Heleen M. Evenhuis

Prevalence of visual impairment in adults with intellectual disabilities in the Netherlands: Cross-sectional study

PurposeTo obtain the first representative and valid population-based prevalence figures on visual impairment and blindness in adults with intellectual disabilities (ID) and to identify risk groups.MethodsStudy design: Cross-sectional survey. An age-Downs syndrome-stratified random sample of 1598 persons from a base population of 9012 adult users of ID services with mild to profound intellectual disabilities was screened. Participants underwent protocollised on-site screening of visual functions. Results were related to degree of ID, occurrence of Downs syndrome (DS) and age. Main outcome measure: Prevalences of visual impairment and blindness in the study population and in subgroups and weighted prevalences in the total Dutch population using ID services.ResultsPrevalences of visual impairment ranged from 2.2% (95% confidence interval (CI), 0.5–6.4) in young adults with mild ID and no Downs syndrome to 66.7% (95% CI, 41.0–86.7) in older adults with profound ID and Downs syndrome; prevalences of blindness ranged from 0.7% (95% CI, 0.1–4.1) to 38.9% (95% CI, 28.1–50.3). Weighted prevalences of visual impairment and blindness in the total Dutch population of adult users of intellectual disabity services are 13.8% (95% CI, 9.3–18.4) and 5.0% (95% CI, 3.8–6.2), respectively. Prior to this study, visual impairment or blindness had remained undiagnosed in 106/261 (40.6%) persons.ConclusionsAs compared to published figures for the general Dutch population aged 55 years and over (visual impairment 1.4%, blindness 0.5%), prevalences of visual impairment and blindness are higher in all subgroups with intellectual disabilities, including the young and mildly handicapped group. The diagnosis is too often missed. All persons with severe or profound intellectual disabilities, and all older adults with Downs syndrome, should be considered visually impaired until proved otherwise.

Multimorbidity in older adults with intellectual disabilities

Multimorbidity may be related to the supposed early aging of people with intellectual disabilities (ID). This group may suffer more often from multimorbidity, because of ID-related physical health conditions, unhealthy lifestyle and metabolic effects of antipsychotic drug use. Multimorbidity has been defined as two or more chronic conditions. Data on chronic conditions have been collected through physical assessment, questionnaires, and medical files. Prevalence, associated factors and clusters of multimorbidity have been studied in 1047 older adults (≥ 50 years) with ID. Multimorbidity was prevalent in 79.8% and associated with age and severe/profound ID. Four or more conditions were prevalent in 46.8% and associated with age, severe/profound ID and Down syndrome. Factor analyses did not reveal a model for disease-clusters with good fit. Multimorbidity is highly prevalent in older adults with ID. Multimorbidity should receive more attention in research and clinical practice for targeted pro-active prevention and treatment.

Characteristics of instruments screening for depression in adults with intellectual disabilities: Systematic review

The aim of this study was to obtain information on feasibility, reliability and validity of available instruments screening for depression applied in people with intellectual disabilities (ID). Therefore, literature was systematically reviewed. For self-report, the Glasgow Depression scale for people with a Learning Disability appears most promising (internal consistency α=0.90, test-retest reliability r=0.97, sensitivity 96% and specificity 90%). For informant-report three instruments seem promising: the Assessment of Dual Diagnosis (internal consistency α=0.77 and α=0.91, test-retest reliability r=0.94, interrater reliability r=0.98), the Reiss Screen for Maladaptive Behaviour (internal consistency α=0.58-0.83, interrater reliability r=0.61-0.84, sensitivity 80%, specificity 83%), and the Childrens Depression Inventory (internal consistency α=0.86, sensitivity 83%, specificity 93%). None of these three instruments have been studied satisfactorily in this group, yet. More research on psychometric properties, especially sensitivity and specificity in the ID population, is needed.

Prevalence of depression and anxiety in older users of formal Dutch intellectual disability services.

