A psychometric evaluation of a Swedish version of the psychopathology inventory for mentally retarded adults (PIMRA)

Given the difficulties with symptom identification and the assessment of mental health problems in persons with intellectual disabilities (ID) there has been a focus on the development of relevant assessment schedules for persons with ID. A Swedish version of the psychopathology inventory for mentally retarded adults (PIMRA, informant version), an instrument designed for identification of specific mental health problems in persons with ID, was evaluated in terms of inter-rater reliability, internal consistency, item grouping, criterion and concurrent validity based on a sample of 101 adults with different levels of ID. The Swedish version of the PIMRA had low inter-rater agreement on specific items but good agreement on low or high total score. In order to investigate internal validity, principal component analyses (PCA) were conducted in steps. Consequently, the majority of the 26 items, which remained after three PCA analyses, were grouped in a pattern approximating five of the original PIMRA subscales. The present analysis identified no item grouping matching the original Affective disorder subscale. Based on these results a revised Swedish version was developed. The concurrent validity analysis yielded a strong association between the total scores of the PIMRA and Reiss Screen for Maladaptive Behaviour (RSMB), between subscales on both instruments describing psychotic symptoms and between the RSMB subscale Aggressive behaviour and the PIMRA subscale Adjustment problems. The outcome of the criterion validity analysis indicated that individuals with a clinical diagnosis obtained higher total PIMRA scores than individuals without a clinical diagnosis and a comparison between the PIMRA subscale Psychosis and the clinical diagnosis indicating psychoses according to DSM-III-R or DSM-IV yielded a higher specificity than sensitivity measure. The results indicate that the PIMRA had a potential to identify individuals with mental health problems in persons with different levels (mild, moderate and severe) of ID and identify individuals with a specific mental disorder. Thus, professionals might use the PIMRA as a complement in the diagnostic process.     

The Center for Epidemiologic Studies Depression Scale: factor validity and reliability in a French sample of adolescents with Intellectual Disability

The purpose of this study was to test the factor validity and reliability of the Center for Epidemiologic Studies Depression Scale (CES-D) within a sample of adolescents with mild to moderate Intellectual Disability (ID). A total sample of 189 adolescents (121 boys and 68 girls), aged between 12 and 18 years old, with mild to moderate ID were involved in two studies. In study 1, the content, phrasing and answering format of the CES-D were adapted for adolescents with ID. This instrument was renamed CES-D for ID (CES-D-ID) and two different versions based on two alternative answer scales (Likert and Likert-graphical) were developed and their psychometric properties were verified in study 2. The results provided support for the factor validity, reliability and invariance across gender and age of a 14-item version of the CES-D-ID based on a Likert-graphical answer scale.     

The development of a new measure for the assessment of psychopathology in adults with intellectual disability

Background   People with intellectual disability (ID) and untreated psychiatric disorder lead unnecessarily difficult and unhappy lives. The prevalence of mental illness in children and adults with ID is greater than that found in the general population. A carer-completed checklist of psychopathology that could be used with both children and adults would help identify those individuals with ID most likely to have a mental health problem, help ensure that they receive the limited services that are usually available and also assist the process of clinical assessment, diagnosis and management.
Method   This research aimed to develop a reliable and valid carer-completed checklist of psychopathology for adults with ID by redeveloping an existing measure for children with ID, the Developmental Behaviour Checklist (DBC-P). The new checklist, The Developmental Behaviour Checklist for Adults (DBC-A) was devised by changing, deleting and adding to DBC-P items. Reliability studies were conducted with paid and family carers, and DBC-A scores were compared with the results from two other measures of psychopathology.
Results   One DBC-P item was deleted, seven items changed and 12 items added. The psychometric properties of this new checklist, the DBC for Adults with ID (DBC-A), were investigated and found to be satisfactory. Intraclass correlations for test-retest and inter-rater reliability ranged from 0.72 to 0.85, and concurrent validity with two measures of emotional and behavioural disturbance was satisfactory.
Conclusions   The carer-completed DBC-A provides a broad and comprehensive survey of the emotional and behavioural problems of adults with ID. It has satisfactory psychometric properties and therefore can be used with confidence in clinical, research and service settings, and its development allows continuous assessment of psychopathology across the lifespan for all people with ID.     

