Health Status in Patients with Alzheimer’s Disease: An Investigation of Inter-rater Agreement

Measuring the reliability of proxy respondents in behavioural assessments: an open question

BACKGROUND

In behavioural assessment, information can be gathered from internally referenced self-reports or from proxy informants.

AIMS

This study aimed to fine-tune a brief but reliable method for evaluating the proxy accuracy in cases where responses obtained from adult and older adults' patient cannot be considered reliable.

METHODS

We generated a set of items reflecting both overt and covert behaviours related to the basic instrumental activities of daily living. The psychometric properties of the content, factorial, and criterium validity of these items were then checked. The Proxy Reliability Questionnaire-ProRe was created. We tested the frequency of "I don't know" responses as a measure of proxy reliability in a sample of healthy older adults and their proxies, and in a second sample of proxy respondents who answered questions about their parents.

RESULTS

As expected, response precision was lower for items characterizing covert behaviours; items about covert compared to overt behaviours generated more "I don't know" answers. Proxies provided less "I don't know" responses when evaluating the parent, they claimed they knew better. Moreover, we tried to validate our approach using response confidence. Encouragingly, these results also showed differences in the expected direction in confidence between overt and covert behaviours.

CONCLUSIONS

The present study encourages clinicians/researchers to how well the proxy the patient know each other, the tendency of proxies to exhibit, for example, response bias when responding to questions about patients' covert behaviours, and more importantly, the reliability of informants in providing a clinical assessment of neurocognitive diseases associated with aging.

Assessment by proxy of the SF-36 and WHO-DAS 2.0. A systematic review

BACKGROUND AND OBJECTIVE

In some cases, for the evaluation of the health status of patients it is not possible to obtain data directly from the patient. The objective of this study was to determine if the instruments that cannot be applied to the patient can be completed by a proxy.

METHODS

A systematic review of the literature was carried out and 20 studies were included. The instruments reviewed in this synthesis were: Short Form-36 (SF-36), Montreal Cognitive Assessment (MoCA), WHODAS 2.0, Patient Health Questionnaire 9 (PHQ-9), State-Trait Anxiety Inventory (STAI), Disability Rating Scale (DRS).

RESULTS

The levels of agreement between the responses of the patients and the proxies were good, mainly when evaluating HRQoL and functioning with the SF-36 and WHODAS 2.0 instruments, respectively, with a higher level of agreement in the more objective and observable domains such as physical functioning and lower level of agreement in less objective domains, such as emotional or affective status, and self-perception.

CONCLUSION

In patients who cannot complete the different instruments, the use of a proxy can help avoid the omission of responses.

Do we agree or disagree? A systematic review of the application of preference-based instruments in self and proxy reporting of quality of life in older people

PURPOSE

Quality of life is an important person-centred outcome in health and aged care settings. Due to an increasing prevalence of cognitive decline and dementia in ageing populations, a proportion of older people receiving health and aged care services may not be able to reliably assess their own quality of life, highlighting the need for proxy assessment. This systematic review sought to investigate the level of agreement between self and proxy-report of older people's quality of life using established preference-based instruments of quality of life suitable for economic evaluation.

METHODS

A systematic review was conducted following PRISMA guidelines. Eight databases were searched: Web of Science, Scopus, Medline, Econlit, PsychINFO, CINAHL, Ageline and Cochrane Library. Information was extracted on the instruments, population samples (including any cognitive thresholds applied), mean scores, type of proxy, and measures of inter-rater agreement.

RESULTS

A total of 50 studies using eight different preference-based quality of life instruments were identified. Most studies were cross-sectional (72%) with a wide variety of cognitive assessments and thresholds applied to define older participants with cognitive impairment. The most common proxies were family members, mostly spouses. The level of agreement between self and proxy-report was generally poor - irrespective of the instrument applied or type of proxy - with proxy-report generally indicating lower levels of quality of life than self-report. There was some evidence of stronger agreement on more observable quality of life domains e.g., physical health and mobility, relative to less observable domains e.g. emotional well-being. Few studies tracked self and/or proxy-report of quality of life longitudinally.

CONCLUSIONS

More research is needed to develop evidence to inform guidance on self-report versus proxy-report of quality of life for older people receiving health and aged care services. Until then, the collection of both self and proxy reports as complementary measures is indicated.

