Patterns of offending among people with intellectual disability: a systematic review. Part I: methodology and prevalence data

A systematic review of research on offenders with intellectual disability (ID) was conducted. In the present study, the first of a two‐part presentation of the findings, the authors outline the methodology of the review and present data on the prevalence of offending by adults with ID. The review highlights the methodological problems of the research and the low level of rigour in many of the studies. The organization of the penal and ‘care’ systems are seen to have a huge impact on research findings. In addition, studies which adopt an IQ‐based concept of ID show low rates of offending, whilst those which use wider definitions (e.g. attendance at special school) show higher ones. There is also preliminary evidence for believing that the prevalence of arson and sexual offences may be higher relative to other kinds of crimes for people with ID than for other offenders.     

Patterns of offending among people with intellectual disability: a systematic review. Part II: predisposing factors

In the present study, the second part of a review of offending by adults with intellectual disability (ID), data on predisposing factors are presented and there is a discussion of the overall conclusions. The available data are shown to be problematic in a number of respects: there is no offence‐specific data; and a number of dimensions are under‐explored, specifically race, class and subjective accounts of offenders. Age and gender were the most highly correlated factors, as they are with offenders generally; however, there does appear to be evidence that the average age of offenders with ID is higher than for other offenders. The present authors note with concern the inattention to mainstream criminological research, and a tendency to downplay the extent to which an ‘offender’ is the outcome of complex and multifarious social processes. The authors also argue that the literature is dominated by unsubstantiated assumptions regarding the direction which policy and practice should take.     

Mental health of primary family caregivers with children with intellectual disability who receive a home care programme

Background The aims of the present study were to describe the change in mental health over time in a group of family caregivers with a child with intellectual disability (ID) and to explore the effect of a home care service on the psychological well‐being of the caregiver. Methods The authors identified children with ID who received home care services in the southern part of Taiwan. A total of 46 primary family caregivers (age range = 21–65 years) were recruited for the present study. The study design was a quasi‐experimental follow‐up analysis. The children with ID and their families regularly received home‐based care. The 12‐item version of the Chinese Health Questionnaire (CHQ) was used to evaluate the subjects’ mental health at three time points: (1) baseline, (2) 3 months and (3) 9 months. The validity and reliability of the CHQ have been tested in Taiwan. The Generalized Estimating Equation was used to conduct longitudinal data analyses. Results The authors found that the family caregivers showed a significant improvement in their mental health by month 9. Conclusions The preliminary findings of this study accredit the effect of home care services and suggest that home care services are necessary for family caregivers.     

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.     

Healthcare costs of intellectual disability in the Netherlands: a cost-of-illness perspective

Background Healthcare costs are continuously increasing, and impose a strong responsibility on governments for an adequate allocation of resources among healthcare provisions and patients. Objectives The aims of the present study were to describe the healthcare costs of intellectual disability (ID) and other mental disorders in the context of the total costs of all other diseases, and to determinate the future need of healthcare resources, especially for ID and mental disorders. Methods The present authors performed a top‐down cost‐of‐illness study comprising all healthcare costs of the Netherlands in 1994. Data on healthcare use were obtained for all 22 healthcare sectors, and used to ascribe costs to disease groups, age and sex. Results Costs of mental disorders are by far the largest in the Dutch healthcare system. Some 25.8% of total disease‐specific costs could be ascribed to mental disorders: psychiatric conditions, 10.6%; ID, 9.0%; and dementia, 6.2%. There are large differences between age and sex groups. The costs of ID and schizophrenia are higher among men, and the costs of dementia and depression are higher among women. The age pattern shows two peaks: the first occurs at 25–35 years of age (ID and psychiatric conditions); and the second at 75–85 years of age (dementia). Time trends between 1988 and 1994 show an average annual growth rate of 5.2% for total healthcare costs: psychiatric conditions, 4.8%; ID, 5.4%; and dementia, 9.4%. Demographic projections suggest a less‐than‐average cost increase for ID and psychiatric disorders (with annual growth rates of 0.2% and 0.4%, respectively) compared to the costs of dementia and total healthcare (with annual growth rates of 1.6% and 0.9%, respectively). Conclusions Intellectual disability and mental disorders represent a large part of healthcare use in the Netherlands. The costs will inevitably increase because of the ageing of the population and increasing life expectancy among people with disabilities. Non‐specific cost containment measures may endanger the quality of care for vulnerable people at younger and older ages.     

