A Review of Global Literature on Using Administrative Data to Estimate Prevalence of Intellectual and Developmental Disabilities

Reproductive health of women with intellectual disability: antenatal care, pregnancies and outcomes in the Dutch population

BACKGROUND

Research in a handful of countries found that women with intellectual disability (ID) faced barriers and risks regarding antenatal care and reproductive health. This study tested disparities between women in the Netherlands with and without ID in antenatal care, pregnancy rates and pregnancy outcomes.

METHODS

Secondary analyses on the large representative panel of primary health patients in the Netherlands by the Netherlands Institute for Health Services Research (NIVEL) compared women in their reproductive age (18-49 years) with (n = 2397) and without (n = 228 608) indicators of ID. Bias due to underreporting and under-identification was reduced by linkage with an index of ID for the total Dutch population from Statistical Netherlands.

RESULTS

Women with ID were more likely to receive contraceptive care [95% confidence interval (CI) for odds ratio (OR) = 1.37-1.61] and became somewhat more often pregnant (95% CI OR = 1.06-2.30) than women from the general population, adjusting for age difference and follow-up time. No statistical differences were found in medical complications during pregnancy, delivery and immediately after birth, but women with indicators of ID had a higher risk of losing their pregnancy, including through induced abortion (95% CI OR = 1.26-1.99).

CONCLUSIONS

Women with ID have specific needs around contraceptive care and risks around their pregnancy that may require more awareness among practitioners and better understanding of the processes of care and decision-making.

Significant regional inequalities in the prevalence of intellectual disability and trends from 1990 to 2019: a systematic analysis of GBD 2019

AIMS

Policymakers and researchers have little evidence on prevalence rates of intellectual disability (ID) or their changes over time to tailor healthcare interventions. Prevalence rates and trends of ID are especially lacking in regions with lower socio-demographic development. Additionally, the assessment of inequalities in the prevalence of ID across regions with varying socio-demographic development is understudied. This study assessed variations in prevalence rates of ID from 1990 to 2019 and the related inequalities between low and high socio-demographic index (SDI) regions.

METHODS

This study used global data from 1990 to 2019 for individuals with ID from the 2019 Global Burden of Diseases study. Data analyses were performed from September 2021 to January 2022. Prevalence for individuals with ID was extracted by sex, age groups and SDI regions. Annual percentage change (APC) was estimated for each demographic group within SDI regions to assess their prevalence trends over 30 years. Relative and absolute inequalities were calculated between low and high SDI regions for the various age groups.

RESULTS

In 2019, there were 107.62 million (1.74%) individuals with ID, with an APC of -0.80 (-0.88 to -0.72). There was a slightly higher prevalence among males (1.42%) than females (1.37%). The highest prevalence rates were found in the low-middle SDI regions (2.42%) and the lowest prevalence rates were in the high SDI regions (0.33%). There was a large reduction in the prevalence rate between the youngest age group v. the oldest age group in all the SDI regions and at all time points. The relative inequalities between low and high SDI regions increased over three decades.

CONCLUSIONS

While an overall decrease in global prevalence rate for ID was found, relative inequalities continue to increase with lower SDI regions needing more comprehensive support services. The demographic trends indicate a significantly higher mortality rate among those with ID v. the rest of the population. Our study highlights the necessity for policies and interventions targeting lower SDI regions to mobilise resources that better support individuals with ID and achieve sustainable development goals proposed by the United Nations.

Efficacy of Healthy Aging Interventions for Adults With Intellectual and Developmental Disabilities: A Systematic Review

BACKGROUND AND OBJECTIVES

There is a lack of information on intervention strategies employed for health promotion and disease prevention for older adults with intellectual and developmental disabilities (IDDs), who usually experience poorer health compared to their peers without IDDs. We carried out the first systematic review to scrutinize the impact of intrinsic factors (e.g., cognitive, mental, and physical health) on the health status of older adults with IDDs.