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.     

Psychometric evaluation of a Dutch version of the Mini PAS‐ADD for assessing psychiatric disorders in adults with different levels of intellectual disability

Background People with intellectual disabilities (ID) have an increased vulnerability to develop psychiatric problems. Moreover, the early recognition and the accurate diagnosis of psychiatric disorders in the population of persons with ID are challenging. Method A Dutch version of the Mini PAS‐ADD, which is a screening instrument for identification of mental health problems in people with ID, was evaluated in terms of internal consistency, interinformant reliability, item grouping and criterion validity based on a large‐scale random sample (n = 377) and a clinical sample (n = 99) of adults with ID. Results The Dutch version of the Mini PAS‐ADD showed moderate internal consistency, and moderate concordance among informants. Both aspects of the reliability were comparable for different levels of ID. A factor analysis largely confirmed the scale structure. Concurrent validity with the Reiss Screen for Maladaptive Behavior was high for the Depression, Psychosis and Autism scale. The outcome of the criterion‐validity analysis indicated high specificity. The sensitivity for specific psychiatric disorders by the corresponding scales was moderate, but the general sensitivity for the presence of psychopathology on the basis of any of the scales was satisfying. Conclusions The present research reconfirmed the use of the Mini PAS‐ADD as a primary screening device for the identification of mental health problems among people with ID.     

Assessment of Physical Self-Concept in Adolescents with Intellectual Disability: Content and Factor Validity of the Very Short Form of the Physical Self-Inventory

The purpose of this study was to test the factor validity and reliability of the Very Short Form of the Physical Self-Inventory- (PSI-VSF) within a sample of adolescents with mild to moderate Intellectual Disability (ID). A total of 362 ID adolescents were involved in two studies. In Study 1, the content and format scale response of the PSI-VSF were adapted for adolescents with ID. This instrument was thus renamed PSI-VSF-ID and two versions with two alternative responses scales format, were developed: Likert and graphical. In Study 2, results provided support for: (1) the factorial validity and reliability; and (2) factorial invariance across gender, age, type of school placement and ID level of the PSI-VSF-ID associated with a graphical response scale format.     

Construct validity of the Nutrition and Activity Knowledge Scale in a French sample of adolescents with mild to moderate intellectual disability

The purpose of this study was to test the reliability (i.e. internal consistency and test–retest reliability) and construct validity (i.e. content validity, factor validity, measurement invariance, and latent mean invariance) of the Nutrition and Activity Knowledge Scale (NAKS) in a sample of French adolescents with mild to moderate Intellectual Disability (ID). A total sample of 260 adolescents (144 boys and 116 girls), aged between 12 and 18 years old, with mild to moderate ID was involved in two studies. In the first study, analysis of items’ content reveals that many words from the original version were not understood or induced confusion. These items were reworded and simplified while retaining their original meaning. In the second study, results provided support for: (i) the factor validity and reliability of a 15-item French version of the NAKS; (ii) the measurement invariance of the resulting NAKS across genders and ID levels; (iii) the partial measurement invariance of the resulting NAKS across age groups and type of school placement. In addition, the latent means of the 15-item French version of the NAKS proved to be invariant across gender, age categories, and ID levels, but to vary across type of school placement (with adolescents schooled in self-contained classes from regular schools presenting higher levels of NAK than adolescents placed in specialized establishments). The present results thus provide preliminary evidence regarding the construct validity of a 15-item French version of the NAKS in a sample of adolescents with ID.     

Development and preliminary evaluation of a questionnaire on cognitions related to sex offending for use with individuals who have mild intellectual disabilities

Background A number of authors note that distorted cognitions may play a significant role in sex offending behaviour in both the people with intellectual disability (ID) and general populations. However, no scales have been specifically developed for use with individuals with ID. To date, there is no valid, reliable, self‐report questionnaire that assesses cognitive factors in these individuals. This paper aims to develop a valid, reliable self‐report questionnaire to assess antisocial attitudes consistent with sex offending behaviour in individuals who have mild ID. Methods Seventeen male individuals with ID who had sexually offended were compared with two non‐sex offender groups: 19 males with and 36 males without ID. The Questionnaire on Attitudes Consistent with Sex Offending (QACSO) measure was used to establish sexual attitudes in the three groups. The reliability and validity of the QACSO was examined. Results The groups were compared and results demonstrated that the QACSO is a promising tool in terms of providing an internally consistent, reliable and valid indicator of cognitive distortions/attitudes held by sex offenders with ID. Conclusions The limitations, suggestions for modification, potential uses of the questionnaire and directions for further research are proposed.     

