Abstract
Introduction
Patients with trisomy 21 (Down syndrome [DS]) are at higher risk for developing certain diseases such as epilepsy or hypothyroidism compared to the normative population (Baksh et al., 2023). Alzheimer’s disease (AD) is particularly noteworthy here due to the significant lifetime risk of approximately 90% (Levin et al., 2023). While the prevalence of AD in the general population is estimated to be 3% for people older than 40 years and 6% for people over 60 years, the corresponding prevalence for PwDS is estimated to be 22% and 56%, respectively (Janicki and Dalton, 2000). Up to 80% of people with DS are expected to develop dementia by the age of 65, marking the highest risk of dementia in any population group (Coppus & Telbis-Kankainen, 2016).
For several reasons, the diagnosis and treatment of dementia in PwDS must be designed differently than in the normative population (Loosli, 2021). Given the intellectual impairment of PwDS there is a need for different screening tools and other assessment strategies than in conventional dementia diagnosis. The diagnosis of AD in PwDS is challenging due to the heterogeneous phenotype, the wide range of cognitive baseline levels among PwDS, and the lack of standardized testing procedures. Reliable information on baseline levels and symptom progression can usually only be obtained from an external medical history (Nübling, 2022). The occurrence of misdiagnosis or underdiagnosis is therefore a potential risk.
Therapeutic approaches such as occupational therapy, movement therapy, and speech therapy should be adapted to the specific needs and circumstances of PwDS. To enable a good prognosis and early symptomatic and socio-medical therapy planning, a precise diagnosis of AD is central (Hüer, 2024). Accurate and early diagnosis allows for appropriate care adaptations, and as pharmaceutical interventions become more effective, especially in the early stages of AD, could delay the progression of the disease in the future (Singh et al., 2024).
The life expectancy and the associated risk of developing dementia in PwDS increases significantly (Iulita et al., 2022). Therefore, appropriate healthcare provision for this vulnerable group should be developed. This is also considered in the “Convention on the Rights of Persons with Disabilities” of the United Nations by the demand of free access to medical treatment and research for people with impairments (United Nations, 2006). However, medical practice suggests that knowledge of the significantly increased risk of disease is not adequately reflected in healthcare structures. In research, the resulting problems for care receive little attention.
Given these challenges, the research project “DS-Demenz” - “(Access to) diagnosis and treatment of dementia in people with Down syndrome” (funding code 01VSF21030) - funded by the German Innovation Committee of the German Federal Joint Committee (Gemeinsamer Bundesausschuss) aims to develop health policy recommendations for action to improve the medical care for PwDS and dementia. Therefore, a mixed-methods-approach is used to first, identify deficits and weaknesses in current medical care and second, to develop options for improvement of medical care based on this. This scoping review served as a starting point aiming at identifying and classifying problems along the patient journey of PwDS and dementia, in order to answer the research question “Which care deficits, barriers and obstacles can be identified in the care of PwDS and dementia?”.
Methods
Overview
A scoping review was conducted to identify deficits and barriers in medical care for PwDS and dementia. The review was based on the five mandatory phases for scoping reviews proposed by Arksey and O'Malley (Arksey and O’Malley, 2005) and further developed by (Levac et al., 2010). The manuscript was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). A study protocol has not been previously published.
Search strategy
The medical databases EMBASE, MEDLINE via PubMed and PsycINFO were systematically searched for eligible articles which were published between January 1st 2013 and September 27th 2022. The search strategies were mainly developed by the Institute for Healthcare Management and Research (University Duisburg-Essen). The project partners provided support, in particular through medical expert input.
The search string was developed using the PCC scheme (Patient/Population = PwDS and AD, Concept = medical care, Context = medical care environment). Relevant search terms were identified based on the search scheme and linked using “AND” as well as “OR” connectors. Search terms were limited by their occurrence in the abstract, title or key words. If eligible key words (MeSH, Emtree) were present, they were included in the search string. The final search strings for each database can be found in Appendix 1.
Identified articles were saved from the data bases into the literature management system EndNote (version 20; Clarivate). Reference lists of included articles and web sites of relevant stakeholders were searched to identify additional evidence respectively further deficits and barriers. In case of available search fields, these were used to search for key words. Otherwise, relevant sub-pages on the topic were searched.
