intensive care unit patients

Determine levels of agreement among intensive care unit patients and their family members, nurses, and physicians (proxies) regarding patients' symptoms and compare levels of mean intensity (i.e., the magnitude of a symptom sensation) and distress (i.e., the degree of emotionality that a symptom engenders) of symptoms among patients and proxy reporters. Prospective study of proxy reporters of symptoms in seriously ill patients. Two intensive care units in a tertiary medical center in the Western United States. Two hundred and forty-five intensive care unit patients, 243 family members, 103 nurses, and 92 physicians. None. On the basis of the magnitude of intraclass correlation coefficients, where coefficients from .35 to .78 are considered to be appropriately robust, correlation coefficients between patients' and family members' ratings met this criterion (≥.35) for intensity in six of ten symptoms. No intensity ratings between patients and nurses had intraclass correlation coefficients >.32. Three symptoms had intensity correlation coefficients of ≥.36 between patients' and physicians' ratings. Correlation coefficients between patients and family members were >.40 for five symptom-distress ratings. No symptoms had distress correlation coefficients of ≥.28 between patients' and nurses' ratings. Two symptoms had symptom-distress correlation coefficients between patients' and physicians' ratings at >.39. Family members, nurses, and physicians reported higher symptom-intensity scores than patients did for 80%, 60%, and 60% of the symptoms, respectively. Family members, nurses, and physicians reported higher symptom-distress scores than patients did for 90%, 70%, and 80% of the symptoms, respectively. Patient-family intraclass correlation coefficients were sufficiently close for us to consider using family members to help assess intensive care unit patients' symptoms. Relatively low intraclass correlation coefficients between intensive care unit clinicians' and patients' symptom ratings indicate that some proxy raters overestimate whereas others underestimate patients' symptoms. Proxy overestimation of patients' symptom scores warrants further study because this may influence decisions about treating patients' symptoms.

Health-related quality of life functioning over a 2-year period in children with end-stage renal disease

Optimal care of the pediatric chronic kidney disease/end stage renal disease (CKD/ESRD) patient must now incorporate health-related quality of life (HRQOL) assessment and management. This study reports the first data on longitudinal change in global (PedsQL(TM)4.0) and disease-specific (PedsQL(TM)3.0 ESRD Module) HRQOL pediatric ESRD patient and proxy ratings over four assessment periods spanning approximately a 2-year period. General linear mixed modeling was used to analyze associations between patient demographics, medical variables, and patient and proxy HRQOL scores. Self-reported and/or proxy data were available for at least two time-points for 53 patients (age 2-18years; 60 % male), of whom 27 were receiving in-center hemodialysis. Patient ratings on global health and physical activity, emotional, and social and disease-specific worry and communication domains were higher (i.e., better) than parent-proxy ratings, confirming the importance of obtaining both sources of information. Patients on dialysis longer, particularly females, reported worse emotional functioning; females also reported more physical appearance concerns. Parents rated older children and those on dialysis longer as functioning worse on multiple global and disease-specific (e.g., fatigue, relationship) domains. Parents also rated children as functioning increasingly worse in school over time. Further, patient ESRD history (acute onset vs. medically managed) impacted how parents viewed the burden of ESRD on their child over time.

Relationship between Self‐Report and Proxy Ratings on Assessed Personal Quality of Life‐Related Outcomes

AbstractQuality of life scores obtained from self‐reports might not be the same as those obtained from a family member or direct support staff. The purpose of the two studies reported in this article was to evaluate further the impact on quality of life scores of self‐report vs. proxy ratings. The Personal Outcomes Scale was administered to persons with an intellectual disability. The self‐report version, as well as the direct observation version, was administered. In the use of the direct observation form, direct support staff and family members acted as respondents. Study 1, which evaluated the consistency between self‐report and direct observation data using support staff as proxy respondents, found significant mean differences between the two respondent groups in three quality of life domains and an acceptable level of internal consistency for both self‐report and direct observation strategies. Study 2, which evaluated the difference between self‐report (by the client) and proxy ratings (of the same individual) using direct observation interviews with family and support staff as respondents, found some differences between client and staff ratings but no significant differences between client and family ratings. Correlations between respondent group scores fell within the “good category.” The authors noted the need for methodological pluralism in quality of life assessment, the importance of self‐report by persons with intellectual disability, and the need to develop better and more reliably user‐friendly strategies to evaluate quality of life outcomes for those individuals who either do not or cannot respond for themselves.