Defining and applying a functionality approach to intellectual disability

Background The current functional models of disability do not adequately incorporate significant changes of the last three decades in our understanding of human functioning, and how the human functioning construct can be applied to clinical functions, professional practices and outcomes evaluation. Methods The authors synthesise current literature on human functioning dimensions, systems of supports and approaches to outcomes evaluation for persons with intellectual disability (ID), and propose a functionality approach that encompasses a systems perspective towards understanding human functioning in ID. The approach includes human functioning dimensions, interactive systems of supports and human functioning outcomes. Results Based on this functionality approach the authors: (1) describe how such an approach can be applied to clinical functions related to defining ID, assessment, classification, supports planning and outcomes evaluation; and (2) discuss the impact of a functionality approach on professional practices in the field of ID. Conclusions A functionality approach can increase focus on the integrative nature of human functioning, provide unified language, align clinical functions and encourage evidence‐based practices. The approach incorporates a holistic view of human beings and their lives, and can positively affect supports provision and evaluation.     

Autism and intellectual disability: a study of prevalence on a sample of the Italian population

Background In 1994, the American Association on Mental Retardation with the DSM‐IV has come to a final definition of pervasive developmental disorders (PDD), in agreement with the ICD‐10. Prevalence of PDD in the general population is 0.1–0.15% according to the DSM‐IV. PDD are more frequent in people with severe intellectual disability (ID). There is a strict relationship between ID and autism: 40% of people with ID also present a PDD, on the other hand, nearly 70% of people with PDD also have ID. We believe that in Italy PDD are underestimated because there is no agreement about the classification system and diagnostic instruments. Method Our aim is to assess the prevalence of PDD in the Italian population with ID. The Scale of Pervasive Developmental Disorder in Mentally Retarded Persons (PDD‐MRS) seems to be a very good instrument for classifying and diagnosing PDD. Results The application of the PDD‐MRS and a clinical review of every individual case on a sample of 166 Italian people with ID raised the prevalence of PDD in this population from 7.8% to 39.2%. Conclusions The study confirms the relationship between ID and autism and suggests a new approach in the study of ID in order to elaborate a new integrated model for people with ID.     

The development of the QUALITRA‐ID: a user‐orientated interview to assess the quality of care and service trajectories for intellectually disabled persons

Background Care and service trajectories for people with intellectual disabilities (ID) are routes within the healthcare delivery system that consist of all the steps that people with ID and their families have to take in order to realise the needed care and services. In contrast to the growing system‐orientated knowledge concerning quality of care delivered through collaborative relationships between care providers, specific user‐orientated knowledge regarding the quality of care and service trajectories is largely lacking. Aim This article aims to describe the development of the QUALITRA‐ID; a user‐orientated interview concerning the quality of care and service trajectories for people with ID. Methods First, the phenomenon ‘care and service trajectories’ is conceptualised on the basis of document analysis and semi‐structured interviews with key informants in the field of health care for people with ID. Second, the quality of care and service trajectories is operationalised by means of eight focus group discussions with intellectually disabled persons and their parents/relatives and a review of the literature. Third, the QUALITRA‐ID is constructed using the results of the conceptualisation and operationalisation of the phenomenon. Fourth, the QUALITRA‐ID is refined in two stages that were concerned with examining the feasibility, understandability and completeness of the QUALITRA‐ID. The second stage was also concerned with the first quality assessment among people with ID. Results The final result is a 24‐item QUALITRA‐ID consisting of a personal conversation and a closed‐ended part.     

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.     

Challenging behaviours should not be considered as depressive equivalents in individuals with intellectual disability

Background Depression is one of the most common forms of psychopathology in people with intellectual disability (ID). The present study evaluated the utility of an expanded assessment of psychiatric symptoms and challenging behaviours, as measured by the Clinical Behavior Checklist for Persons with Intellectual Disabilities (CBCPID). Methods The CBCPID was administered to 92 people with ID, 35 of whom were diagnosed with a depressive disorder. Results Item and factor analysis of the scale indicated that depression was best assessed using the core DSM‐IV symptoms of depressive disorder. Challenging behaviours such as self‐injury or aggression were not closely associated with depression. Short scales using the core DSM‐IV symptoms of depression were highly internally consistent. There was also evidence of the validity of these scales. Conclusions This study found no evidence that challenging behaviours were depressive equivalents in this population. The present authors conclude that the assessment of depression in people with ID should focus on the core DSM‐IV symptoms of depression.     

