The Caregiver Activity Survey (CAS): development and validation of a new measure for caregivers of persons with Alzheimer's disease

Background. Most instruments that measure the impairments associated with Alzheimer's disease assess symptom severity. Little attention has been paid to the illness's impact on the time formal and informal caregivers spend caring for Alzheimer's individuals. A tool that measures the time spent caregiving would help to determine the economic impact of the illness. The Caregiver Activity Survey (CAS) was developed to measure the time caregivers spend aiding Alzheimer's patients with their day-to-day activities. Methods. The test–retest reliability of the CAS was assessed during a 3-week study with 42 Alzheimer's patients and their caregivers. The CAS was validated with the Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-Cog), the Mini Mental State Exam (MMSE) and the Physical Self Maintenance Scale (PSMS). Results. The final version of the CAS consists of six items (communicating with the person, using transportation, eating, dressing, looking after one's appearance and supervising the person). The six-item CAS total score has high test–retest reliability, with ICC = 0.88 between weeks 1 and 3. The scale has strong convergent validity with the ADAS-Cog (r = 0.61), MMSE (r = −0.57) and PSMS (r = 0.43). Efforts to include a dimension that reflects caregiver burden were not successful, in part due to the reluctance of caregivers to acknowledge that caregiving is bothersome. Conclusions. The CAS provides a new tool that measures time spent caring for Alzheimer's individuals. The instrument may be used to augment existing clinical assessments that measure the efficacy of potentially therapeutic agents for persons with Alzheimer's disease. © 1997 John Wiley & Sons, Ltd.     

The modified CAMDEX informant interview is a valid and reliable tool for use in the diagnosis of dementia in adults with Down's syndrome

Background Dementia because of Alzheimer's disease (AD) commonly affects older adults with Down's syndrome (DS). Methods are needed, with established concurrent and predictive validity, to facilitate the diagnostic assessment of dementia, when it is complicated by pre‐existing intellectual disabilities (ID). We report on the reliability and validity of a modified version of the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX) informant interview, for use when assessing people with DS suspected as having dementia. Methods As part of a previous epidemiological study of older people with DS, the CAMDEX informant interview was used to determine the prevalence of dementia. The 74 people with DS included at that time (Time 1) had also completed the Cambridge Cognitive Examination (CAMCOG), the neuropsychological assessment from the CAMDEX schedule. Fifty‐six were assessed again 6 years later (Time 2). Based on the CAMDEX informant interview, nine of the 74 at Time 1, and 11 of the 56 at Time 2, were found to meet clinical criteria for AD. Forty‐one scored above floor on the CAMCOG at Time 1 and were included in the analysis of cognitive decline. Concurrent validity was established by comparing diagnosis at Time 2 with independent evidence of objective decline on cognitive tasks since Time 1. Predictive validity was established by examining how accurately diagnosis at Time 1 predicted both cognitive decline and future diagnosis. Inter‐rater reliability was determined by comparing the level of agreement between two raters. Results CAMDEX‐based diagnosis of AD was shown to be consistent with objectively observed cognitive decline (good concurrent validity) and to be a good predictor of future diagnosis. Although numbers are small, some support is also provided for the accuracy with which diagnosis predicts cognitive decline. Inter‐rater reliability was good with Kappa > 0.8 for 91% of items and > 0.6 for all items. Conclusions The use of the modified CAMDEX informant interview enables the structured collection of diagnostic information, so that a valid and a reliable diagnosis of dementia can be made in those with pre‐existing ID, using established diagnostic criteria.     

Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID): development and psychometric properties of a new measure for use with people with mild intellectual disability

Background Self‐rating scales are widely used in general adult practice; however, there is no reliable and valid method for assessing state anxiety in people with intellectual disability (ID). The present study describes the development and psychometric evaluation of a new scale, the Glasgow Anxiety Scale for People with an Intellectual Disability (GAS‐ID). Methods First, an item pool was generated from focus groups, a review of the literature and clinician feedback. Secondly, a draft scale was administered to 19 anxious and 16 non‐anxious people with ID for further validation and appraisal of reliability. Thirdly, the scale was completed by 19 anxious, non‐ID people for cross‐validation with the Beck Anxiety Inventory (BAI). Finally, physiological concomitants were validated by pulse‐oximetry. Results The 27‐item GAS‐ID discriminated anxious from non‐anxious participants, had good test–retest reliability (r = 0.95) and internal consistency (α = 0.96), and was reasonably correlated with the BAI (ρ = 0.75). The correlation between the physiological subscale of the GAS‐ID and changes in pulse rate was moderately significant (ρ = 0.52). Conclusions This preliminary study suggests that the GAS‐ID offers a psychometrically robust and practical (5–10 min) approach to the appraisal of anxiety in this population.     

Reliability and validity of the Chinese version of the Caregiver Reaction Assessment

Aims: The aim of this study was to examine the reliability and validity of the Chinese version of the Caregiver Reaction Assessment, as part of a psychosocial study among family caregivers of cancer patients. Methods: Participants were derived from the Second Affiliated Hospital of China Medical University in Shenyang, China. The research established the internal consistent reliability, test–retest reliability and construct validity. Results: The research comprised 400 family caregivers. The Chinese version of the Caregiver Reaction Assessment showed adequate internal consistency reliability, test–retest reliability and appropriate construct validity. After adjusting items 4, 8, 15 and 18, confirmatory factor analysis confirmed the five new factors of the Chinese version of the Caregiver Reaction Assessment had goodness of fit. Conclusions: These findings suggest that the Chinese version of the Caregiver Reaction Assessment is a reliable and valid instrument for measuring specific aspects of the caregiving experience in the Chinese population.     

Health co-morbidities in ageing persons with Down syndrome and Alzheimer's dementia

Background Consideration of the relationship between physical and mental health co-morbidities in ageing persons with Down syndrome (DS) and Alzheimer's dementia (AD) is of clinical importance both from a care and resource perspective. Aim To investigate and measure health co-morbidities in ageing persons with Down syndrome with and without AD. Methods Recorded physical and mental health needs were ascertained for 124 persons with DS > 35 years through a systematic and detailed search of individual medical and nursing case records. Differences in persons with and without AD were investigated, by stage of dementia and by level of intellectual disability (ID). A summed score for health co-morbidities was created and compared using t-tests. Results Persons with AD had significantly higher co-morbidity scores than persons without AD (t = −8.992, d.f. = 121, P < 0.0001). There was also a significant difference in summed co-morbidity scores for persons at end-stage vs. persons at mid-stage AD (t = −6.429, d.f. = 56, P < 0.0001). No differences were found by level of ID. Conclusions Increasing health co-morbidities in persons with DS and AD have important implications for care and resources. Appropriate environmental supports combined with competent skilled staff are crucial and will have an important impact on the quality of life for this increasingly at risk population.     

Validation of the Subjective and Objective Family Burden Interview (SOFBI/ECFOS) in primary caregivers to adults with intellectual disabilities living in the community

Background There is little information on the psychometric properties of instruments for assessing family care burden in adults with intellectual disabilities (ID). The aim of this study is therefore to analyse the usefulness of the ‘Subjective and Objective Family Burden Interview’ (SOFBI) in the assessment of principal caregivers in Spain. Methods The SOFBI was administered to 166 principal caregivers of adults with ID in a vocational centre. The psychometric analysis included: internal consistency, inter‐rater and test–retest reliability, construct validity, convergent validity with the World Health Organization's Disability Assessment Schedule II, and feasibility. Results The Cronbach's alpha was 0.88 for the overall interview and always above 0.7 in the quantitative subdomains. The Kappa coefficients for test–retest were between 0.5 and 0.8, whereas inter‐rater agreement was nearly perfect. Maximum‐likelihood factor analysis showed four well‐defined factors, which fitted the previously designed domains. Feasibility was also good. Conclusions The SOFBI is a multi‐domain, modular instrument which is feasible, reliable and valid for measuring the burden of family caregivers to adults with ID living in the community.     