Quality of life assessment in intellectual disabilities: The Escala Pessoal de Resultados versus the World Health Quality of Life-BREF

The aim of this study is to compare the applications of the Escala Pessoal de Resultados (EPR) and the World Health Quality of Life-BREF (WHOQOL-BREF) in quality of life (QOL) assessment of people with intellectual disabilities (ID). A total of 216 adults with ID were assessed (age ranging from 18 to 64 years; 128 people were diagnosed with mild, and 88 with moderate ID). The two scales were administered to each person to obtain their perception about their QOL. Statistically significant correlations (weak to moderate) were observed between both scales. The EPR and the WHOQOL-BREF demonstrated adequate reliability, construct, and discriminant validity in our sample. However, the group of adults with moderate ID scored higher on the WHOQOL-BREF than on the EPR. Results indicated that the two assessment instruments aim to evaluate different measures, and seem to be not interchangeable.     

Psychometric comparisons of three measures for assessing motor functions in preschoolers with intellectual disabilities

Background Deficit in motor performance is common in children with intellectual disabilities (ID). A motor function measure with sound psychometric properties is indispensable for clinical and research use. The purpose of this study was to compare the psychometric properties of three commonly used clinical measures for assessing motor function in preschoolers with ID: the Bruininks‐Oseretsky Test of Motor Proficiency‐Second Edition, the Movement Assessment Battery for Children‐Second Edition and the Peabody Developmental Motor Scale‐Second Edition (PDMS‐2). Method One hundred and ninety‐one children aged 3–6 years with ID were evaluated with the three measures at three time points: two baseline measurements with a 1‐week interval before the intervention, and a follow‐up measurement after 6 months of paediatric rehabilitation programme. One hundred and forty‐one participants completed all of the assessments. The distribution (ceiling and floor effects) and reliability (internal consistency and test–retest reliability) of each measure were examined. Concurrent validity, predictive validity, and responsiveness were examined as well. Results All measures, except for the PDMS‐2, had significant floor effects or ceiling effects at one or more time points. The three measures had good internal consistency (Cronbach α ≥ 0.86) and test–retest reliability (intraclass correlation coefficient ≥ 0.96). The Spearman ρ correlation coefficient for each pair of the three measures was ≥0.80, indicating high concurrent validity. The predictive validity of the three measures was satisfactory (Spearman ρ ≥ 0.52). The responsiveness of the three measures was moderate (0.47 ≤ effect size ≤ 0.74). The minimal detectable changes of the three measures were satisfactory. Conclusions All three measures showed sufficient reliability, validity and responsiveness in preschoolers with ID, but the PDMS‐2 is recommended for its superior psychometric properties.     

Psychometric evaluation of a self-report measure of depression for individuals with mental retardation

The psychometric properties of the Self-Report Depression Questionnaire (SRDQ) were evaluated, extending a previous assessment of this instrument. Data from two independent studies (Esbensen, 2004; Seltzer & Krauss, 1989) were pooled to generate a sample of 192 individuals with primarily mild or moderate mental retardation. Reliability estimates of this questionnaire were good to excellent and corroborated prior findings. In addition, the measure was found to have sound validity as evidenced by convergent validity, discriminant validity, and predictive validity and by comparing individuals with and without clinical diagnoses of depression. Thus, the SRDQ appears to be a reliable and valid measure of depressive symptomatology for individuals with mild or moderate mental retardation. Screening procedures are suggested.     