Impulsiveness as a factor in sexual offending by people with mild intellectual disability

Background It has been suggested that sexual offending by people with intellectual disability (ID) results from a pattern of impulsive behaviour that is consistent with psychosocial disadvantage, rather than sexual deviancy. This study aimed to explore this hypothesis by assessing levels of impulsiveness in sexual offenders, non‐sexual offenders and non‐offenders with mild ID. Method Impulsiveness was assessed using a modified version of the Barratt Impulsiveness Scale (11th edition). Total impulsivity scores were compared between sexual offenders, non‐sexual offenders and non‐offenders, all with mild ID. Results There was a significant difference in the levels of impulsiveness between sexual offenders and non‐sexual offenders with ID (t = 2.83, P < 0.01). The sexual offenders were less impulsive than non‐sexual offenders. Conclusions This study did not support the hypothesis that sexual offending by people with ID is better explained by impulsive behaviour rather than sexual deviancy. It supports recent findings that among the general population, sexual offenders are less impulsive than controls and violent offenders.     

Prevalence of Helicobacter pylori in people with intellectual disability in a residential care centre in Israel

Background In 1982, Helicobacter pylori (formerly Campylobacter pylori) was identified as a pathogenic factor in peptic ulcer disease by researchers from Australia. Because only a small number of studies of H. pylori infection have been conducted in people with intellectual disability (ID), and none of these were done in Israel, the present authors decided to conduct a pilot study on its prevalence in this population. Methods The Israeli Division for Mental Retardation provides services to over 6000 people in 54 residential care centres (or institutions), and one centre in the south of the country with kibbutz‐style living arrangements was selected for this pilot study. The study was performed as part of the yearly routine medical examination of all residents, and blood specimens were drawn for IgG antibodies to H. pylori (ELISA). Results Out of the 47 individuals screened, 75% (n = 36) were seropositive. Conclusion In addition to the reported high rates of H. pylori infection in residents with ID living in large facilities, the present pilot study suggests that people with ID living in smaller, kibbutz‐style arrangements are also at high risk.     

Use of the Interact Short Form as a tool to evaluate emotion of people with profound intellectual disabilities

Background One of the essential purposes of intervention programmes for people with profound intellectual disabilities (ID) is to enhance the desirable mood and behaviour and decrease the undesirable ones through stabilizing their emotion. There is lack of validated instrument to offer a comprehensive measure that covers the mood and behaviour, both desirable and undesirable, appropriate for people with profound ID. Method This study aimed to examine the validity and reliability of the Interact Short Form for evaluating the mood and behaviour of people with profound ID, and at the same time, review their emotional profile using the Interact Short Form. Both content validity using expert panel review and construct validity by means of factor analysis were investigated. A total of 75 people with profound ID were recruited. Inter‐rater reliability was tested. The results of the Interact Short Form were described to reflect the emotional profile of this group of participants. Results Using the results of expert panel review and those from factor analysis, we found three subscales representing the mood and behaviour of people with profound ID. They were: ‘emotional expression’, ‘interests towards tasks’ and ‘behaviours to environment’. All three subscales were found to be internally consistent (α = 0.71–0.88). The Interact Short Form– People with profound ID version also showed good inter‐rater reliability (mean = 0.72). The results of the Interact Short Form showed that this group of participants had fairly stable emotion under the structured setting and activities in the residential institutions where data were collected. Conclusions The Interact Short Form– People with profound ID version serves as a helpful tool for both clinical and research use in assessing the mood and behaviour of people with profound ID in a simple, comprehensive and systematic way.     