Proxy reporting of health-related quality of life for people with dementia: a psychometric solution

Background

The growing move towards personalised health and social care systems means that every effort needs to be made to generate patient-reported outcome data. However, the deteriorating nature of dementia can make it difficult for people with dementia to complete self-reported questionnaires and it is often necessary to rely on a family member (proxy) to report on their behalf. There is little evidence to guide how the difference between self- and proxy-reports of health reported quality of life (HRQL) in dementia can be interpreted.

Methods

We recruited people with dementia and their family carers from 78 memory Assessment Services in the UK. We used Rasch measurement methods to investigate whether a HRQL questionnaire known as DEMQOL (self-reported by the person with dementia) and DEMQOL-Proxy (proxy-reported by a family carer) can be placed on the same continuum and whether a revised scoring algorithm, based on this equated model, can be developed that takes account of the relationship between self- and proxy-reports.

Results

In a sample of 1434 patients and 1030 carers, our findings supported equating DEMQOL/DEMQOL-Proxy (overall fit to the model; no mis-fitting items) after addressing specific issues (eight disordered items requiring re-scoring, four pairs locally dependent items, and five items showing DIF). Cross walk tables have been produced.

Conclusions

We have established for the first time that DEMQOL and DEMQOL-Proxy can be placed on the same continuum and that patients and carer proxies are reporting on the same construct when they complete these questionnaires. Where possible both DEMQOL and DEMQOL-Proxy should still be administered together, using the improved scoring algorithm reported here. Where only DEMQOL-Proxy is available, the cross walk tables provide an estimate of DEMQOL for a particular person from their DEMQOL-Proxy score.

A comparison of self and proxy quality of life ratings for people with dementia and their carers: a European prospective cohort study

Objectives: To identify correlates of self-rated and proxy-rated quality of life (QoL) in people with dementia on (i) a dementia-specific and (ii) a capability-wellbeing QoL measure at baseline and 12-month follow-up, and to consider such factors in the context of QoL intervention development.Method: Prospective clinical and demographic data were collected from 451 community-dwelling dyads (mild-moderate dementia) across eight European countries. QoL was measured using the QOL-AD and the ICECAP-O. Multivariate modelling identified correlates of self- and proxy-rated QoL at baseline and at 12-month follow-up.Results: Carer's proxy-ratings of QoL were significantly lower than self-ratings at all time-points for both measures. Proxy-ratings declined over time, but self-ratings remained stable. Baseline predictors of greater self-rated QoL were education, and greater functional ability and relationship quality. Greater proxy-rated QoL was associated with education and greater functional ability, relationship quality, carer social support and carer QoL, lower carer anxiety/depression and less severe neuropsychiatric symptoms in people with dementia. At follow-up, greater self-rated QoL was predicted by greater functional ability, relationship quality, carer social support and having a spousal carer. Greater proxy-rated QoL at follow-up was associated with the same factors as at baseline; however, the dyad living together was an additional predictive factor.Conclusion: Both proxy-ratings and self-ratings of QoL should be interpreted with caution and in the context of each individual caregiving relationship. Different functional, psychosocial, relational and contextual factors influence self- and proxy-ratings, and both sets of factors should be considered in the context of QoL intervention development for the dyad.

Quality of life in dementia: a study on proxy bias

BACKGROUND

Measurement of health-related quality of life (HRQoL) in dementia is difficult. At some point people with dementia become unable to meaningfully assess their own HRQoL. At such a point in time researchers need to rely on other types of information such as observation or assessments from informal caregivers (proxies). However, caregiver assessments may be biased by several mechanisms. The current study explores whether caregivers project part of their own HRQoL in their assessments of patient HRQoL.

METHODS

The participants in the current study were 175 pairs, consisting of community-dwelling persons with dementia and their caregivers. The EQ-5D, the EQ-VAS and the QoL-AD were administered to collect HRQoL measurements from patients and caregivers at baseline, 6 months and 12 months. Two linear mixed models were used to investigate factors that bias proxy ratings, one with the EQ-VAS as dependent variable, and one with the EQ-5D utility as dependent variable. The independent variables were caregiver age, caregiver sex and caregiver QoL-AD items.