Prevalence of Cognitive Impairment in Older Adults with Heart Failure

To determine the prevalence of cognitive impairment in older adults with heart failure (HF). Cross-sectional analysis of the 2004 wave of the nationally representative Health and Retirement Study linked to 2002 to 2004 Medicare administrative claims. United States, community. Six thousand one hundred eighty-nine individuals aged 67 and older. An algorithm was developed using a combination of self- and proxy report of a heart problem and the presence of one or more Medicare claims in administrative files using standard HF diagnostic codes. On the basis of the algorithm, three categories were created to characterize the likelihood of a HF diagnosis: high or moderate probability of HF, low probability of HF, and no HF. Cognitive function was assessed using a screening measure of cognitive function or according to proxy rating. Age-adjusted prevalence estimates of cognitive impairment were calculated for the three groups. The prevalence of cognitive impairment consistent with dementia in older adults with HF was 15%, and the prevalence of mild cognitive impairment was 24%. The odds of dementia in those with HF were significantly higher, even after adjustment for age, education level, net worth, and prior stroke (odds ratio = 1.52, 95% confidence interval = 1.14-2.02). Cognitive impairment is common in older adults with HF and is independently associated with risk of dementia. A cognitive assessment should be routinely incorporated into HF-focused models of care.

Assessing parent–child agreement in health-related quality of life among three health status groups

To examine parent-child agreement regarding a child's health-related quality of life (HRQOL) among three health status groups. Parent-child agreement was evaluated for three health status groups of a population-based sample: (1) children with mental health problems (N=461), (2) children with physical health problems (N=281), and (3) healthy controls (N=699). The KIDSCREEN-27 was used to assess HRQOL. The children were 9-14years of age. Intraclass correlation coefficients were mostly good across all HRQOL scores and health status groups. This relatively high level of agreement was also reflected by the following findings: first, the AGREE group was the largest in three out of five HRQOL subscales in all health status groups; second, when disagreement occurred, it was often minor in magnitude. Despite this relatively high level of agreement, the means of self-ratings were significantly higher for all HRQOL scores and health status groups than the means of proxy ratings. These higher self-ratings were especially pronounced among children with mental health problems in certain HRQOL domains. Even though the level of parent-child agreement regarding a child's HRQOL is relatively high, it should be considered that children (especially those with mental health problems) often report better HRQOL than their parents. It is, therefore, highly recommended that both proxy- and self-ratings are used to evaluate a child's HRQOL comprehensively.

Self‐concept in early stage dementia: profile, course, correlates, predictors and implications for quality of life

Although it is increasingly accepted that people with dementia retain a sense of self, there is a need for empirical evidence regarding the nature of the self-concept in early stage dementia, how this changes over time and how it relates to quality of life. Self-concept was assessed using the short form of the Tennessee Self-concept Scale in 95 individuals with early stage dementia; 63 were reassessed after 12 months, and 45 were seen again at 20 months. Participants also completed measures of mood, cognitive functioning and quality of life. Caregivers provided proxy ratings of self-concept, completed measures of symptoms and distress at symptoms and rated their own levels of stress and well-being. Self-ratings of self-concept were close to the average range for the standardization sample, and the distribution did not differ significantly from expected values. Although caregiver ratings were slightly lower, discrepancies were small. There were no significant changes over time in self-ratings or informant ratings or discrepancies. At Time 1, self-ratings were predicted by anxiety, depression and memory, caregiver ratings were predicted by caregiver distress and by depression in the person with dementia and discrepancies were predicted by caregiver distress. These models remained predictive at later time points. Self-rated self-concept predicted quality of life, with the relationship only partially mediated by depression and anxiety. Self-concept appears largely intact in early stage dementia, but in view of the association between self-concept and quality of life, a preventive approach focused on supporting self-concept may offer benefits as dementia progresses.