Impact of donepezil hydrochloride on the care burden of family caregivers of patients with Alzheimer's disease

Background: To evaluate the impact of donepezil hydrochloride on the care burden on family members of patients with Alzheimer's disease (AD). At present, donepezil is the only drug approved for the treatment of AD in Japan. Although the care burden on primary caregivers of AD patients comprises both physical and psychological burdens and donepezil is recognized to improve cognitive dysfunction and associated symptoms, there are few data on the effects of the drug on the care burden. Methods: Of the uninstitutionalized AD patients who visited a dementia clinic between June 2008 and May 2009 with their primary family caregivers, 416 subjects who satisfied the enrollment criteria were registered for the study. All participants provided informed consent. Assessment included changes in scores on the Japanese version of the Zarit Caregiver Burden Interview (J‐ZBI) and the Mini‐Mental State Examination (MMSE), as well as the presence of behavioral and psychological symptoms of dementia (BPSD). Caregivers answered the questionnaires at baseline and after 12 weeks treatment with donepezil (starting dose 3 mg, p.o., once daily, followed by 5 mg after 1 or 2 weeks). Results: There were significant changes in mean scores on the J‐ZBI (?1.9 ± 9.5; P < 0.01) and MMSE (+0.9 ± 2.9; P < 0.01) from baseline to Week 12, without significant correlation between these two scores. In patients with BPSD, there was a significant decrease in J‐ZBI scores over the 12 weeks (P = 0.013); in contrast, in patients without BPSD, the decrease in the J‐ZBI score did not reach statistical significance (P = 0.418). Conclusions: The results indicate that donepezil improves cognitive function and some of the BPSD. As a possible consequence of improvements in BPSD, donepezil may also reduce caregivers' burden.     

Validity of the Brief Assessment of Impaired Cognition case-finding instrument for identification of dementia subgroups and staging of dementia

Background and purpose

The aims of this study were to examine the psychometric properties of the Brief Assessment of Impaired Cognition (BASIC) case-finding instrument in clinical settings focusing on (i) test–retest reliability, (ii) the discriminative validity of BASIC and its components for identification of Alzheimer disease (AD) dementia and non-AD dementia, and (iii) the association of expert clinical rating of cognitive status with BASIC performance.

Methods

The test–retest reliability analysis was based on a sample of general practice patients (n = 59) retested with a mean interval of 19 days. Discriminative validity analyses and analysis of the association of cognitive status with BASIC performance were based on data from the primary validation study of BASIC in memory clinics.

Results

The test–retest reliability of BASIC was high (r = 0.861). No significant difference in discriminative validity was found for identification of AD dementia (sensitivity = 0.99, specificity = 0.98) and non-AD dementia (sensitivity = 0.90, specificity = 0.98). All components of BASIC contributed to the high discriminative validity of both AD and non-AD dementia. BASIC performance was significantly correlated with expert clinical rating of the cognitive status of patients. A crude staging model for cognitive status using BASIC score intervals had superior classification accuracy (70%) compared to a Mini-Mental State Examination (MMSE) score range-based model (58% accuracy).

Conclusions

BASIC is a reliable and valid case-finding instrument for AD dementia and non-AD dementia in clinical settings. BASIC performance is significantly associated with the degree of cognitive impairment, and BASIC seems to be superior to MMSE for staging of impairment.     

Gender difference and caregivers' burden in early-onset Alzheimer's disease

Background: Caregiver burden is the stress experienced as a result of caregiving. Despite the increasing number of Alzheimer's disease (AD) patients who are cared for at home, little has been published about the caregiver burden pertaining to caregivers of early‐onset AD patients. The objective of this study was to examine the difference between the genders with respect to the careburden of early‐onset AD caregivers. Methods: Twenty‐four patients with early‐onset AD and their caregivers participated in this study. Dementia severity, caregiver's burden, depressive mood and behavioral disturbance were measured and examined. Results: There was no significant difference between female and male caregivers in terms of careburden or depressive mood. However, when correlations were considered, female caregivers showed significant associations between careburden and the patient's age. Associations between the subscales of careburden were also shown for female caregivers. However. there was no significant correlation between the subscales of careburden and dementia severity and the number of behavioral problems for either female or male caregivers. Depression scores showed only correlations with the subscales of careburden for female caregivers. Conclusion: The present study examined the difference between the genders with respect to the care burden experienced by caregivers of early‐onset AD patients. The results reinforce those of previous studies in that female caregivers are more likely to experience careburden than male caregivers. The present study indicates the importance of mental health support for female caregivers.     