RESULTS

The linear mixed model with EQ-VAS as dependent variable indicated that 3 caregiver characteristics, namely caregiver age, money (caregiver's financial situation) and valuation of life as a whole were significant predictors of the patient-by-proxy VAS scores. The linear mixed model with utility value as the dependent variable showed that caregiver age and valuation of the ability to do things for fun were significant predictors of the patient-by-proxy EQ-5D utility values.

CONCLUSIONS

The current study was a first step in identifying factors that bias patient-by-proxy HRQoL assessments. It was discovered that caregivers project part of their own HRQoL onto patients when assessing patient HRQoL. This implies that patient-by-proxy HRQoL values should be interpreted with caution and not be used as a direct substitute for patient self-assessment, even when patients are no longer able meaningfully assess themselves.

Quality of life in dementia: impact of cognition and insight on applicability of the SF-36

OBJECTIVES

Comparability of measures of quality of life in dementia and in other diagnostic groups, such as mild cognitive impairment, normal aging, or other diseases, is highly desirable. However, the impact of cognitive deficits and impaired insight on applicability and validity of generic instruments is sparsely studied.

PARTICIPANTS AND MEASUREMENTS

Sixty patients with dementia [38 women; age: mean (SD) = 78.7 (6.4) years; Mini-Mental State Examination (MMSE): mean (SD) = 20.2 (6.0)] recruited as part of the start-modem study, a multicenter care research study in Germany, completed the generic instrument SF-36 and the specific instrument Quality of Life-Alzheimer's Disease (QOL-AD).

RESULTS

QOL-AD self-rating scores [mean (SD) = 32.8 (5.9)] and SF-36 subscales indicated moderate to good quality of life in the total group. Reliability and validity of five subdomains of the SF-36 were poor in subgroups of patients with impaired insight or with MMSE scores less than 17 (Cronbach's α <0.7, no significant correlation to the QOL-AD). In contrast, for patients with both adequate insight and MMSE score greater than 16 (n = 33; 55%) Cronbach's α of the subdomains of the SF-36 ranged between 0.920 and 0.676. Seven of the eight subdomains correlated significantly with the QOL-AD self-rating and composite score in this group of patients (0.355 ≤ r ≤ 0.709).

CONCLUSIONS

Despite the impact of insight and cognition on self-rated quality of life, we found reliable and valid data for a broad spectrum of patients with dementia. According to the present data, the SF-36 is suitable for dementia patients with both insight into their deficits and an MMSE score greater than 16.

Mapping utility scores from the Barthel index

PURPOSE

It is not always possible to collect utility-based outcome data, like EQ-5D, needed for conducting economic evaluations in populations of older people. Sometimes, information on other non-utility outcome measures may have been collected. This paper examines the possibility of mapping the EQ-5D from a non-utility-based outcome, the Barthel index.

METHODS

Data for 1,189 UK intermediate care patients were used. Ordinary least squares (OLS), censored least absolute deviations (CLAD) estimator and multinomial logistic (ML) models were used. The mean absolute error (MAE) and root-mean-squared error (RMSE) were used to estimate the predictive accuracy of eight regression models. Validation of primary models was carried out on random samples of data collected at admission and discharge.

RESULTS

Models where the EQ-5D was entered as a continuous dependent variable and Barthel dimensions used as explanatory variables performed better. CLAD performed best on MAE and OLS on the RMSE, while the ML performed the worst on both measures. The CLAD predicted EQ-5D scores that matched the observed values more closely than the OLS.

CONCLUSIONS

It is possible to reasonably predict that the EQ-5D from the Barthel using regression methods and the CLAD model (4) is recommended.

Screening for major depressive disorder in adults with glioma using the PHQ-9: a comparison of patient versus proxy reports