Discrepancy Between Self‐ and Proxy‐Rated Pain in Alzheimer's Disease: Results from the Danish Alzheimer Intervention Study

To investigate the prevalence of self- and proxy-reported pain in a cohort with Alzheimer's disease (AD) and to identify characteristics of individuals with AD reporting pain. Data were collected at the baseline visit of the Danish Alzheimer Intervention Study. Community. Three hundred twenty-one community-living individuals with AD (MMSE ≥ 20) and their primary caregivers. Pain was assessed as part of the EuroQol EQ-5D (caregiver- and self-rated). The Cornell Scale for Depression in Dementia, Quality of Life in Alzheimer's Disease Scale, EQ-5D visual analog scale, Mini-Mental State Examination, and Neuropsychiatric Inventory Questionnaire were also used. Fair agreement was found between self- and proxy ratings on pain (kappa = 0.34). Thirty-three percent of individuals with AD reported pain, whereas caregivers reported that 52% had pain ( P < .001). Individuals who had self- or proxy-rated pain were significantly more likely to be female, had more depressive and other neuropsychiatric symptoms, and rated their quality of life lower. Self- and proxy-reported pain differ in individuals with mild AD, with proxies rating more pain than the individuals with AD. Self- and proxy-rated pain was significantly associated with more neuropsychiatric and depressive symptoms and lower quality of life. In general, this study indicates that pain occurs frequently even in individuals with mild AD and that pain assessment may require self- and proxy report to identify individuals with need for possible treatment.

Could the choice of patient versus proxy ratings for assessing quality of life in dementia affect resource allocation in health care?

OBJECTIVE: The aim of this paper is to demonstrate how the choice of patient versus proxy ratings of patient health-related quality of life (HRQoL) in dementia, for use in cost-effectiveness analyses (CEAs), could potentially affect resource allocation in health care.METHODS:A model of Alzheimer’s disease (AD) based on cognitive ability was used to assess the consequences of using HRQoL ratings from either patients themselves or proxies if a new treatment was to be introduced. The model was based on previously published data on costs related to AD stages as well as HRQoL ratings from AD patients and from their caregivers as proxy raters.RESULTS:The results show that there can be large differences in the results of the CEAs depending on whether the ratings of patients’ HRQoL were made by the patients themselves or by the proxy. When patient self-ratings of HRQoL were used, the cost/quality-adjusted life year (QALY) gained was much higher as compared to the scenario when proxy ratings were used for the same analysis.CONCLUSIONS: The choice of patient self-ratings compared to proxy ratings of patients’ HRQoL can have a substantial effect on the results of CEAs. These differences in results may have an important impact on decision making and, ultimately, on resource allocation. In order to critically appraise the results of CEA studies in dementia we advise that both patient and proxy ratings are used in the CEA. To decide on methodology it is of great importance that focus is directed towards determining the most valid way to measure HRQoL in AD.

Health-related quality of life: cross-informant agreement of father, mother, and self-report for children and adolescents in outpatient psychotherapy treatment.

To study the cross-informant agreement between father, mother harm avoidance and child rating of health-related quality of life (HRQoL) in a psychiatric sample. Data were obtained from 127 children and adolescents (aged 6-18) commencing outpatient psychotherapy treatment, mainly for anxiety, depressive, and externalising disorders. A total of 100 mothers, 69 fathers harm avoidance and 76 children (aged 11years and older) filled out questionnaires. HRQoL was measured with the KIDSCREEN-27. Cross-informant agreement was moderate to high between parents and moderate to low between father-child and mother-child pairs. Both parents reported lower HRQoL than the children themselves. Standardised discrepancies correlated with gender, overall and internalising pathology, as well as harm avoidance to a small degree. Although there was moderate-to-high correspondence, mother and father reports were not interchangeable. When collecting a single-parent proxy rating on the child's HRQoL, researchers should be aware of the additional potential source of variance due to differing concordance of father and mother with the child's self-report especially for peer relations.

