Validation of a German version of the dementia screening questionnaire for individuals with intellectual disabilities (DSQIID-G) in Down's syndrome.

BACKGROUND: People with Down's syndrome (DS) are at high risk of developing Alzheimer dementia (DS-AD) due to a triplication of the amyloid precursor protein gene. While several tools to diagnose and screen for DS-AD, such as the dementia screening questionnaire for individuals with intellectual disabilities (DSQIID), are available in English, validated German versions of such instruments are scarce. METHODS: A German version of the DSQIID questionnaire (DSQIID-G) was completed by caregivers before attending our specialist outpatient department for DS-AD. All participants were assessed blind to DSQIID-G scoring using clinical and neuropsychological examinations, including the Cambridge Examination for Mental Disorders of Older People with Down's Syndrome and Others with Intellectual Disabilities (CAMDEX-DS). ICD-10 and amyloid/tau/neurodegeneration (A/T/N) criteria were applied to detect and categorise cognitive decline. RESULTS: Of 86 participants, 43 (50%) showed evidence of cognitive decline. A definite diagnosis of DS-AD was reached in 17 (19.8%) and mild cognitive impairment in seven (8.3%) participants. Secondary causes of cognitive decline were determined among 13 (15.1%) participants, and in six (7%) cases, the diagnosis remained unclassifiable due to co-morbidities. Compared with cognitively stable individuals, participants with cognitive decline (n = 43) displayed higher DSQIID-G total scores [median (range): 3 (0-21) vs. 19 (0-48), P < 0.001]. A total score of >7 provided a sensitivity of 0.94 against a specificity of 0.76, to discriminate DS-AD and participants without cognitive decline according to ROC analysis. The convergent validity against the CAMDEX-DS interview score was good (r = 0.74), and split-half reliability (r = 0.96), internal consistency (Cronbach's α r = 0.96), test-retest reliability (r = 0.88) (n = 25) and interrater reliability (r = 0.81) (n = 31) were excellent. CONCLUSIONS: The DSQIID-G showed excellent psychometric properties, including concurrent and internal validity and reliability. The cut-off value for screening was lower than in the original English validation study. For a screening instrument like DSQIID-G, a lower cut-off is preferable to increase case detection.

Validation of the German version of the DSQIID in adults with intellectual disabilities.

BACKGROUND: An observer-rated screening questionnaire for dementia for people with intellectual disabilities (ID), DSQIID, was developed in the UK. So far, the German version has not yet been validated in adults with ID. AIMS/METHODS: We validated a German version of DSQIID (DSQIID-G) among adults with ID attending a German clinic. PROCEDURES/OUTCOMES: DSQIID-G was completed by the caregivers of 104 adults with ID at baseline (T1), 94 at six months (T2) and 83 at 12 months (T3). A Receiver Operating Curve (ROC) was used to determine the total DSQIID-G cutoff score for the best fit between sensitivity and specificity. RESULTS: Sixteen of the 104 participants at T1 (15%) received a diagnosis of dementia. At T1, the scores among the non-dementia group ranged from 0 to 33 (mean: 6.7; SD: 7.65), and the dementia group ranged from 3 to 43 (mean: 22.12; SD: 11.6). The intergroup difference was statistically significant (W: 158; p < .001) (AUC:.89). A total score of 9 provided the best fit between sensitivity (.94) and specificity (.72). CONCLUSIONS AND IMPLICATIONS: DSQIID-G total score can discriminate between dementia and non-dementia cases in adults with ID. A lower cutoff score with a higher sensitivity is desirable for a screening instrument.

Validation of the Japanese version of the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities.

BACKGROUND: Dementia in people with intellectual disabilities (IDs) is difficult to detect because of preexisting cognitive deficits. An effective screening method is required. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was developed as an observer rating tool to screen dementia in people with ID. The aim of this study was to verify the screening accuracy of the DSQIID for Japanese people with ID. METHODS: Four-hundred ninety-three subjects with ID participated in this study. Caregivers who had observed the participants for more than 2 years scored the Japanese version of the DSQIID (DSQIID-J) of the participants. Three doctors examined participants directly and diagnosed dementia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria. To identify the key screening items that predict dementia, the specificities of a single and pairs of items with 100% sensitivity were evaluated relative to the dementia diagnosis. RESULTS: Of 493 participants, 34 were people with Down syndrome (DS), and 459 were people without DS. Seventeen participants were diagnosed with dementia. The suitable cut-off score of the DSQIID-J was 10/11 (sensitivity 100% and specificity 96.8%) for screening dementia. The inter-rater reliability, test-retest reliability and internal consistency of the DSQIID-J were excellent. Regarding key items, there was no single item with 100% sensitivity, and the best two-item combination was the pair of 'Cannot dress without help' and 'Walks slower' (sensitivity 100% and specificity 93.5%). CONCLUSIONS: We identified several important question items of the DSQIID-J related to the diagnosis of dementia in people with ID. The DSQIID-J is a useful screening tool for dementia in adults with ID.