Inclusion criteria
Articles were searched, that describe deficits and barriers in medical care of PwDS or people with comparable intellectual impairments and dementia. Articles were considered for inclusion if they were peer-reviewed (except web sites of relevant stakeholders) and published between January 1st 2013 and September 27th 2022 in English or German. As the aim of our scoping review was to map existing research and provide a broad overview on existing literature, as a starting point for our research project, articles were included irrespective of their study design and method. More detailed inclusion and exclusion criteria can be found in Textbox 1 and Textbox 2.
• I1: Down syndrome or a comparable impairment and (Alzheimer’s) dementia • I2: Description of deficits and barriers, in the context of: ○ (Access to) diagnostics, or ○ (Access to) treatment
• E1: Medical-scientific focus on: ○ Diagnostic instruments, or ○ therapeutic methods, or • E2: preclinical research, or • E3: Individual therapeutic measures • E4: Research protocols, conference abstracts, letters to the editor, or • E5: Publications before 2013, or • E6: Other languages than English or German, or • E7 Full-text not available
Article selection and data extraction
After downloading the citations and inserting them into EndNote, duplicates were first removed by software and then manually. The review and selection of articles was carried out in a two-stage process. First, two reviewers (GDG & PR) independently assessed titles and abstracts for potential suitability. In a second step, the articles under consideration were checked against the inclusion and exclusion criteria in the full-text review. Cases of discrepancies were resolved by including two additional authors (TH, AW).
Relevant characteristics and contents of included articles were marked and extracted using the software MAXQDA (VERBI Software GmbH). Extraction of metadata (e.g., author, year, study design) was performed using a previously determined table (cf. Appendix 2). The identified and extracted text passages including deficits and barriers in the medical care of PwDS and dementia, were summarized to concise short statements and initially captured unsystematized in Excel (Microsoft).
Synthesis of results
The systematization and grouping of the results were subsequently carried out on the basis of the summarized short statements in a workshop by the researchers of the Institute for Healthcare Management and Research and EsFoMed (GDG, PR, MW, AW, TH). In a first step, the short statements were read aloud to get a feeling for the contents. At the same time, a vague sorting was carried out. This revealed two dimensions according to which the statements could be sorted. These were (1) medical areas (diagnostics, therapy, research, and overarching issues) and (2) concerned stakeholders (patients, formal and informal caregivers, as well as medical and other service providers). Using these dimensions, a two-dimensional matrix was developed which served for final evaluation and synthesis of results. One exception was the subject area of (medical) research. As research usually affects more than one specific group of people, the deficits and problems identified in this area were not broken down into stakeholder groups.
Results
Selection of evidence sources
The systematic search yielded 2,738 articles after removing duplicates (cf. Figure 1). Thereof, 42 full texts were assessed against the inclusion and exclusion criteria after the initial title and abstract screening. Finally, 24 articles, which were assessed as eligible to provide information on the research question, remained after the screening process. These were supplemented with two articles from web sites of relevant institutions. Thus, finally 26 articles were considered (cf. Appendix 2). The reference list search did not return any further hits that contained problems that were not already addressed in the included articles. Flow chart to illustrate the selection of evidence sources.
Included studies
Fifteen of the 26 finally included articles are primary studies, 4 are reviews, 4 are consensus statements, two are guidelines, and there is also a project report. The articles stem mostly from the USA (n = 5), the UK (n = 5) and Ireland (n = 3). Five studies are transnational. Nine of the 15 primary studies have a qualitative design, four studies have a quantitative and two have a mixed-methods design (qualitative and quantitative). All included references and their respective characteristics are summarized in Appendix 2.
Synthesis of results
Overview
The results are presented in accordance with the problem systematization developed during the workshop. The problem areas of diagnosis, therapy, research as well as overarching issues served as overarching chapters. Within these chapters, the respective results were structured according to the stakeholders involved (patients, formal and informal caregivers, as well as medical and other service providers). Regarding the problem areas, in some cases, deficits and barriers were identified that affected both diagnosis and treatment. Therefore, a corresponding section (Diagnosis / Therapy) was added in the results (cf. Figure 2). Regarding the affected stakeholders, some problems could not be specifically assigned and were therefore grouped in a further category (Cooperation and interface). Appendix 3 shows which areas were addressed in which of the included articles. Areas in which deficits and barriers in the medical care of PwDS and dementia were identified.