Health-related quality of life in Huntington’s disease patients: a comparison of proxy assessment and patient self-rating using the disease-specific Huntington’s disease health-related quality of life questionnaire (HDQoL)

Huntington’s disease (HD) is a fatal, neurodegenerative disease for which there is no known cure. Proxy evaluation is relevant for HD as its manifestation might limit the ability of persons to report their health-related quality of life (HrQoL). This study explored patient–proxy ratings of HrQoL of persons at different stages of HD, and examined factors that may affect proxy ratings. A total of 105 patient–proxy pairs completed the Huntington’s disease health-related quality of life questionnaire (HDQoL) and other established HrQoL measures (EQ-5D and SF-12v2). Proxy–patient agreement was assessed in terms of absolute level (mean ratings) and intraclass correlation. Proxies’ ratings were at a similar level to patients’ self-ratings on an overall Summary Score and on most of the six Specific Scales of the HDQoL. On the Specific Hopes and Worries Scale, proxies on average rated HrQoL as better than patients’ self-ratings, while on both the Specific Cognitive Scale and Specific Physical and Functional Scale proxies tended to rate HrQoL more poorly than patients themselves. The patient’s disease stage and mental wellbeing (SF-12 Mental Component scale) were the two factors that primarily affected proxy assessment. Proxy scores were strongly correlated with patients’ self-ratings of HrQoL, on the Summary Scale and all Specific Scales. The patient–proxy correlation was lower for patients at moderate stages of HD compared to patients at early and advanced stages. The proxy report version of the HDQoL is a useful complementary tool to self-assessment, and a promising alternative when individual patients with advanced HD are unable to self-report.

Self-reported quality of life ratings of people with dementia: the role of attitudes to aging

Attitudes to aging have not previously been assessed in people with dementia. The possession of positive life attitudes into older age has the potential to induce resilience to health changes and may explain the discrepancy between self-reported and proxy ratings of quality of life (QoL). The aim of this study was to explore the attitudes of people with dementia to determine the main factors that predict these attitudes and any relationship that exists with self-reported QoL. Fifty-six participants with dementia were recruited from a memory clinic setting. The Bath Assessment of Subjective Quality of Life in Dementia, Attitudes to Aging Questionnaire (AAQ), Memory Functioning Scale, Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory, and Mini-Mental State Examination were administered. The AAQ was also completed by 86 community-dwelling older adults without dementia. Participants with dementia displayed a significantly stronger endorsement of the negative attitude that aging is a time of psychosocial loss than those without dementia. Regression analyses suggest this negative attitude acts as a partial mediator in the relationship between the person's level of insight and self-reported QoL. Negative attitudes to aging had a direct impact on the self-reported QoL ratings of people with dementia. The view of aging as a time of psychosocial loss was most significant for people with dementia and suggests that negative stereotypes of dementia need to be challenged. In order to promote QoL, care should focus on abilities that the person retains rather than what has been lost.

Evaluation of Patient and Proxy Responses on the Activity Measure for Postacute Care

Our objective was to examine the agreement between adult patients with stroke and family member or clinician proxies in activity measure for postacute care (AM-PAC) summary scores for daily activity, basic mobility, and applied cognitive function. This study involved 67 patients with stroke admitted to a hospital within the Kaiser Permanente of Northern California system and were participants in a parent study on stroke outcomes. Each participant and proxy respondent completed the AM-PAC by personal or telephone interview at the point of hospital discharge or during ≥1 transitions to different postacute care settings. The results suggest that for patients with a stroke proxy, AM-PAC data are robust for family or clinician proxy assessment of basic mobility function and clinician proxy assessment of daily activity function, but less robust for family proxy assessment of daily activity function and for all proxy groups' assessments of applied cognitive function. The pattern of disagreement between patient and proxy was, on average, relatively small and random. There was little evidence of systematic bias between proxy and patient reports of their functional status. The degree of concordance between patient and proxy was similar for those with moderate to severe strokes compared with mild strokes. Patient and proxy ratings on the AM-PAC achieved adequate agreement for use in stroke research when using proxy respondents could reduce sample selection bias. The AM-PAC data can be implemented across institutional as well as community care settings while achieving precision and reducing respondent burden.

Canadian Occupational Performance Measure: Impact of Blinded Parent-Proxy Ratings on Outcome

There is potential for unintended effects on intervention outcome when using the Canadian Occupational Performance Measure (COPM) in intervention studies. To determine the effect of blinded parent-proxy ratings of the COPM on outcomes at later endpoints. Data were drawn from a randomized trial of 50 children with hemiplegic cerebral palsy aged 19 months to seven years. Outcomes were measured at baseline, post-intervention, and six months. Parents of 36 children were randomly allocated to complete six-month COPM proxy ratings blinded or unblinded to previous ratings. A group of 32 parents rated the six-month COPM blinded and then re-rated it after access to previous ratings. There was no statistically significant difference in ratings between those completing the COPM blinded compared to unblinded. The COPM should continue to be rated blinded at post-intervention endpoints in the absence of further research to the contrary.