BACKGROUNDnLittle is known about the prevalence of depression and anxiety among older people with intellectual disabilities (ID). Therefore, the aim of this study was to study the prevalence of depression and anxiety in this population.nnnMETHODnThis study is a cross-sectional epidemiologic multicentre study which was part of the Healthy Ageing and Intellectual Disabilities study. The study population consisted of 990 participants aged ≥50 years with borderline to profound ID which were screened with self-report and informant-report instruments; 290 of them were assessed with a standardized diagnostic interview.nnnRESULTSnDepressive symptoms were prevalent in 16.8% (95% CI: 14.4-19.1) and significantly associated with higher age. Anxiety symptoms were prevalent in 16.3% (95% CI: 14.0-18.6) and significantly associated with female gender and borderline to mild ID. Major depressive disorder was prevalent in 7.6% (95% CI: 5.2-11.0), anxiety disorders in 4.4% (95% CI: 2.6-7.0) and both in 0.7% (95% CI: 0.2-1.6). There was no relationship with gender, age or level of ID.nnnLIMITATIONSnFor most participants, informant-report instruments have been used instead of self-report to overcome communication difficulties or inabilities. Also, a standardized psychiatric diagnostic interview has been used instead of psychiatric diagnoses made by an experienced psychiatrist.nnnCONCLUSIONnPrevalence of major depressive disorder is higher and of anxiety disorders lower than in the Dutch general older community-dwelling population.

Instruments assessing anxiety in adults with intellectual disabilities: A systematic review

BACKGROUNDnIn the last decades several instruments measuring anxiety in adults with intellectual disabilities have been developed.nnnAIMnTo give an overview of the characteristics and psychometric properties of self-report and informant-report instruments measuring anxiety in this group.nnnMETHODnSystematic review of the literature.nnnRESULTSnSeventeen studies studying 14 different instruments were found. Methodological quality as measured with the Quality Assessment of Diagnostic Accuracy Studies checklist was insufficient for four studies, sufficient for seven, and good for six. For self-report, the Glasgow Anxiety Scale for people with a learning disability appears most promising, with good internal consistency (a = 0.96), high test-retest reliability (r = 0.95), sensitivity (100%) and specificity (100%). For informant-report, the general anxiety subscale of the Anxiety, Depression and Mood Scale may be promising, with good internal consistency (a = 0.83 and a = 0.84) and excellent test-retest reliability (ICC = 0.78 and ICC = 0.92), but poor interrater reliability (ICC = 0.39).nnnCONCLUSIONSnTwo instruments appear promising. However, these instruments have only been studied once or twice, whereas the methodological quality of these studies was varying.

Metabolic syndrome in 25% of older people with intellectual disability

BACKGROUNDnLife expectancy of people with intellectual disabilities (IDs) is rapidly normalizing, as are prevalences of age-related cardiovascular disease in this group. We investigated the prevalence of the metabolic syndrome in the older population with ID and associations with patient characteristics.nnnMETHODSnPrevalence of the metabolic syndrome, according to National Cholesterol Education Program-Adult Treatment Panel III criteria, was assessed with standardized physical examinations in 470 Dutch adults with ID, aged ≥50 years, who receive residential care from three Dutch care providing organizations. Because of skewing towards an overrepresentation of females and more moderate to severe ID in the study population, reweighting was applied to obtain a representative population prevalence. Correlations with patient characteristics were analysed with logistic regression analyses.nnnRESULTSnFour hundred and twelve participants completed all assessments. The weighted prevalence of the metabolic syndrome was 25.1% [95% confidence interval (CI) 21.0-29.3%], with a significantly higher risk for people with mild ID.nnnCONCLUSIONSnThe prevalence of the metabolic syndrome in the population with ID is significantly higher than that in the general Dutch population aged ≥50 years (15.7%, 95% CI 13.5-17.9%).

Visual performance in specific syndromes associated with intellectual disability

Purpose To report visual performance in adults with specific causes of intellectual disability (ID) and to compare the test results to published reports. Methods In a large-scale multicenter epidemiologic study of sensory impairments in 1598 adults with ID, the authors performed ocular assessments in 1539 persons. They compared the test results of those with five specific genetic disorders (Angelman syndrome, Prader-Willi syndrome, fragile X syndrome, Williams-Beuren syndrome, and tuberous sclerosis). Results An overrepresentation of strabismus, low vision, and refractive errors was found. Apart from fragile X syndrome and Prader-Willi syndrome (with in general mild to moderate ID), the other syndrome groups contained one or more subjects with visual impairment or blindness. A number of them had never been seen by an ophthalmologist. Conclusions The authors confirm a number of ocular features previously reported by other studies and suggest some additional ocular features. They found increased frequencies of treatable ophthalmologic conditions in the subgroups. Because reliable ocular assessment is feasible for 85% of persons with ID, the results are an incentive to address visual functioning in people with ID in order to correct ocular problems and maximize their possibilities.