Diagnosis
Problems in the context of diagnosis were described in 18 articles (cf. Appendix 3). Problems concerned patients, caregivers, medical and other service providers, as well as cooperation and interface (cf. Appendix 4).
Patients
On the one hand, people with learning difficulties, tend to downplay or deny their difficulties (Kuhn, 2014). On the other hand, according to caregivers, poor communication skills of this patient group are described as a barrier to recognizing mental health problems in the first place (Herron and Priest, 2013; Wolff and Müller, 2014).
Caregivers
For both, formal and informal caregivers, it is difficult to identify symptoms, since dementia symptoms can be subtle. Cognitive impairments together with normal aging effects might partially mask the symptoms (Bishop et al., 2015; Heller et al., 2018).
Formal Caregivers
Diagnosis of dementia in PwDS also affects their formal caregivers. Problems arise from inadequate medical or nursing training for caregivers regarding dementia in people with intellectual disabilities, insufficient information, and lack of awareness of the topic. These reasons not only lead to difficulties in recognizing early or middle stages of dementia, but also in detecting (symptom) changes over the natural progression of the disease. (Axmon et al., 2016; Bishop et al., 2015; Cleary and Doody, 2017a, 2017b; Dekker et al., 2021; Heller et al., 2018; Herron and Priest, 2013; Ryan et al., 2018)
Some formal caregivers have misconceptions about the progression of AD in PwDS (Ilacqua et al., 2020) and consider behavioral changes in individuals in isolation and attribute them to different underlying causes (Herron and Priest, 2013). Such presumed causes include abuse, an underlying physical health problem, or depression (Herron and Priest, 2013). If PwDS and dementia behave more appropriately and cooperate better with caregivers, this is often perceived as an improvement in well-being rather than the onset of dementia (Cleary and Doody, 2017a). Often, formal caregivers focus on conspicuous and noticeable problems and not on subtle changes in mood, behavior and attitudes toward others (Herron and Priest, 2013). Assessing changes in behavior requires a good knowledge of the person being cared for. However, this can be complicated by resident moves and staff changes in facilities (Wolff and Müller, 2014).
Finally, there is criticism of the diagnostic tools used in facilities for the disabled. Only a few neuropsychological tests or screening procedures are used (Wolff and Müller, 2014).
Informal Caregivers
Informal caregivers also lack knowledge and information about recognizing dementia symptoms. Thus, the inability to differentiate symptoms of dementia from those of DS or intellectual impairment may be a barrier to diagnosis (Bishop et al., 2015; Dekker et al., 2021; Heller et al., 2018; Ilacqua et al., 2020; Raj et al., 2020). A lack of awareness is likely, since one study found that only 40% of caring relatives had ever discussed the risk of developing AD in PwDS with a medical specialist (Ilacqua et al., 2020).
Furthermore, although not specified in detail in the literature, the difficulty to accept the disease may be a barrier to diagnosis (Raj et al., 2020). In part, the views and expectations of caregivers may have a major impact on acceptance of screening (Rowe, 2016). Some relatives may not agree that the person they care for receives worrying news (Ryan et al., 2018).
Medical and other service providers
The diagnosis of dementia in PwDS is particularly challenging for medical staff. On the one hand, there is a lack of experience (Holst et al., 2018); on the other hand, there is a risk that awareness of the association between DS and dementia might lead to premature diagnoses (National Down Syndrome Society, 2018).
Another problem is the lack of methods developed to measure cognitive decline in people with intellectual impairments (Holst et al., 2018). In some cases, screening and diagnostic instruments are not suitable for people with intellectual impairments (Bishop et al., 2015; Heller et al., 2018; Santos et al., 2018); in other cases, they have been developed for the target group, but are not used in practice (Heller et al., 2018). If dementia is suspected, the initial assessments must be compared with longitudinal assessments. Since there are periods of up to one year between assessments, this leads to uncertainty and delays in the further planning after the diagnosis (Herron et al., 2020).