Examination of adaptive behavior differences in adults with autism spectrum disorders and intellectual disability

Autism spectrum disorders (ASD) and intellectual disabilities (ID) are high prevalence developmental disabilities that co-occur at high rates. Furthermore, Axis I psychopathology is known to occur more frequently in individuals with ID than the general population. The problems are lifelong and can be major impediments to independent living. Despite this, little research with adults is available to determine the effects of these disabilities on specific adaptive skills. In this study, 337 adults were evaluated using the Vineland Adaptive Behavior Scale to assess the effects of these disabilities on looking at an ID, ID plus ASD, and ID and ASD plus Axis I psychopathology group. Adaptive skills were greatest for the ID group followed by the ID plus ASD, and ID and ASD plus psychopathology. Thus, the more handicapping conditions, the greater the skills deficits observed, particularly where psychopathology was concerned. As such, accurately identifying the causes of adaptive skill deficits will likely result in more precise and effective treatment.     

The validity of the autism spectrum disorders-diagnosis for intellectually disabled adults (ASD-DA)

Psychologists interviewed direct-care staff using a battery of assessment measures including the autism spectrum disorders-diagnosis for intellectually disabled adults (ASD-DA), the Diagnostic Assessment for the Severely Handicapped-II (DASH-II), the Matson Evaluation of Social Skills for Individuals with Severe Retardation (MESSIER), the Socialization domain of the Vineland Adaptive Behavior Scales (VABS), and a checklist containing criteria for autism and PDD-NOS from the DSM-IV-TR and ICD-10. Three hundred and seven intellectually disabled (ID) adolescents and adults ranging in age from 16 to 88 were assessed. Participants were diagnosed with either ID and ASD (autism or PDD-NOS; n=156) or ID and no Axis I diagnosis (n=151). A modification of the multitrait-multimethod approach was used to establish the convergent and discriminant validity of the ASD-DA. The scale proved to have robust convergent validity when correlated with the DSM-IV-TR/ICD-10 checklist, MESSIER, and Socialization domain of the VABS. Additionally, discriminant validity was demonstrated by comparing the ASD-DA to items from the DASH-II (measure of general psychopathology). The implications of these data are discussed.     

Clinical outcomes of a specialised inpatient unit for adults with mild to severe intellectual disability and mental illness

Background   Limitations of general psychiatric services have led to the development of specialised psychiatric programmes for patients with intellectual disability (ID) and mental health needs. Few studies have examined treatment outcomes of specialised inpatient units, and no studies have explored how the effects of intervention may differ for individuals at varying levels of cognitive ability. The present study examined clinical outcomes of inpatients with mild ID in contrast to inpatients with moderate to severe ID within the same service.
Method   Thirty-three patients (17 with mild ID and 16 with moderate to severe ID) discharged between 2006 and 2008 from a specialised inpatient unit in Canada for adults with ID and mental illness were studied. In addition to examining change in scores on clinical measures, outcomes with regard to length of stay, diagnostic change, residential change and re-admission to hospital were explored.
Results   Both groups demonstrated clinical improvement from admission to discharge. However, only patients with mild ID demonstrated improvements on the Global Assessment of Functioning.
Conclusions   This study is one of the first to consider outcomes of higher and lower functioning individuals with ID on a specialised inpatient unit. Results suggest that outcomes may be different for these groups, and some clinical measures may be more sensitive to changes in patients with more severe disabilities.     

Validity and reliability of the Spanish version of the diagnostic assessment for the severely handicapped (DASH-II)

Background and objectivesThe DASH-II scale is a specific instrument for measuring psychopathological symptoms in people with severe and profound intellectual disability (ID). The aim of the study is the validation of the Spanish version, evaluating its reliability and validity. At the same time we examine the prevalence of mental disorders in our sample.Material and methodsTwo reviewers independently passed the Spanish version of the DASH-II (DASH-II-S) to 83 users to establish inter-rater reliability. To assess inter-rater reliability or test–retest reliability, fifty participants were reassessed by the same rater within 7 days.ResultsDASH-II-S showed good internal consistency (Cronbach's α = 0.879) and good reliability, both intra and inter-rater reliability. The prevalence of psychopathology in the sample is 94%, and the use of psychotropic drugs is also high, with 61.4% receiving one or more antipsychotics.ConclusionsDASH-II-S is a valid and reliable instrument that can be used for the assessment of psychopathology in people with ID. The translated version retains the psychometric properties of the original English version. Moreover, the high prevalence of mental disorders in this population may explain the widespread use of psychotropic drugs, but it forces us to continuous reassessment and justification.     