Life events and their associations with depression and anxiety in older people with intellectual disabilities: Results of the HA-ID study

BACKGROUNDnPeople with intellectual disabilities (ID) may be exposed to more life events due to different living circumstances and limited coping abilities. The frequency of life events may increase with age due to age-related decline, loss of significant others and forced relocations. We studied the occurrence of life events in adults with mild to profound ID aged ≥ 50 years and their association with depression and anxiety.nnnMETHODSnOccurrence and burden of life events were assessed with a checklist of 28 items, completed by professional caregivers. Depression and anxiety were assessed with self-report and informant-report screening instruments (n=988) and with a psychiatric interview (n=286). Associations with depression and anxiety were studied for life events in general and for specific life events.nnnRESULTSn97% of the participants had been exposed to multiple life events during the preceding year and 72% had been exposed to one or more negative life events. The frequency was significantly higher in participants aged 65 years or over, in participants with mild or moderate ID and in participants with depression or anxiety. Minor physical illness and problems with a fellow resident were significantly associated with depression and anxiety, decline or loss of mobility and loss of leisure-time activities with depression and change at work or from work with anxiety.nnnLIMITATIONSnThis study was cross-sectional and therefore lacks reliable information about causality.nnnCONCLUSIONSnGiven the high prevalence of life events and their association with depression and anxiety, life events should be better monitored and, if possible, prevented.

Frailty and intellectual disability: A different operationalization?

Frailty is increasingly being recognized as a relevant health measure in older populations, associated with an increased risk of adverse health outcomes and care dependency. Because it is generally perceived that people with intellectual disabilities are old from age 50 onwards, frailty research in this group might lead to an understanding of factors, contributing to this perception. The development since the 1990s of conceptual and operational definitions of frailty has resulted in different approaches: biological (phenotype), multidimensional, and non-specific deficit accumulation. All approaches consider disability a consequence rather than a cause of frailty. This may be different for long-disabled populations, which would have consequences for validity of frailty measures. First research shows that the different approaches are applicable to study populations with intellectual disabilities as well. Frailty as defined by both the phenotypic and deficit accumulation approach appears to develop considerably earlier and is more severe in people with intellectual disabilities than in the general older population, supporting the notion of early aging. Before any clinical implications can be outlined, health outcomes (validity), causes, and prevention of frailty should be investigated.

Feasibility, reliability and validity of the Dutch translation of the Anxiety, Depression And Mood Scale in older adults with intellectual disabilities

BACKGROUNDnThe informant-based Anxiety, Depression And Mood Scale was translated into Dutch and its feasibility, reliability and validity in older adults (aged ≥ 50 years) with intellectual disabilities (ID) was studied.nnnMETHODnTest-retest (n = 93) and interrater reliability (n = 83), and convergent (n = 202 and n = 787), discriminant (n = 288) and criterion validity (n = 288) were studied. Convergent and criterion validity were studied for the Depressed mood and General anxiety subscales. Subgroups based on level of ID and autism have been made to study the criterion validity. Psychiatric diagnoses based on the PAS-ADD Interview were used as gold standard.nnnRESULTSnAll subscales had good internal consistency (α ≥ 0.80), excellent test-retest reliability (ICC ≥ 0.75) and good interrater reliability (ICC ≥ 0.74), except for the Social avoidance subscale (ICC = 0.57). The Depressed mood subscale showed low correlation (r = 0.44) with the self-report Inventory of Depressive Symptomatology, high correlation with the informant-report Signalizing Depression List for people with ID (r = 0.71) and no correlation with the PAS-ADDs sleep disorders subscale (r = 0.15). Its sensitivity ranged from 73 to 80%, and its specificity from 71 to 79%. The General anxiety subscale showed low correlation with the self-report scales: Glasgow Anxiety Scale (r= 0.37) and Hospital Anxiety and Depression Scale (r = 0.41), and no correlation with the sleep disorder subscale (r = 0.02). Its sensitivity ranged from 67 to 100%, and its specificity from 48 to 81%.nnnCONCLUSIONSnThe Dutch translation of the ADAMS is reliable and sufficiently valid to screen for anxiety and depression in older people with ID.