Cooperation and interface
Problems concerning cooperation and interface in medical care can be divided into structural problems on the one hand and indication-related problems on the other. Structural problems include a lack of specialized clinicians (Bishop et al., 2015), especially in non-urban areas (Heller et al., 2018), and the lack of guidelines from authorities encouraging the reporting of suspected cognitive decline (Bishop et al., 2015).
Indication related problems can be observed especially in the case of late diagnosis (Wolff and Müller, 2014) and diagnostic overshadowing (Axmon et al., 2016; Heller et al., 2018; Herron and Priest, 2013; Herron et al., 2020; Ilacqua et al., 2020; Rowe, 2016; Santos et al., 2018; Wolff and Müller, 2014). In this context, this means that symptoms caused by dementia are incorrectly attributed to intellectual impairments or causes other than dementia and the disease is therefore not recognized. Conversely, behavioural changes can have other causes and might be misinterpreted as dementia (Bishop et al., 2015). Moreover, an international summit consensus statement highlighted that promoting early diagnosis would be a challenge (Watchman et al., 2017).
Therapy
Deficits and challenges were also found in the context of therapy. These were thematized in eight articles (cf. Appendix 3) and concerned patients, formal caregivers, medical and other service providers as well as cooperation and interface (cf. Appendix 4).
Patient
People with Down syndrome (PwDS) face special challenges concerning their access to therapy. This is shown by a survey of people with intellectual disabilities and relatives investigating the use of services such as specialist consultations and resources such as medication or physical aids. Participants described the burden of paperwork, the difficulty of coordinating meetings, and long waiting times for approvals from government agencies when they needed financial support especially for services, medical devices, and medications for people with disabilities (Baumbusch et al., 2019).
Furthermore, a study by Axmon et al. found that people with intellectual impairment and dementia were less likely to receive planned healthcare than people with dementia in the general population. However, the level of unplanned healthcare use was higher. This may indicate that the current system is inadequate to meet the challenges of increased life expectancy for people with intellectual impairment and dementia. (Axmon et al., 2016)
Finally, it was found that people with intellectual impairment and dementia were found to be more likely to be prescribed antipsychotics than people with either intellectual impairment or dementia alone. Considering the communication difficulties, adverse effects of inappropriate medications should be considered. (Axmon et al., 2017).
Formal Caregivers
Formal caregivers need a lot of knowledge about multimorbidity and especially about polypharmacy. They have to be able to provide support in dealing with such problems. (Holst et al., 2018)
Medical and other service providers
Service providers affected in the context of therapy are, in particular, medical service providers, physio and occupational therapists. Medical service providers lack training and knowledge regarding the therapy of people with intellectual impairment and dementia (Rowe, 2016). Clinics specializing in DS provide different services, are staffed differently, and vary in the age of patients admitted with DS (Ilacqua et al., 2020). Concerns have also been expressed that the health of people with intellectual impairments and dementia could deteriorate because of confusion in unfamiliar places, infections or inadequate nourishment (Chapman et al., 2018). A special concern was seen regarding do-not-resuscitate orders which are often made without the necessary caution and consultation with patients or their relatives, which can lead to considerable emotional stress (Chapman et al., 2018).
In terms of therapists, a limited availability of physiotherapy (Cleary and Doody, 2017a) and occupational therapy (Raj et al., 2020) is described. The latter was highlighted in a study where only 56% of surveyed occupational therapists stated providing services (such as home safety education and training) to informal caregivers of PwDS and dementia (Raj et al., 2020). Occupational therapists identified several issues, including a limited number of colleagues, long waiting lists, a lack of referrals from stakeholders, rare collaboration with informal carers, and geographical restrictions to service provision (Raj et al., 2020).
In occupational therapy, besides the shortage of therapists, a lack of financial resources was identified as a reason for the insufficient provision of services. In addition, the access to specific knowledge about working with people with intellectual impairments is limited and the time available to develop skills and to acquire knowledge is scarce (Raj et al., 2020).