RESEARCH DESIGN AND METHODS

To assess the efficacy of such interventions, we examined 23 articles including prospective "healthy aging" interventions designed for adults with IDDs. Searches were carried out in the databases Web of Science, Scielo, and PsycINFO in April 2020. Articles were organized in thematic areas: (a) physical activity and health nutrition (n = 10), (b) health education and health screening (n = 6), (c) social inclusion and community participation (n = 3), and (d) multicomponents (n = 4). Except for 5 randomized controlled trial studies, the designs were mainly nonrandomized, involving small sample sizes (Nrange = 8-379 participants), and lacking follow-up.

RESULTS

The studies included 2,398 men and women with IDDs (ranging in age from 18 to 86 years [mean age: 44.3 years]). Overall, intervention outcomes were mostly positive; however, some negative outcomes were reported.

DISCUSSION AND IMPLICATIONS

In brief, healthy aging interventions for people with IDDs remain scarce, incipient, and sporadic. We recommend that more attention needs to be given to active health promotion with people with IDDs as a program practice among organizations and as a focal public policy among governments.

Invisible populations: Who is missing from research in intellectual disability?

It is estimated that approximately 41% of adults with intellectual and developmental disability (IDD) are served through the developmental disabilities (DD) system in the US. The remaining 59% include individuals who meet diagnostic criteria but are not actively receiving paid services or may not be known to the DD system. Scholars have referred to this group as the "hidden majority." Very little is known about the health and well-being of these adults. It remains to be seen if the hidden majority is comparably susceptible to mental health difficulties, given how little is known about this population by DD systems. The purpose of this manuscript is to highlight where one may identify individuals belonging to this hidden population and how researchers might effectively recruit from this group so as to ensure more representative samples of all people with IDD.

Using linked administrative data to determine the prevalence of intellectual disability in adult prison in New South Wales, Australia

BACKGROUND

Studies of the representation of people with intellectual disability (ID) in custody report widely inconsistent findings that reflect variation in how ID is defined and the methods employed for identification. Using linked administrative data may be of utility in studies of the representation of people with ID in custody. However, this approach requires an understanding of the purpose of and factors influencing identification in disparate administrative datasets.

METHODS

This study uses linked administrative data encompassing disability, health and corrections data for the year 2014 to estimate the prevalence of ID in adult custody and explore how ID representation within administrative data impacts prevalence estimates and what patterns of identification reveal about support service access for this group.

RESULTS

This study finds that 4.3% of the New South Wales adult custody population had an identified ID. Prisoners with ID were younger, more likely to have had a previous custodial episode and more likely to be Indigenous than the general prison population. Identification of ID across linked administrative datasets is uneven, which, if used in isolation, would result in variation in prevalence estimates according to source data.

CONCLUSIONS

The utilisation of linkage data from a broad range of health and support services including custody offers a comprehensive identification methodology. Inconsistency in the identification of ID across datasets indicates a potential disjuncture between prisoners with ID and support services, which may have relevance for efforts to reduce reincarceration of those in this population.

Linking national public services data to estimate the prevalence of intellectual disabilities in The Netherlands: results from an explorative population-based study

OBJECTIVES

Individuals with intellectual disabilities (ID) depend on public services for daily support and medical care; however, this group of individuals can be difficult to identify within population data. This therefore limits the opportunities to accurately estimate the size of the population with ID, monitor trends and tailor public health interventions according to the needs and characteristics of this group. By linking relevant databases, this study sought to identify individuals with ID in national data, to estimate the prevalence of ID based on public service use and to explore how this method can be used to better monitor the population with ID.

STUDY DESIGN

Explorative data linkage study using the Dutch population register and databases from public services accessible with an ID diagnosis.

METHODS

The overall prevalence of ID in the Dutch adult population was estimated, specified by age group and sex, and the identified ID groups were also characterised by their support needs. Participants included the entire adult Dutch population who were alive on 1 January 2015.

RESULTS

After linking databases, 187,149 adults with ID were identified within a population of almost 12.7 million Dutch adults, giving an ID prevalence estimate of 1.45%. Prevalence of ID was higher among males (1.7%) than females (1.2%). Most individuals with ID were identified through the use of residential care services (n = 91,064; 0.7%). Non-residential ID-related care was used by 27,007 individuals (0.2%). Social, employment or income support due to a (mild) ID was received by 69,078 individuals (0.5%); the mean age in these ID groups was between 8 and 10 years which is younger than that in the general Dutch population. ID prevalence declined with increasing age across all ID subgroups.