Reliability and validity of the Japanese version of the Behavior Problem Inventory-Short Form

BackgroundThe Behavior Problems Inventory-Short Form (BPI-S), which assesses behavior problems in individuals with intellectual disabilities (ID), is a shorter version of the BPI-01. This study investigated the reliability and validity of the BPI-S Japanese version (BPI-S-J) for adolescents/adults with ID and behavior problems.MethodsThe test–retest reliability included participants with ID and behavioral problems who were enrolled in welfare services. For test–retest reliability, 42 caregivers independently responded to the BPI-S-J every two weeks. Inter-rater reliability was independently assessed using the BPI-S-J by two caregivers who were familiar with the 42 participants. The participants of the validity assessment were 227 students from special needs schools or patients with ID admitted to medical institutions. The total frequency total score was compared based on the degree of ID. To examine the criterion-related validity, we analyzed the total frequency score, the total score of the Criteria for Determining Severe Problem Behavior (CDSPB) and the total score of the Aberrant Behavior Checklist-Japanese version (ABC-J).ResultsThe BPI-S-J of test–retest reliability was satisfactory (intra-class correlation; ICC) = 0.954), and the total score significantly (ICC = 0.721) represented good inter-rater reliability. For the validity, the BPI-S-J score of participants who had severe and profound ID was significantly higher than those who had mild and moderate ID. Significant correlations were observed between the BPI-S-J score and CDSPB score (r = 0.499), and the ABC-J score (r = 0.699), indicating adequate criterion-related validity.ConclusionThis study showed the utility of the BPI-S-J to assess behavior problems in the Japanese ID population.     

The association between caregiver burden and caregiver health-related quality of life in Alzheimer disease

The burden experienced by family caregivers of individuals with Alzheimer disease (AD) affects the caregivers' overall health-related quality of life (HRQOL). Assessing the influence on HRQOL is an integral part of determining the efficacy and economic attractiveness of interventions for AD. Generic preference-weighted instruments such as the Health Utilities Index Mark 2 (HUI2) are recommended for measuring HRQOL for cost-effectiveness studies. However, these instruments focus on physical attributes and have not been tested in an AD caregiver population. We administered the HUI2 to a population of 679 caregivers to people with AD at 13 community and institutional sites in the United States. We also administered the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), a caregiver time questionnaire, and a caregiver burden instrument. The mean global HUI2 utility score for caregivers was 0.87 and varied little by the affected person's setting of care and AD stage (range, 0.86-0.89; p > 0.2). The caregiver burden scales all varied by the affected person's setting of care, and some also varied by disease severity. The mental health component summary score of the SF-36 for caregivers varied across both disease stage and setting. Caregiver time increased for caregivers of AD-affected persons with more severe cognitive impairment. Generic preference-weighted instruments may not adequately capture differences in the burden of caregivers of those with AD. The development of condition-specific preference-weighted instruments may provide the means to better estimate HRQOL in AD caregivers.     