An inadequate relationship with the person with intellectual impairment and his or her caregiver was also thematized. It could be difficult to focus on the best interests of the person. More frequently, the role of caregivers in the lives of persons with intellectual impairment was not recognized, and there was a lack of awareness and understanding for the concerns of caregivers (such as grief over the loss of skills) (Raj et al., 2020)
Cooperation and Interface
Deficits affecting multiple stakeholders included a lack of support for formal caregivers in agencies as concerns carrying out all post-diagnostic prescribed activities (Bishop et al., 2015). Occupational therapists expressed that services were fragmented and not recipient-centered (Raj et al., 2020). This was evidenced by a limited understanding of the role of occupational therapists in interdisciplinary teams and a lack of coordinated team approaches (Raj et al., 2020).
Diagnosis/Therapy
Problems that affected both diagnosis and therapy were described in 12 articles (cf. Appendix 3). They were found for patients, caregivers, medical and other service providers and cooperation and interface (cf. Appendix 4).
Patient
Problems on the patient side exist firstly in psychological challenges associated with diagnosis and treatment (Baumbusch et al., 2019; Rowe, 2016); secondly, the inability of patients to recognize their need for support, leading potentially to self-harm (Ryan et al., 2018); and thirdly, the difficulty of communicating deterioration, which makes them highly dependent (Dekker et al., 2021).
Psychological challenges related to diagnosis exist due to the overwhelming complexity of treatment plans and the health care system, as well as the anxiety of waiting in unfamiliar places for appointments (Baumbusch et al., 2019). Furthermore, screening information can have a major impact on the mental health and the well-being of individuals, since people with intellectual impairments are particularly susceptible to depression and states of anxiety (Rowe, 2016).
Caregivers
It is difficult to find appropriate, useful services that serve to rule out diseases with symptoms similar to chronic dementia that mask or exacerbate the disease. Therefore, patients are dependent on family, friends or (caring) staff. These can act as advocates (Bishop et al., 2015) but they can also act as gate-keepers in the context of preventive medical check-ups, services and support and thereby prevent the use of services (Chapman et al., 2018).
In order to actually make use of appointments, it may be necessary to have support persons available. This makes scheduling more complicated. Lack of flexibility and the feeling that proposed appointments must be accepted or providers will not be available at all lead to resentment among caregivers. (Baumbusch et al., 2019)
Informal Caregivers
Less than 50% of caring relatives ask health care professionals for information about AD. When doing so, family caregivers are, on average, only moderately satisfied with communication (Ilacqua et al., 2020). This could be due to a lack of knowledge and experience on the part of both persons with intellectual impairment and family caregivers in interacting with corresponding health care providers (Baumbusch et al., 2019). Some informal caregivers use information from scientific publications or the internet (Ilacqua et al., 2020), although scientific literature is difficult to understand even for well-educated people and might easily be misunderstood. The use of literature could be explained by a feeling of caregivers that they cannot get the information, they need, elsewhere (Ilacqua et al., 2020).
Medical and other service providers
Poor availability of health care providers with training or experience in the treatment of adults with intellectual impairment is a common problem (Axmon et al., 2016; Baumbusch et al., 2019; Ilacqua et al., 2020; Santos et al., 2018). In addition, health services are poorly prepared to fulfil the special needs of individuals as they age in their communities (Baumbusch et al., 2019).
Physicians lack knowledge on DS in people with intellectual disabilities (Baumbusch et al., 2019; Bishop et al., 2015; Holst et al., 2018). This is also reflected in communication difficulties with individuals. Physicians might not communicate in an appropriate speed and manner. Thereby, information might be misunderstood (Rowe, 2016).
Health care providers can have a poor attitude toward people with intellectual impairment (Holst et al., 2018). Due to prejudices health care providers question the credibility of self-reported information of patients (Bishop et al., 2015). To obtain reliable information, clinicians are sometimes dependent on close relatives and caregivers of people with intellectual impairments. However, this information does not necessarily reflect the opinions and expectations of the individual (Rowe, 2016).
Other problems include the use of medical approaches that are common in the general population but would need to be adapted for the target group (Dodd, 2015). Challenges also exist regarding the role and involvement of other health care providers (such as psychiatrists and general practitioners) after diagnosis (Chapman et al., 2018).