CONCLUSIONS

The ID prevalence in The Netherlands, as determined by ID-related public service usage, aligns with international estimates. This suggests that national supportive services are accessible and used by individuals with ID. Moreover, this demonstrated that databases from national supportive services can be a useful resource to identify individuals with ID at the population level and can enable structural monitoring of the ID population through linking national databases.

COVID-19 IDD: A global survey exploring family members' and paid staff's perceptions of the impact of COVID-19 on individuals with intellectual and developmental disabilities and their caregivers

Background: This protocol outlines research to explore family members' and paid staff's perceptions of the impact of COVID-19 on individuals with intellectual and developmental disabilities and their caregivers. Evidence suggests that people with intellectual and developmental disabilities experience disparities in healthcare access and utilisation. This disparity was evident early in the pandemic when discussions arose regarding the potential exclusion of this population to critical care. Methods: An anonymous online survey will be conducted with caregivers, both family members and paid staff, to explore their perceptions of the impact of COVID-19 in terms of demographics, living arrangements, access to services, social distancing, and carer wellbeing. The survey will be developed by the research team, many of whom are experts in intellectual disability within their own jurisdictions. Using back-translation our team will translate the survey for distribution in 18 countries worldwide for international comparison. The survey team have extensive personal and professional networks and will promote the survey widely on social media with the support of local disability and advocacy agencies. Statistical descriptive and comparative analyses will be conducted. Ethical approval has been obtained for this study from University College Dublin's Human Research Ethics Committee (HS-20-28-Linehan). Dissemination: Study findings will be prepared in a number of formats in order to meet the needs of different audiences. Outputs will include academic papers, lessons learned paper, practice guidelines, reports, infographics and video content. These outputs will be directed to families, frontline and management delivering disability services, national-level policy makers, healthcare quality and delivery authorities, national pandemic organisations and international bodies.

COVID-19 IDD: A global survey exploring family members' and paid staff's perceptions of the impact of COVID-19 on individuals with intellectual and developmental disabilities and their caregivers

Background: This protocol outlines research to explore family members' and paid staff's perceptions of the impact of COVID-19 on individuals with intellectual and developmental disabilities and their caregivers. Evidence suggests that people with intellectual and developmental disabilities experience disparities in healthcare access and utilisation. This disparity was evident early in the pandemic when discussions arose regarding the potential exclusion of this population to critical care. Methods: An anonymous online survey will be conducted with caregivers, both family members and paid staff, to explore their perceptions of the impact of COVID-19 in terms of demographics, living arrangements, access to services, social distancing, and carer wellbeing. The survey will be developed by the research team, many of whom are experts in intellectual disability within their own jurisdictions. Using back-translation our team will translate the survey for distribution in 18 countries worldwide for international comparison. The survey team have extensive personal and professional networks and will promote the survey widely on social media with the support of local disability and advocacy agencies. Statistical descriptive and comparative analyses will be conducted. Ethical approval has been obtained for this study from University College Dublin's Human Research Ethics Committee (HS-20-28-Linehan). Dissemination: Study findings will be prepared in a number of formats in order to meet the needs of different audiences. Outputs will include academic papers, lessons learned paper, practice guidelines, reports, infographics and video content. These outputs will be directed to families, frontline and management delivering disability services, national-level policy makers, healthcare quality and delivery authorities, national pandemic organisations and international bodies.

Analyzing essays about treating adults with special health care needs and intellectual and developmental disabilities

OBJECTIVE

Analyze reflection essays written by one graduating class of students after an initial experience in a clinic for adults with special health care needs (SHCN) and intellectual and developmental disabilities, to draw insights from the patterns of observations expressed.

METHODS

Essays were written by students from the University of Colorado School of Dental Medicine during the 2016-2017 academic year after completing a 1-day clinical experience treating this patient population. Readers identified 18 primary themes (PTs) previously identified in essays written during 2012-2013.