When screening for depression in glioma patients, the utility of proxy carer report is unknown. We studied how patients and proxies differed in the frequency, severity and agreement of reported depressive symptoms, the external validity of these reports, and whether patient-proxy agreement was associated with cognitive function. This was a cross-sectional study within a prospective cohort study of depression in glioma. Eligible patients were adults with a new diagnosis of cerebral glioma whose cohabiting partners chose to attend study interviews. Patients completed the Patient Health Questionnaire-9 (PHQ-9, maximum score 27) to screen for major depressive disorder. Proxies independently completed the PHQ-9 'for the patient'. A structured clinical interview for MDD was then given. From 55 couples attending, 41 participated (74 %). Patient-proxy total PHQ-9 score differed by 3 or more points in 26/41 cases (63.4 %). Disagreement within dyads ranged from -7 to +10 points. Proxies observed more individual depressive symptoms than patients reported (mean 2.7 vs 1.8 symptoms respectively, p = 0.013, Wilcoxon Rank Sum Test), and a greater severity of symptom burden (mean PHQ-9 score 8.4 vs 6.8 respectively, p = 0.016, Wilcoxon Rank Sum Test). Proxies were more reliable than patients on objective behavioural symptoms of depression. Dyadic agreement was not associated with severity of patient cognitive impairment. There was frequent disagreement between glioma patients and proxies reports of depressive symptoms. Proxies reported more depressive symptoms than patients, and were more reliable when reporting observable behavioural symptoms. When diagnosing depression in glioma, collateral history should be obtained.

Magnitude and causes of bias among family caregivers rating Alzheimer disease patients

OBJECTIVE

Family caregivers generally underestimate the health and well-being of Alzheimer disease (AD) patients when compared to patients' self-assessments. The goals of this study were to identify caregiver, patient, and contextual factors associated with caregiver rating bias.

METHODS

One hundred five patients with AD, along with their family caregivers, were assessed twice by trained interviewers 1-year apart. In separate interviews, caregivers were asked to rate the quality of life and suffering of their patient relative, and patients provided self-ratings using the same structured instruments. Multivariate cross-sectional and longitudinal analyses were used to identify predictors of caregiver-patient discrepancies.

RESULTS

Caregivers consistently reported significantly higher levels of suffering and lower levels of quality of life than patients. Caregiver psychological well-being and health status accounted for a substantial portion of the difference in caregiver and patient ratings in both cross-sectional and longitudinal analyses. Caregiver depression and burden were consistently positively associated with the magnitude of caregiver-patient discrepancy, and caregiver health status was negatively associated with the size of the discrepancy.

CONCLUSIONS

Caregiver assessments of dementia patients may determine the type and frequency of treatment received by the patient, and caregivers' ability to reliably detect change in patient status can play a critical role in evaluating the efficacy of therapeutic interventions and pharmacologic agents. Clinicians and researchers working with dementia patients who rely on caregiver reports of patient status should be sensitive to the health and well-being of the caregiver and recognize that caregiver assessments may be negatively biased when the caregiver's own well-being is compromised.

Patient and proxy measurement of quality of life among general hospital in-patients with dementia

BACKGROUND

We aimed to investigate quality of life ratings among people with varying severity of dementia and their carers, recruited in general hospital.

METHOD

We recruited 109 people with dementia, and their proxies (carers), from psychiatric referrals of inpatients in two general hospitals in England. From patients, we gathered data on quality of life (QoL-AD and EQ5-D) and depressive symptoms, and from proxies we gathered data on patient quality of life (Proxy QoL-AD and EQ5-D), severity of dementia, activities of daily living, physical illness and depressive symptoms, and on carer stress.

RESULTS

Completion rates for both measures were progressively lower with increasing dementia severity. Patients rated their quality of life more highly than proxies on Qol-AD (patients=32.2, CI=30.7-33.7, proxies=24.7, CI=23.8-26.0, p<0.001) and on EQ5D (patients=0.71, CI=0.64-0.77, proxies=0.30, CI=0.22-0.38, p<0.001). For proxy EQ5D, impaired instrumental ADLs (p=0.003) and more severe dementia (p=0.019) were associated with ratings, while for proxy QoL-AD, only more severe dementia (p=0.039) was associated with ratings. Lower patient EQ-5D scores were independently associated only with carer stress (p=0.01). Lower patient QoL-AD scores were associated with patient depression (p=0.001), impaired activities of daily living (p=0.02) and proxy psychiatric symptoms (p=0.002).

CONCLUSIONS

Among patients with moderate to severe dementia in general hospital, proxy measures of quality of life are the only practical option. Patients and proxies appear to have very different concepts of quality of life in dementia.

Factors associated with caregivers' underestimation of quality of life in patients with Alzheimer's disease

OBJECTIVE

The aim of this study was to identify the factors associated with differences between how Alzheimer's disease (AD) patients and their caregivers rate the patient's health-related quality of life (QoL).