Cooperation and Interface
Receiving health care that could benefit PwDS is resource intensive in terms of time and money, which can be seen as a barrier to access (Baumbusch et al., 2019). In addition, problems with access exist due to dependence on third parties (Baumbusch et al., 2019; Bishop et al., 2015; Chapman et al., 2018) and due to an insufficient availability of health care providers (Axmon et al., 2016; Baumbusch et al., 2019; Bishop et al., 2015; Ilacqua et al., 2020; Santos et al., 2018).
Research
Deficits in research fall into two categories. First, there is an insufficient involvement of stakeholders such as caregivers in research (Heller et al., 2018). Second, ethical restrictions regarding the inclusion of people with intellectual impairments can be challenging for researchers (Watchman et al., 2019). Dodd et al. (2018) especially pronounced limited research evidence for pharmacological or non-pharmacological interventions for people with intellectual disability and dementia.
Parents of people with intellectual impairments have specific knowledge and relevant concerns associated with end-of-life care, abuse and neglect, housing support, health deterioration, financial support and use of assistive technology. Nevertheless, they are insufficiently included in general studies to dementia care (Heller et al., 2018).
Watchman et al. (2019) claim that there might also be barriers posed by research ethics (or institutional) board reviews – in particular, where ethics boards might not recognize the value and ability of adults with intellectual impairments to be informants in studies or by imposing “over-protective conditions” in the conduct of research which would impede the involvement of adults with intellectual disability in studies (Watchman et al., 2019).
Overarching
Overarching problems were found in 16 articles (cf. Appendix 3). They concerned patients, caregivers, medical and other service providers as well as cooperation and interface (cf. Appendix 4).
Patient
Overarching problems concerning the patients were described in three key areas: firstly, the self-determination of individuals living with the condition (Ilacqua et al., 2020; Santos et al., 2018; Watchman et al., 2019), secondly, ethical and legal questions surrounding examinations that they may neither fully understand nor want (Holst et al., 2018), and thirdly, a lack of financial resources, as many individuals often rely on state pensions (Baumbusch et al., 2019).
Few is known about the perspectives of adults with intellectual disabilities. This could be due to fewer possibilities and abilities to speak for themselves (Santos et al., 2018). The meanings and preferences of individuals with intellectual disabilities and authorized representatives (e.g., family members who may speak for the individual) may differ, and the voices of individuals may be lost (Watchman et al., 2019). Often, PWDS are not consulted about dementia by their caregivers, because it is assumed that they would not understand or would be too young to think about the consequences of dementia (Ilacqua et al., 2020).
Caregivers
Formal and informal caregivers lacked information about dementia in people with severe/profound intellectual impairments (Dekker et al., 2021).
Formal Caregivers
In the literature two overarching deficits are described for formal caregivers. First, the training and knowledge of informal caregivers is insufficient regarding intellectual impairments and dementia. Second, they often fail to explain the behavioral changes in individuals, or they do so in the wrong way.
Only few formal caregivers were educated regarding intellectual impairment (Chapman et al., 2018; Holst et al., 2018), in dementia (Dekker et al., 2021; Herron and Priest, 2013; Holst et al., 2018), or both (Cleary and Doody, 2017a; Iacono et al., 2014). In general, not many caregivers have received special training in mental health and many were insecure as to how they could apply their knowledge. Most gave wrong assessments about the meaning of some symptoms of mental health (Herron and Priest, 2013). Even if formal caregivers are alert to behavioral changes and mistreatment, their knowledge of dementia is low (Herron and Priest, 2013).
Especially staff in facilities for older individuals lacked knowledge about coping with patients with intellectual impairments and the recognition of potential health problems (Chapman et al., 2018). Similarly, dementia nurses are not trained for coping with people with intellectual impairment and therefore have limited knowledge (Holst et al., 2018). A special issue in the education was an inconsistent use of language and an insufficient understanding of the difference between the types of dementia (Santos et al., 2018).
Formal caregivers had difficulty attributing changes in individuals to either AD or other factors, such as personality or education. Even if they were educated about AD, they rather tended to rely on their knowledge about intellectual impairment and challenging behavior than on their knowledge of dementia. The specific knowledge of intellectual impairment guided the applied strategy. (Iacono et al., 2014)
Informal Caregivers
Informal caregivers face two overarching challenges. First, the organization of medical care is very difficult and complex. Second, they might be unable to recognize dementia in their relatives and have difficulties accepting the disease (Raj et al., 2020).