RESULTS

The PT Complex communicating through third party was identified in 79.4% of essays. Least common were Frustrated patient could not understand (1.9%) and Frustrated patient could not talk (1.9%). Nine PTs were grouped to represent 3 component themes (CTs): CT1 Communication challenges, CT2 Behavioral challenge, and CT3 Altruistic responses. This grouping showed moderate internal reliability. A fourth, CT4 Emotional challenges, was rejected due to low internal reliability. CT1 was most frequently identified, followed by CT3 then CT2. Three PTs were chosen as indicative of desirable outcomes and were labeled outcome themes (OTs): OT1 Willing to see patients with SHCNs after graduation, OT2 Would like more Special Care Clinic (SCC) experiences in the future, and OT3 Looking forward to next SCC experience. Associations between CTs and OTs were not statistically significant, but provided useful insights.

CONCLUSION

Reflection essays indicate discussion of strategies to manage behavioral challenges and encouragement of altruistic feelings are both vital in orientation sessions. These topics may be critical to positive student perceptions of the experience.

A case-study of policy change in residential service provision for adult persons with intellectual disability in Ireland

In Europe, many people with intellectual disabilities continue to live in congregated settings. In 2012, Ireland formally introduced a resettlement policy with people moving to live in more personalised arrangements. This longitudinal country case-study aimed to monitor the implementation of this policy and the intra-country variations that arose using the records maintained in the National Intellectual Disability Database. Details of over 4,000 people living in congregated settings were examined in 2007 and again in 2012 and 2017. In addition, people who moved from such settings from 2007 onwards were tracked and the number of new admissions to them was estimated over the 10-year period. Overall there was nearly a 30% drop in the numbers of people in congregated settings but the reductions varied markedly across the country and by 2017 the disparity was greater than in 2007. Also by 2017 persons aged over 55 years were eight times more likely to be accommodated in congregated settings. The case-study illustrates the value of a longitudinal dataset for monitoring policy implementation across a diversity of provider organisations and administrative areas.

Factors Influencing Low Prevalence of Neurodevelopmental Disabilities Among US Hispanic/Latino Children

OBJECTIVES

Hispanic/Latino (H/L) children have lower prevalence of neurodevelopmental disabilities (NDD) than other groups. The explanations for this are complex, but may be related to nativity, language barriers, and lack of access to and utilization of healthcare. Previous research focused on how these factors affect children with NDD, but little research has jointly examined whether these factors predict NDD. This study examines whether social and environmental factors explain low prevalence of NDD in this population.

METHODS

This study uses nationally representative Integrated Public Use Microdata Series National Health Interview Survey data (N = 200,622) and multivariate logistic regression analysis to compare NDD prevalence in white and H/L children (average age of 10.2), and examines whether nativity, healthcare access, healthcare utilization, and language barriers explain this disability disparity.

RESULTS

Findings reveal that the H/L NDD disparity is not explained by differences in access to or utilization of healthcare, or as a result of language differences that may create barriers to NDD diagnosis. While H/L children whose sampled adult was born in the USA have lower rates of NDD than whites, H/Ls whose sampled adult were not born in the USA have even lower probability of NDD than H/Ls who were born in the USA.

CONCLUSIONS

These findings may be a result of cultural differences in knowledge or understanding of what constitutes a disability or the result of differential treatment within the healthcare system among H/Ls. The findings underscore the importance of accessible and culturally appropriate health and clinical care interventions among H/L communities.

The prevalence of intellectual disability: A comparison of national census and register records

BACKGROUND

International prevalence rates for intellectual disability vary widely with estimates often based on samples. In Ireland people with an intellectual disability are identified in the national census. Moreover, a national register of people receiving or requiring intellectual disability services is maintained and updated annually.

AIMS

The prevalence rates from the census were contrasted with those from the register along with variations in prevalence across the 26 counties of Ireland.

METHODS

2011 and 2016 Census of Population prevalence per 1000 for children (aged 5-19 years) and adults (20 years and over) stratified by the 26 countries were contrasted with similar prevalence in the national register. Publically available data from the 2011 census in Northern Ireland and Scotland were obtained.

RESULTS

The Irish census identified nearly twice as many children and adults than were on the national register. Prevalence rates also varied across the 26 counties; more so on the register than the census. The Irish census had lower prevalence rates than Northern Ireland but higher than Scotland.

CONCLUSIONS

Determining the prevalence of intellectual disability is challenging due to variations in terminology. A national register has advantages over reliance on census data for service planning.