Reliability and validity of the Japanese version of the Agitated Behaviour in Dementia Scale in Alzheimer's disease: three dimensions of agitated behaviour in dementia

Background: Agitation in dementia seriously affects not only patients' quality of life (QOL), but also caregivers' QOL. Thus, an appropriate assessment of agitated behaviour in dementia is needed for clinical management. We developed the Japanese version of the Agitated Behaviour in Dementia scale (ABID), examined its reliability and validity, and carried out its factor analysis to elucidate its factor structure. Methods: The Japanese version of the ABID was given caregivers of 149 Japanese patients with Alzheimer's disease (AD). The internal‐consistency, test–retest reliability and concurrent validity of the Japanese version of the ABID were then examined. A factor analysis was used to examine the agitated behavioural dimensions underlying ABID. Results: The Japanese version of the ABID showed an excellent internal reliability for both frequency ratings (Cronbach's α= 0.89) and reaction ratings (Cronbach's α= 0.92), and an excellent test–retest reliability for both frequency ratings and reaction ratings. The total score for the frequency ratings of the ABID was significantly associated with the Cohen‐Mansfield Agitation Inventory (CMAI), and the total score for the reaction ratings of the ABID was significantly associated with the Zarit Burden Interview. The factor analysis showed three subtypes: physically agitated behaviour, verbally agitated behaviour and psychosis symptoms. Conclusions: The Japanese version of the ABID promises to be useful for assessing agitated behaviour in patients with AD. Importantly, understanding these subtypes of agitated behaviour might have implications for individualized treatment plans.     

Validating a Cantonese short version of the Zarit Burden Interview (CZBI-Short) for dementia caregivers

Objectives: The present study aimed to develop and validate a Cantonese short version of the Zarit Burden Interview (CZBI-Short) for Hong Kong Chinese dementia caregivers.

Methods: The 12-item Zarit Burden Interview (ZBI) was translated into spoken Cantonese and back-translated by two bilingual research assistants and face validated by a panel of experts. Five hundred Chinese dementia caregivers showing signs of stress reported their burden using the translated ZBI and rated their depressive symptoms, overall health, and care recipients' physical functioning and behavioral problems. The factor structure of the translated scale was identified using principal component analysis and confirmatory factor analysis; internal consistency and item-total correlations were assessed; and concurrent validity was tested by correlating the ZBI with depressive symptoms, self-rated health, and care recipients' physical functioning and behavioral problems.

Results: The principal component analysis resulted in 11 items loading on a three-factor model comprised role strain, self-criticism, and negative emotion, which accounted for 59% of the variance. The confirmatory factor analysis supported the three-factor model (CZBI-Short) that explained 61% of the total variance. Cronbach's alpha (0.84) and item-total correlations (rho = 0.39–0.71) indicated CZBI-Short had good reliability. CZBI-Short showed correlations with depressive symptoms (r = 0.50), self-rated health (r = ?0.26) and care recipients' physical functioning (r = 0.18–0.26) and disruptive behaviors (r = 0.36).

Conclusions: The 12-item CZBI-Short is a concise, reliable, and valid instrument to assess burden in Chinese dementia caregivers in clinical and social care settings.     

Incidence of dementia in older adults with intellectual disabilities

Dementia may be more common in older adults with intellectual disability (ID) than in the general population. The increased risk for Alzheimer's disease in people with Down syndrome (DS) is well established, but much less is known about dementia in adults with ID who do not have DS. We estimated incidence rates from a longitudinal study of dementia in older adults with ID without DS and compared them to general population rates. 222 participants with ID without DS aged 60 years and older were followed up an average of 2.9 years later to identify those who had declined in functional or cognitive abilities. Those who screened positive had a comprehensive assessment for dementia, diagnosed using ICD 10 and DSM IV criteria. 134 participants who did not have dementia at initial assessment were alive and interviewed at follow up; 21 (15.7%) were diagnosed with dementia. Overall incidence rate for those aged ≥60 was 54.6/1000 person years (95% CI 34.1–82.3). The highest incidence rate (97.8/1000 person years) was in the age group 70–74. Standardised incidence ratio for those aged ≥65 was 4.98 (95% CI 1.62–11.67). Incidence of dementia in older people with intellectual disabilities are up to five times higher than older adults in the general population. Screening may be useful in this population given the high incident rates, particularly as more effective treatments become available. Studies to explore the underlying aetiological factors for dementia associated with intellectual disability could help to identify novel protective and risk factors.     

Is it feasible to assess self-reported quality of life in individuals who are deaf and have intellectual disabilities?