Informal caregivers are unfamiliar with available information and hesitate to seek assistance for the understanding of the disease (Bishop et al., 2015). When they seek for assistance, caring relatives face many challenges and have only few supporting structures, they can fall back on. Therefore, they are dependent on mutual support and the support of family members (Herron et al., 2020). Organization of a referral or the implementation of care proposals might be challenging, if the caring person does not have contact to a person able to guide (Bishop et al., 2015).
Informal caregivers can suffer from stress, depression, poor health and financial hardship (Heller et al., 2018; Raj et al., 2020) and lack of a support network (Raj et al., 2020). Regularly, reinforcing the problems, caring relatives are older adults with own age-related impairments; many are women in moderate age (Santos et al., 2018).
Medical and other service providers
An overarching problem in specialists is that they often do not know the individuals and rely on things they either see or are told by others. But this does not necessarily reflect the wishes and the need for support of persons with intellectual disabilities (Watchman et al., 2019).
Cooperation and Interface
Deficits in access, inadequate services and the question about the right decision-maker were challenges in cooperation and interface. The most significant overarching problem with access is the access to information or rather its unavailability (Heller et al., 2018; Watchman et al., 2019). Those information materials which are available, are mostly in English and do not reflect differences in language and culture (Watchman et al., 2019). Even if studies showed usefulness of available programs and services, these consider only either care for older adults or care for people with intellectual impairments, but not both (Heller et al., 2018).
Further overarching problems were seen in the availability of specialized health care services (Baumbusch et al., 2019), in an insufficient concentration on challenges experienced by older individuals (Watchman et al., 2017) and in lack of knowledge in care facilities about methods of dementia screening and support in people with limited intellect (Holst et al., 2018).
There is a mismatch between the needs of Alzheimer organizations to provide more services and the lack of awareness of government agencies and ministries about the needs of people with intellectual impairments or their families. In addition, there is a lack of financial support, in particular, from governments and a challenge in coordinating services at the local level. (Watchman et al., 2017)
A consequence of inadequate services is a reduction of their use. If provided services do not fulfill the needs of caregivers and contact with agencies does not lead to useful information, the probability that caregivers will use the available services is lower (Fleming and Litzelman, 2021).
Further challenges arise due to increasing cognitive impairment (e.g., ability of informed decision-making) (Watchman et al., 2017). There are cases where support staff is the main caring person over longer periods if there is no family nearby. This can lead to tensions concerning the question “who is the primary decision maker?”. This could potentially be the parents or caregiver, the person with intellectual impairment or another person having the decision-making authority (Watchman et al., 2019).
Discussion
Principal findings
In this scoping review multiple deficits and barriers in the medical care of PwDS and Dementia were identified. These concerned principally the diagnosis, the therapy, and research. Some problems were overarching. Issues affected the patients themselves, formal and informal caregivers, medical and other service providers or the cooperation and interface between different stakeholders.
Three major topics identified in this review should be highlighted: (1) lack of available services, (2) lack of knowledge, and (3) special characteristics of PwDS.
First, a lack of available services was described, particularly in terms of difficulties in accessing medical care. This contradicts the World Health Organization (WHO) global action plan on public health responses to dementia, which clearly emphasizes the equity aspect of including all vulnerable groups, such as people with disabilities (World Health Organization, 2017). The European Commission also demands for access to quality services, such as health care for every citizen, especially for those who are in vulnerable situations, for example due to their health status (European Commission n.d.). In countries such as Australia and the United Kingdom people with intellectual impairments receive comprehensive annual health checks to improve screening, identification and management of treatable conditions (Woodward et al., 2020).
In the case of PwDS gaining access to screening appointments, a further problem identified was the lack of appropriate screening instruments. A recommendation regarding this problem is provided in the “Evidence-based clinical practice guideline for adults with Down syndrome” by Tsou et al. (Tsou et al., 2020). Medical professionals should assess the patients themselves and their primary caregivers annually, beginning at the age 40 years, for changes from baseline function in the following dimensions: (1) cognition, memory, and executive function, (2) behavior and personality, (3) communication, (4) adaptive functioning, (5) ambulation and motor skills, and (6) general decline in established skills.