A pilot study of the reliability and validity of the Caregiver Activity Survey – Intellectual Disability (CAS-ID)

Background People with Down's syndrome (DS) are at increased risk of Alzheimer‐type dementia (AD) when compared to the general population. Despite AD being a serious progressive disorder, little attention has been paid to the impact of the illness on formal caregivers. In the general population, the Caregiver Activity Survey (CAS) is used to measure time spent by family caregivers assisting people with AD in their day‐to‐day activities of living. In order to plan appropriate models of health and social care effectively for people with AD and DS, it is imperative that the care requirements of individuals at different stages of dementia are realized. An amended version of this survey, the Caregiver Activity Survey – Intellectual Disability (CAS‐ID), was developed and tested for use by professional caregivers in the present study. Methods The CAS‐ID was administered to 30 people with DS and their caregivers. Convergent validity was tested by comparing the results of the CAS‐ID to other validated tests for cognitive and functional impairment in individuals with DS. Test–retest and inter‐rater reliability were investigated. Results The final version of the CAS‐ID consists of eight items: dressing, bathing/showering, grooming, toileting, eating and drinking, housekeeping, nursing care‐related activities, and supervision/ behaviour management. The scale had excellent test–retest reliability, and correlated strongly with the Down Syndrome Mental Status Examination (DSMSE; r = ?0.770), the Test for Severe Impairment (TSI; r = ?0.881) and the Daily Living Skills Questionnaire (DLSQ; r = ?0.855). Conclusions The present authors provide preliminary evidence for the validity and reliability of the CAS‐ID. This instrument offers a means of identifying and measuring care and resources requirements as this population experiences symptoms of dementia. Such information may help assist healthcare professionals in planning supports and services to address the care challenges evidenced at different stages of the disease process.     

A comparison of offenders with intellectual disability across three levels of security

Background A number of authors have described, with disparate results, the prevalence of people with intellectual disability and their characteristics, in a range of offender cohorts defined by service use. These have included high security, a range of criminal justice services and community services. There is a need for research comparing cohorts of offenders with intellectual disabilities across different settings. Aim and hypothesis To conduct such a comparison and test the hypothesis that severity of characteristics measured will be highest in highest levels of residential security. Method A clinical‐record‐based comparison a offenders with intellectual disability in high security (n = 73), medium/low security (n = 70), and a community service (n = 69). Results Groups were similar in age and tested IQ levels. Early psychiatric service contact had been more likely in the lower security groups. In line with the hypothesis, more complex presentations, in particular comorbid personality disorder, was more likely in the highest security group. Both fatal and non‐fatal interpersonal violence convictions were significantly related to group, with more in the high security group sustaining a conviction both at the index offence and prior to that. Over 50% of all groups had at least one conviction for a sexual offence. A regression model accounting for 78% of the variance was made up largely of disposal variables (Mental Health Act status and probation) and indications of antisocial traits (criminal damage, lifetime conviction for murder and ICD‐10 personality disorder classification). Conclusions and implications for practice The authors show that context of sampling affects most relationships between intellectual disability (ID) and offending when the methods for measuring ID are held constant. The results also present several questions on the relationship between risk, services available in an area and referral to higher security. Copyright © 2006 John Wiley & Sons, Ltd.     

Recruitment to intellectual disability research: a qualitative study

Background Difficulties in the recruitment of adults with intellectual disability (ID) to research studies are well described but little studied. The aim of this study was to investigate the difficulties in recruiting to a specific research project, in order to inform future recruitment to ID research. Methods Individual semi‐structured interviews were held between September 2009 and May 2010 with people who had been involved as intermediaries in recruitment to the research project. These were transcribed verbatim and were independently analysed by two researchers using the Framework approach, who then agreed upon the key emerging themes. Results Ten interviews were analysed. A number of themes arose, including participant factors (interview anxiety, difficulties in understanding the concept of research, worry about negative feedback), the importance of the researcher (using a personal approach, meeting potential participants prior to recruitment) and motivators [enjoyment of the research interview (participant), obtaining a medical assessment (carer)]. The themes were then used to generate strategies to improve recruitment to ID research: these include the research team applying a more personal approach, developing the recruitment process to allow for multiple meetings with potential participants, and considering motivators for both participants and carers. Conclusions This study has used the experiences of intermediaries to identify strategies for improving recruitment to future ID research. This has implications in terms of both time and money. However, successful recruitment is essential to ID research, and we hope that the study will be used by ID researchers to review and improve their recruitment processes.     