Validation of the Chinese version of the dementia screening questionnaire for individuals with intellectual disabilities (DSQIID-CV).

BACKGROUND: An increasing number of people with intellectual disabilities (ID) are at risk of developing age-related disorders such as dementia because of a dramatic increase in life expectancy in this population in the recent years. There is no validated dementia screening instrument for Chinese people with ID. The Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) was reported to be a valid, user-friendly, easy-to-use observer-rated instrument. It was developed in the UK and has good psychometric properties. Validation of a Chinese version of the DSQIID will facilitate its application among the Chinese population. METHOD: The DSQIID was translated into the Chinese version (DSQIID-CV). By purposive sampling, service users with ID aged 40 years or over were recruited through two large centres serving adults with ID in Hong Kong. Carers who had taken care of the participants continuously for the past 6 months were invited to complete the DSQIID-CV. All participants were examined by qualified psychiatrists to determine the presence or absence of dementia. RESULTS: Two hundred people with ID whose age ranged between 40 and 73 years (mean 51 years, SD=7.34 years) were recruited to the study. A clinical diagnosis of dementia was established in 13 participants. An overall total score of 22 as a screening cut-off provided the optimum levels of specificity (0.995) and sensitivity (0.923). The DSQIID-CV showed good internal consistency (alpha=0.945) for all its 53 items, and excellent test-retest reliability (0.978, n=46) and inter-rater reliability (1.000, n=47). Exploratory factor analysis resulted in a four-factor solution explaining 45% of the total variance. CONCLUSIONS: The DSQIID-CV is shown to have robust psychometric properties. It is the first valid and reliable dementia screening instrument for Chinese adults with ID.

Primary caregivers' awareness and perception of early-onset dementia conditions in adolescents and young and middle-aged adults with Down syndrome.

The present study aims to investigate the onset of dementia conditions using the Dementia Screening Questionnaire for Individuals with Intellectual Disabilities (DSQIID) scale and to identify the possible factors associated with DSQIID scores in people with Down syndrome (DS). The study population was recruited from the voluntary registry members of the Republic of China Foundation for Persons with Down syndrome; primary caregivers provided DSQIID information on 196 adolescents and adults with DS (aged 15-48 years) who were entered into the database and analyzed using SPSS 20.0 software. The results described the distribution of early-onset dementia conditions in 53 adolescents and adults with DS, and 2.6% of the subjects with DS had possible dementia (DSQIID score ≧ 20). Univariate analyses found that older age (p=0.001) and comorbid conditions (p=0.003) were significantly associated with DSQIID scores. Older subjects were more likely to have higher DSQIID scores than were younger age groups after ANOVA and Scheffe's tests. Lastly, a multiple linear regression analysis revealed that age (p<0.01), severe disability level (p<0.05) and comorbid condition (p<0.01) significantly explained 13% of the variation in DSQIID scores after adjusting for the factors of gender, education level and multiple disabilities in adolescents and adults with DS. The study highlights that future research should focus on the occurrence of dementia in people with DS and on identifying its influencing factors based on sound measurements, to initiate appropriate healthy aging policies for this group of people.

Association of early-onset dementia with activities of daily living (ADL) in middle-aged adults with intellectual disabilities: the caregiver's perspective.

Few studies have investigated in detail which factors influence activities of daily living (ADL) in adults with intellectual disabilities (ID) comorbid with/without dementia conditions. The objective of the present study was to describe the relation between early onset dementia conditions and progressive loss of ADL capabilities and to examine the influence of dementia conditions and other possible factors toward ADL scores in adults with ID. This study was part of the "Healthy Aging Initiatives for Persons with an Intellectual Disability in Taiwan: A Social Ecological Approach" project. We analyzed data from 459 adults aged 45 years or older with an ID regarding their early onset symptoms of dementia and their ADL profile based on the perspective of the primary caregivers. Results show that a significant negative correlation was found between dementia score and ADL score in a Pearson's correlation test (r=-0.28, p<0.001). The multiple linear regression model reported that factors of male gender (ß=4.187, p<0.05), marital status (ß=4.79, p<0.05), education level (primary: ß=5.544, p<0.05; junior high or more: ß=8.147, p<0.01), Down's syndrome (ß=-9.290, p<0.05), severe or profound disability level (ß=-6.725, p<0.05; ß=-15.773, p<0.001), comorbid condition (ß=-4.853, p<0.05) and dementia conditions (ß=-9.245, p<0.001) were variables that were able to significantly predict the ADL score (R(2)=0.241) after controlling for age. Disability level and comorbidity can explain 10% of the ADL score variation, whereas dementia conditions can only explain 3% of the ADL score variation in the study. The present study highlights that future studies should scrutinize in detail the reasons for the low explanatory power of dementia for ADL, particularly in examining the appropriateness of the measurement scales for dementia and ADL in aging adults with ID.