METHODS

Cross-sectional, multicentre study. Patients were 65 years or more, suffering from mild to moderate AD, native French speakers, with a main caregiver. Interrater agreement of the QoL-AD was assessed using the intraclass coefficient. A generalised linear model was used to identify factors related to the difference in health-related QoL scores between patients and their caregivers.

RESULTS

The 122 patients of the study were 82 ± 6 years old and mainly women (69%). Independent factors related to the difference between patients and caregivers were: Mini Mental State Exam score (β = 0.32; 95% CI = 0.05-0.59); instrumental activities of daily living score (β = -0.61; 95% CI = -1.14 to -0.07); total Neuropsychiatric Inventory score (β = 0.10; 95% CI = 0.05-0.59), and Zarit's burden score (β = 0.09; 95% CI = 0.01-0.17).

CONCLUSION

Practitioners must take into account the trend towards underestimation when health-related QoL is rated by caregivers or proxies.

Impact of the life review program on elders with dementia: a preliminary study at a day care center in southern Taiwan

BACKGROUND

: Life review, a type of reminiscence therapy, assists participants to seek personal value in order to enhance social status and maintain a high quality of life (QOL).

PURPOSE

: This study aimed to examine the impact of an adaptive life review program (LRP) on perceived QOL in elders with mild to moderate dementia at a day care center and assess the effect, if any, of different cognitive impairment levels on intervention outcome.

METHODS

: This pre-experimental design used a single group of seven subjects for pretest and posttest and purposive sampling at a 2-week interval. Researchers administered to each subject a 10-day therapeutic recreation program modified from Tabourne's (1991) LRP.

RESULTS

: Posttest results found no statistically significant improvements. However, subjects reported higher mean scores of perceived QOL as measured by the 36-Item Short Form Health Survey. This finding indicated a trend of improving physical and mental health after the intervention. In addition, subjects with moderate cognitive impairment reported a higher improvement in physical health perception than did subjects with mild cognitive impairment.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

: Future research should include a larger sample size and a longer period of intervention and adopt multiple dimensions of QOL measurements to increase research rigor. Suggestions from this study can be used to improve the LRP.

Quality of life in glaucoma and three other chronic diseases: a systematic literature review

Chronic diseases have a long-term negative impact on quality of life (QOL). Decreased QOL is associated with increased financial burden on healthcare systems and society. However, few publications have investigated the impact of glaucoma on patients' QOL in comparison with other chronic diseases observed in patients with similar demographic characteristics. To this end, a systematic literature search to assess QOL in glaucoma and three other chronic diseases (osteoporosis, type 2 diabetes mellitus and dementia) was performed. A total of 146 publications were identified that reported QOL using six commonly used generic QOL instruments: 36-, 12- and 20-item Short-Form Health Surveys (SF-36, -12 and -20), EuroQoL (EQ-5D), Sickness Impact Profile (SIP) and the Health Utilities Index-Mark III (HUI-III). The publication breakdown was as follows: glaucoma (10%), osteoporosis (26%), diabetes (52%) and dementia (12%); one publication assessed QOL in glaucoma, diabetes and dementia. QOL was affected to a similar or slightly lesser degree by glaucoma than by osteoporosis, diabetes or dementia. Among the publications reporting SF-36, -12 and -20 evaluations, physical component scores were generally lower than mental component scores across all diseases. QOL was affected more in patients with glaucoma than in demographically matched non-glaucomatous controls according to SF-20 assessment. EQ-5D and SIP results showed that QOL decreased as the severity of glaucoma increased. Patients with glaucoma had the lowest scores on the SIP instrument, indicating better QOL than patients with osteoporosis or diabetes (no data were available on dementia). The HUI-III instrument identified poorer QOL in patients with dementia than other diseases, probably due to cognitive deficits. However, for some of the instruments, data were scarce, and interpretation of the results should be conservative. Although there are limited published QOL studies in glaucoma, its impact on QOL appears to be broadly similar to that of other serious chronic diseases. Development of a QOL instrument that measures vision-specific and general health aspects would better document the impact of glaucoma on QOL and would facilitate comparisons with other chronic disease states.