Relationship of Sleep Quality and Health-Related Quality of Life in Adolescents According to Self- and Proxy Ratings: A Questionnaire Survey

Introduction: Sleep disturbances are common in adolescents and adversely affect performance, social contact, and susceptibility to stress. We investigated the hypothesis of a relationship between sleep and health-related quality of life (HRQoL), and applied self- and proxy ratings. Materials and Methods: The sample comprised 92 adolescents aged 11–17 years. All participants and their parents completed a HRQoL measure and the Sleep Disturbance Scale for Children (SDSC). Children with SDSC T-scores above the normal range (above 60) were classified as poor sleepers. Results: According to self- and proxy ratings, good sleepers reported significantly higher HRQoL than poor sleepers. Sleep disturbances were significantly higher and HRQoL significantly lower in self- as compared to parental ratings. Parent-child agreement was higher for subscales measuring observable aspects. Girls experienced significantly stronger sleep disturbances and lower self-rated HRQoL than boys. Discussion: Our findings support the positive relationship of sleep and HRQoL. Furthermore, parents significantly underestimate sleep disturbances and overestimate HRQoL in their children.

Health State Values for Use in the Economic Evaluation of Treatments for Alzheimerʼs Disease

Alzheimer's disease (AD) is a chronic, progressive, neurodegenerative disease that places a heavy burden on people with the condition, their families and carers, health care systems and society in general. Health-related quality of life (HR-QOL) in patients deteriorates as the cognitive, behavioural and functional symptoms of AD develop. The human and financial cost of AD is forecast to grow rapidly as populations age, and those responsible for planning and financing health care face the challenge of allocating increasingly scarce resources against current and future interventions targeted towards AD. These include calls for early detection and diagnosis, preventative strategies, new medications, residential care, supportive care, and meeting the needs of carers as well as patients. Health care funders in many health systems now require a demonstration of the value of new interventions through a comparison of benefits in terms of improvements in HR-QOL and costs relative to those of competing or existing practices. Changes in HR-QOL provide the basis for the calculation of the quality-adjusted life-year (QALY), a key outcome used in economic evaluations to compare treatments within and between different disease conditions. The objective of this systematic review was to provide a summary of the published health state values (utilities) for AD patients and their carers that are currently available to estimate QALYs for use in health economic evaluations of interventions in AD. The health care literature was searched for articles published in English between 2000 and 2011, using keywords and variants including 'quality-adjusted life years', 'health state indicators', 'health utilities' and the specific names of generic measures of HR-QOL and health state valuation techniques. Databases searched included MEDLINE, EMBASE, NHS EED, PsycINFO and ISI Web of Science. This review identified 12 studies that reported utility values associated with health states in AD. Values for AD health states categorized according to cognitive impairment (where 1 = perfect health and 0 = dead) ranged from mild AD (0.52-0.73) to moderate AD (0.30-0.53) to severe AD (0.12-0.49). Utility values were almost all based on two generic measures of HR-QOL: the EQ-5D and Health Utility Index mark 2/3 (HUI2/3). There were no health state values estimated from condition- or disease-specific measures of HR-QOL. The review also identified 18 published cost-utility analyses (CUAs) of treatments for AD. The CUAs incorporated results from only three of the identified health state valuation studies. Twelve CUAs relied on the same study for health state values. We conclude that the literature on health state values in AD is limited and overly reliant on a single symptom (cognition) to describe disease progression. Other approaches to characterizing disease progression in AD based on multiple outcomes or dependency may be better predictors of costs and utilities in economic evaluations. Patient and proxy ratings were poorly correlated, particularly in patients with more advanced AD. However, proxy ratings displayed the validity and reliability across the entire range of AD severity needed to detect long-term changes relevant to economic evaluation. Further longitudinal research of patient and carer HR-QOL based on multidimensional measures of outcome and utilities is needed.