Purpose

There is consensus that Quality of Life (QOL) should be obtained through self-reports from people with intellectual Disability (ID). Thus far, there have been no attempts to collect self-reported QOL from people who are deaf and have ID.

Methods

Based on an established short measure for QOL (EUROHIS-QOL), an adapted easy-to-understand sign language interview was developed and applied in a population (n = 61) with severe-to-profound hearing loss and mild-to-profound ID. Self-reports were conducted at two time points (t₁ and t₂), 6 months apart. The Stark QOL, an established picture-based questionnaire, was also obtained at t₂ and three Proxy ratings of QOL (from caregivers) were conducted for each participant at t₁.

Results

Self-reported QOL was successfully administered at both time points for 44 individuals with mild and moderate ID (IQ reference age between 3.3 and 11.8 years).

The self-reports showed sufficient test–retest reliability and significant correlations with the Stark QOL. As anticipated, self-reported QOL was higher than proxy-reported QOL. Test–retest reliability and internal consistency were good for self-reported QOL.

Conclusion

Reliable and valid self-reports of QOL can be obtained from deaf adults with mild-moderate ID using standard inventories adapted to the linguistic and cognitive level of these individuals.

     

Dementia in Down’s syndrome: an MRI comparison with Alzheimer’s disease in the general population

Background

Down’s syndrome (DS) is the most common genetic cause of intellectual disability. People with DS are at an increased risk of Alzheimer’s disease (AD) compared to the general population. Neuroimaging studies of AD have focused on medial temporal structures; however, to our knowledge, no in vivo case–control study exists comparing the anatomy of dementia in DS to people with AD in the general population. We therefore compared the in vivo brain anatomy of people with DS and dementia (DS+) to those with AD in the general population.

Method

Using MRI in 192 adults, we compared the volume of whole brain matter, lateral ventricles, temporal lobes and hippocampus in DS subjects with and without dementia (DS+, DS-), to each other and to three non-DS groups. These included one group of individuals with AD and two groups of controls (each age-matched for their respective DS and general population AD cohorts).

Results

AD and DS+ subjects showed significant reductions in the volume of the whole brain, hippocampus and temporal lobes and a significant elevation in the volume of the lateral ventricle, compared to their non-demented counterparts. People with DS+ had a smaller reduction in temporal lobe volume compared to individuals with AD.

Conclusions

DS+ and AD subjects have a significant reduction in volume of the same brain regions. We found preliminary evidence that DS individuals may be more sensitive to tissue loss than others and have less ‘cognitive reserve’.     

Burden,perceived health status,and mood among caregivers of Parkinson's disease patients

The objective of this study is to describe the characteristics of the caregivers of patients with Parkinson's disease (PD) and to analyze the association between these characteristics and caregiver burden, perceived health and mood status, and identify their predictors. A multicenter, nationwide, observational, cross‐sectional study that included 289 patient–caregiver pairs was conducted. Caregiver self‐assessments were the Hospital Anxiety and Depression Scale (HADS), EuroQol (EQ), and Zarit Caregiver Burden Inventory (ZCBI). Most caregivers in the study were women aged 60 years or thereabouts. Over two thirds were gainfully employed or housewives, 75% were patients' spouses, and the majority (96.5%) had been permanently taking care of the patient for 6 ± 5.4 years. Less than 5% of patients were in the most advanced stages of disease, and direct costs were 6,350 euros per patient per year. Caregivers had more mood disorders and worse health‐related quality of life (HRQol; EQ‐Tariff) than did the general population. Caregiver HADS and EuroQol scores displayed a weak correlation (r_S = 0.01–0.28) with patient‐related variables (disease duration, HY, SCOPA‐Motor, SCOPA‐AUT, HADS, PPRS, and CISI‐PD) whereas the ZCBI correlated moderately (r_S = 0.27–0.47). Among caregivers, the EQ‐Tariff was significantly lower and the HADS‐Anxiety scores significantly higher for women. ZCBI and HADS‐depression, though not EuroQol and HADS‐anxiety, scores significantly increased with increasing PD severity levels. Caregivers' affective status proved the most important factor influencing their burden and perceived health, whereas patient‐related variables influenced caregiver burden and mood but not health status. In PD, prevalence of affective disorders among patients' caregivers is high and influences both burden and HRQoL. © 2008 Movement Disorder Society     