Dementia caregiving in spousal relationships: a dyadic perspective

OBJECTIVES

The number of couples facing a dementia diagnosis for one partner of the spousal dyad increases. Spousal caregiving can be a highly stressful experience associated with negative caregiver outcomes such as depression and poorer immune function. However, surprisingly little is known about how the illness and the required care effects patient's well-being and relational changes experienced by afflicted couples. The aim of this study was to provide a literature review on how the dyadic perspective is taken into account and on how dementia effects both parts of the dyad.

METHODS

In order to outline findings about individual and dyadic well-being of affected couples, we conducted a literature search to review the three types of studies. First, studies focusing on one partner's perspective, usually the perspective of the caregiver; second, studies including the caregiver's and partially the care receiver's view; third, studies directly referring to both partners' perspectives.

RESULTS

The majority of studies neglect the individual with dementia by exclusively assessing caregiver variables or only indirectly including patients' characteristics. Very few studies embrace dyadic and relational variables to execute how both partners experience the illness, spousal caregiving, and changes in the relationship. Despite the arguable validity of self reports of individuals with dementia, some studies demonstrated the usefulness of including both partners' perspectives.

DISCUSSION

Results indicate the urgent need of integrating the perspective of the individual with dementia to improve the understanding of the effects of dementia caregiving. Directly assessing the dyadic perspective of affected couples provides essential information for interventions.

Healthcare professionals and managers' participation in developing an intervention: a pre-intervention study in the elderly care context

BACKGROUND

In order to increase the chances of success in new interventions in healthcare, it is generally recommended to tailor the intervention to the target setting and the target professionals. Nonetheless, pre-intervention studies are rarely conducted or are very limited in scope. Moreover, little is known about how to integrate the results of a pre-intervention study into an intervention. As part of a project to develop an intervention aimed at improving care for the elderly in France, a pre-intervention study was conducted to systematically gather data on the current practices, issues, and expectations of healthcare professionals and managers in order to determine the defining features of a successful intervention.

METHODS

A qualitative study was carried out from 2004 to 2006 using a grounded theory approach and involving a purposeful sample of 56 healthcare professionals and managers in Paris, France. Four sources of evidence were used: interviews, focus groups, observation, and documentation.

RESULTS

The stepwise approach comprised three phases, and each provided specific results. In the first step of the pre-intervention study, we gathered data on practices, perceived issues, and expectations of healthcare professionals and managers. The second step involved holding focus groups in order to define the characteristics of a tailor-made intervention. The third step allowed validation of the findings. Using this approach, we were able to design and develop an intervention in elderly care that met the professionals' and managers' expectations.

CONCLUSION

This article reports on an in-depth pre-intervention study that led to the design and development of an intervention in partnership with local healthcare professionals and managers. The stepwise approach represents an innovative strategy for developing tailored interventions, particularly in complex domains such as chronic care. It highlights the usefulness of seeking out the insight of healthcare professionalnd managers and emphasizes the need to intervene at different levels. Further research will be needed in order to develop a more thorough understanding of the impacts of such strategies on the final outcomes of intervention implementations.

A psychometric evaluation of a Swedish version of the Quality of Life in Late-Stage Dementia (QUALID) scale

BACKGROUND

The aim of the present study was to evaluate the validity, reliability and responsiveness of a Swedish translation of the Quality of Life in Late-Stage Dementia (QUALID) Scale.

METHOD

A total of 169 elderly residents at 19 dementia special care units in eight long-term care facilities in the Gothenburg city region participated in the study. Assessments were made by 107 proxy informants.

RESULTS

Results showed satisfactory levels of internal consistency reliability (Cronbach's alpha coefficients 0.74), acceptable inter-rater reliability between informants (0.69), and high test-retest reliability (0.86). As hypothesized, QUALID scores were also associated with those from other quality-of-life (QoL) indices (criterion validity), as well as with use of psychoactive drugs, and with tests of cognitive impairment (clinical validity). The responsiveness of the questionnaire was also acceptable.

CONCLUSIONS

As important clinical decisions may derive from perceived QoL effects, it is vital that the QoL data be reliable, valid and sensitive to change. Our evaluations of the psychometric properties of the Swedish QUALID indicate that it satisfactorily meets the need for an instrument to assess QoL in late-stage dementia in Sweden, in a wide range of settings and applications.