Effects of an exercise programme on anxiety in adults with intellectual disabilities

Although high anxiety is common in people with intellectual disabilities (ID) and the anxiolytic effects of exercise have been systematically recognised in clinical and non-clinical populations, research is scant concerning the role played by exercise on anxiety in people with ID. The purpose of this study was to investigate the effects of a 12-week exercise programme on anxiety states in a group of adults with ID. Twenty-seven individuals with mild to moderate ID were randomly assigned to an exercise group or a control group. The Zung Self-Rating Anxiety Scale adapted for individuals with ID and the State-Trait Anxiety Inventory form Y were used to assess trait and state anxiety. In comparison with the control group, the anxiety scores of people in the exercise group decreased significantly over time.     

Rasch analysis of the Developmental Test of Visual-Motor Integration in children with intellectual disabilities

The purpose of this study was to examine the measurement properties of the Developmental Test of Visual-Motor Integration (VMI) in children with intellectual disabilities (ID) ages 4–12 years using the dichotomous Rasch model. The VMI was administered individually to 454 children with ID. Rasch analysis was applied to investigate unidimensionality, item fit to the model, differential item functioning (DIF), and item targeting. Discriminative validity was obtained by receiver operating characteristic (ROC) curve analysis. Items were eliminated if the task was too easy or too difficult, or showed misfit to the Rasch model. The remaining items fitted the unidimensional construct the test was intended to measure and were free of DIF. The Rasch reduced version of the VMI with 9 items appeared to be suited to measure mild degrees of perceptual-motor impairment and demonstrated excellent reliability (0.91). VMI-9 had a larger area under the ROC curve in its ability to differentiate mild versus moderate to severe ID compared with the original version. Taken together, the VMI-9 provides a quick, reliable and valid measure for screening and identifying perceptual-motor deficits in children with ID.     

Psychometric properties of the Aberrant Behavior Checklist, the Anxiety, Depression and Mood Scale, the Assessment of Dual Diagnosis and the Social Performance Survey Schedule in adults with intellectual disabilities

Progress in clinical research and in empirically supported interventions in the area of psychopathology in intellectual disabilities (ID) depends on high-quality assessment instruments. To this end, psychometric properties of four instruments were examined: the Aberrant Behavior Checklist (ABC), the Assessment of Dual Diagnosis (ADD), the Anxiety, Depression and Mood Scale (ADAMS), and the Social Performance Survey Schedule (SPSS). Data were collected in two community-based groups of adults with mild to profound ID (n = 263). Subscale reliability (internal consistency) ranged from fair to excellent for the ABC, the ADAMS, and the SPSS (mean coefficient α across ABC subscales was .87 (ranging from fair to excellent), the ADAMS subscales .83 (ranging from fair to good), and the SPSS subscales .91 (range from good to excellent). The ADD subscales had generally lower reliability scores with a mean of .59 (ranging from unacceptable to good). Convergent and discriminant validity was determined by bivariate Spearman ρ correlations between subscales of one instrument and the subscales of the other three instruments. For the most part, all four instruments showed solid convergent and discriminant validity. To examine the factorial validity, Confirmatory Factor Analyses (CFA) were attempted with the inter-item covariance matrix of each instrument. Generally, the data did not show good fits with the measurement models for the SPSS, ABC, or the ADAMS (CFA analyses with the ADD would not converge). However, most of the items on these three instruments had significant loadings on their respective factors.     

The Diagnosis of Depression in People with Severe Limitations in Intellectual Functioning

People with intellectual disability (ID) were once considered immune to developing psychopathology, including affective disorders such as depression. Now research has shown that people with ID do suffer from depression, and the focus is on understanding how to best diagnose and provide treatment. Research has come a long way in adapting the diagnostic process for people with mild/moderate deficits in intellectual functioning and communication abilities. However, there is a lack of research and clinical understanding regarding how to assess depression in people who lack communication skills and function with severe or profound deficits in intellectual functioning. This paper reviews the available literature on the occurrence of depression in people with ID, specifically those with more significant deficits, and discusses the difficulties that arise in trying to determine a diagnosis of depression for this population.