Magnetic resonance imaging, Down's syndrome and Alzheimer's disease: research and clinical implications

Background The diagnosis of Alzheimer's disease (AD) remains at times difficult to make using available neuropsychological measures. Neuro‐imaging is a relatively new form of detecting the changes associated with dementia. The present study investigated the role of magnetic resonance imaging (MRI) in diagnosing AD in adults with Down's syndrome (DS). Methods Subjects with DS and Alzheimer‐type dementia were matched to non‐demented controls with DS. Magnetic resonance imaging findings (i.e. volumetric and two‐dimensional scans) were compared between the two groups in order to show a relationship between the changes of AD and structural MRI abnormalities. Results Specific structural abnormalities which are seen in non‐intellectually disabled subjects with dementia are also found in individuals with both DS and AD. However, such findings cannot be used to diagnose clinical AD with good accuracy in adults with DS. A number of practical issues of patient compliance and over‐sedation are demonstrated by the findings. Conclusions Magnetic resonance imaging has an important but limited role to play in the management of AD in the population with DS. If intravenous sedation is used, medical support is essential to prevent a serious mishap.     

Zarit Caregiver Burden Interview: Development,reliability and validity of the Chinese version

Aims: To develop a specific scale used in measuring caregiver burden in China, and to evaluate its reliability and validity. Methods: Participants from the First and Second Affiliated Hospital of China Medical University and the Hospital of Tiefa Coal Industry Group completed the Chinese version of the Zarit Caregiver Burden Interview. Results: A total of 523 caregivers were included. The internal consistency of the Zarit Caregiver Burden Interview was high (Cronbach's α 0.875). The item–total correlations were all statistically significant (P < 0.01). Confirmatory factor analysis confirmed the five factors of the Zarit Caregiver Burden Interview in this study, and the goodness‐of‐fit indices reported for this 5‐factor model all fell within the acceptable range. Conclusions: The Chinese version of the Zarit Caregiver Burden Interview is reliable and valid for use. This study has important implications for burden measurement in Chinese caregivers.     

Hippocampal glutamate-glutamine (Glx) in adults with Down syndrome: a preliminary study using in vivo proton magnetic resonance spectroscopy (1H MRS)

Background

Down syndrome (DS), or trisomy 21, is one of the most common autosomal mutations. People with DS have intellectual disability (ID) and are at significantly increased risk of developing Alzheimer’s disease (AD). The biological associates of both ID and AD in DS are poorly understood, but glutamate has been proposed to play a key role. In non-DS populations, glutamate is essential to learning and memory and glutamate-mediated excitotoxicity has been implicated in AD. However, the concentration of hippocampal glutamate in DS individuals with and without dementia has not previously been directly investigated. Proton magnetic resonance spectroscopy (¹H MRS) can be used to measure in vivo the concentrations of glutamate-glutamine (Glx). The objective of the current study was to examine the hippocampal Glx concentration in non-demented DS (DS-) and demented DS (DS+) individuals.

Methods

We examined 46 adults with DS (35 without dementia and 11 with dementia) and 39 healthy controls (HC) using ¹H MRS and measured their hippocampal Glx concentrations.

Results

There was no significant difference in the hippocampal Glx concentration between DS+ and DS-, or between either of the DS groups and the healthy controls. Also, within DS, there was no significant correlation between hippocampal Glx concentration and measures of overall cognitive ability. Last, a sample size calculation based on the effect sizes from this study showed that it would have required 6,257 participants to provide 80% power to detect a significant difference between the groups which would indicate that there is a very low likelihood of a type 2 error accounting for the findings in this study.

Conclusions

Individuals with DS do not have clinically detectable differences in hippocampal Glx concentration. Other pathophysiological processes likely account for ID and AD in people with DS.