Life expectancy of people with intellectual disability: a 35-year follow-up study

A 35‐year follow‐up study based on a nation‐wide population study of the life expectancy of people with intellectual disability (ID) was undertaken. The study population consisted of a total of 60969 person‐years. A prospective cohort study with mortality follow‐up for 35 years was used and the life expectancy of people with ID was calculated for different levels of intelligence. Proportional hazard models were used to assess the influence of level of intelligence and associated disorders on survival. People with mild ID did not have poorer life expectancy than the general population and subjects with mild ID did not have lower life expectancy in the first 3 decades of life. In cases with profound ID, the proportion of expected life lost was > 20% for almost all age groups. The female preponderance was manifested from the age of 60 years onwards, 25 years later than in the general population. Respectively, survival between sexes differed less. Epilepsy and/or hearing impairment increased the relative risk of death for all levels of ID. The prevalence of people with ID over 40 years was 0.4%. People with ID now live longer than previously expected, and the ageing of people with mild ID appears to be equal to that of the general population, posing new challenges to health care professionals.     

Mental disorder in adults with intellectual disability. 1: Prevalence of functional psychiatric illness among a community-based population aged between 16 and 64 years

The reported prevalence of psychiatric illness among adults with intellectual disability (ID) varies widely between 10 and 39%; however, many methodological problems exist. The aims of the present study were to establish the prevalence of functional psychiatric illness among adults with ID who live in the community, in order to compare the overall rate and types of psychiatric illness between the population with ID and the general population without ID, and to establish the risk factors associated with psychiatric illness in adults with ID. The study was done in two stages. In the first part, a trained psychiatrist interviewed 101 randomly selected adults with ID and their carers using the Mini Psychiatric Assessment Schedule for adults with Developmental Disability (Mini PAS‐ADD) to screen for psychiatric caseness. Out of these 101 adults, 90 had sufficient communicative abilities that made the administration of Mini PAS‐ADD possible. A second trained psychiatrist interviewed 19 out of the 20 adults who were diagnosed as psychiatric cases according to the initial Mini PAS‐ADD interview. This psychiatrist interviewed patients and their carers in line with the full PAS‐ADD interview. The second psychiatrist was blind to the initial diagnoses made according to the Mini PAS‐ADD questionnaire. A final psychiatric diagnosis was made according to International Classification of Diseases – 10^th Revision (ICD‐10) criteria. Some 14.4% (95% confidence interval = 7.4–21.4%) of the cohort had a psychiatric diagnosis according to ICD‐10 criteria: 4.4% had schizophrenia, 2.2% depressive disorder, 2.2% generalized anxiety disorder, 4.4% phobic disorder and 1% delusional disorder. The overall rate of functional psychiatric illness (point prevalence) was similar to that found in the general population (16%). However, the rates of schizophrenic illness and phobic disorder were significantly higher in the study cohort compared with those in the general population (0.4% and 1.1%, respectively). Increasing age and the presence of physical disability were significantly associated with the occurrence of psychiatric illness. Out of the 11 remaining adults with severe ID, two (18%) had a diagnosis of a psychiatric illness (one mania and one anxiety disorder) according to the Diagnostic Assessment for the Severely Handicapped (DASH) questionnaire.     

Enhancing staff attitudes, knowledge and skills in supporting the self-determination of adults with intellectual disability in residential settings in Hong Kong: a pretest–posttest comparison group design

Background The ecological perspective recognizes the critical role that is played by rehabilitation personnel in helping people with intellectual disability (ID) to exercise self‐determination, particularly in residential settings. In Hong Kong, the authors developed the first staff training programme of its kind to strengthen the competence of personnel in this area. The purpose of this study was to examine the effectiveness of staff training in enhancing residential staff's attitudes, knowledge and facilitation skills in assisting residents with ID to exercise self‐determination. Methods A pretest–posttest comparison group design was adopted. Thirty‐two participants in an experimental group attended a six‐session staff training programme. A 34‐item self‐constructed scale was designed and used for measuring the effectiveness of the staff training. Results The results showed that the experimental group achieved statistically significant positive changes in all domains, whereas no significant changes were found in the comparison group. Conclusions The findings provided initial evidence of the effectiveness of staff training that uses an interactional attitude–knowledge–skills model for Chinese rehabilitation personnel. The factors that contributed to its effectiveness were discussed and recommendations for future research were made.