Second, the literature describes a severe lack of knowledge and skills among medical and caregivers in the context of PwDS and dementia. This can lead to under-diagnosis of dementia due to diagnostic overshadowing on the one hand, and to misdiagnosis due to an over-focus on the known association between DS and AD on the other.
PwDS benefit from the care of specialists who are familiar with the corresponding behavior of this patient group, which might otherwise be mistakenly interpreted as pathological. Therefore, referral to such specialists is recommended for mental disorders in PwDS (Tsou et al., 2020).
Low availability of appropriate information for informal caregivers was described as a further salient problem in this area. Although there are a number of organizations developing informational materials for dementia in PwDS (e.g., Global Down Syndrome foundation n.d., Down’s Syndrome Association, 2018; National Down Syndrome Society, 2018), these do not appear to be sufficient for individuals or their caregivers or do not fully meet their needs.
The literature describes the unavailability of guidelines. Even if there is a general guideline for the medical care of adults with DS (Tsou et al., 2020), such guidelines are often lacking at the national level. In Germany, for example, there is no relevant guideline on dementia in PwDS. The 2016 S3 dementia guideline mentions DS only once as a diagnostic criterion for atypical AD; the new edition does not mention this specific group of people at all (Deutsche Gesellschaft für Psychiatrie und Psychotherapie, Nervenheilkunde e. V. et al., 2023).
Finally, the special characteristics of PwDS present a challenge. Symptoms can be subtle and behavioral changes are often attributed to the intellectual impairment of PwDS. PwDS often have limited communication skills, which reinforces the problem. These findings are in line with Matthews et al. who found that current health issues negatively affect communication skills in PwDS (Matthews et al., 2018).
However, communication problems are not only caused by the difficulty of patients in expressing themselves. An analysis of a 2008 US physician survey found that only 76% of physicians surveyed felt comfortable providing medical care to PwDS and 9.8% felt uncomfortable (Pace et al., 2011). Although if the results are older, they underscore the issues identified in this scoping review.
A final issue that should be mentioned is dependency on caregivers and the lack of self-determination. As more self-determination of PwDS leads to better skills in many areas such as memory, motor and language skills (Landuran et al., 2022), it is important to ensure this as much as possible.
Outlook on solutions
As almost 100% of PwDS have AD neuropathology by age 40 years (“Strengthening connections between Down syndrome and AD”, 2013) and the life expectancy of people with Down syndrome increased significantly (Bittles and Glasson, 2004; Bittles et al., 2007) the need for adequate medical care is becoming even more important than before to protect this vulnerable group.
Although there are many deficits and barriers in the medical care of PwDS or similar intellectual impairments, there are also many suggestions in the literature on how to improve medical care for this group. A key overarching solution is to educate and train caregivers, medical professionals, and family members (Bishop et al., 2015; Heller et al., 2018; Herron et al., 2020; Rowe 2016; Santos et al., 2018).
In the context of diagnosis, caregiver awareness of dementia-associated symptoms (Bishop et al., 2015; Heller et al., 2018), early (Heller et al., 2018) and regular dementia screening and follow-up after age 40 (Santos et al., 2018), as well as needs and self-determination of individuals (Dodd et al., 2018; Rowe, 2016) should be considered.
In terms of therapy, possible solutions could include increasing the capacity of the workforce (Watchman et al., 2017), addressing communication difficulties in older patients (Axmon et al., 2017), reducing stress and providing resources to avoid and minimize the negative aspects of caregiving (Santos et al., 2018), and providing services through an interdisciplinary team using a patient-centered care model (Raj et al., 2020).
Research should include people with intellectual impairments and their caregivers (Chapman et al., 2018; Heller et al., 2018, Watchman et al., 2019) and should especially focus on access to health care in this vulnerable group (Axmon et al., 2016). In this context, however, it also must be taken into account that ethical and legal regulations in most countries do not allow the inclusion of people who are unable to give informed consent in research projects, or only if very strict requirements are met. These regulations serve to protect vulnerable people who are unable to consent and must therefore not be weakened. On the other hand, people with Down syndrome who are in an early stage of dementia should not be denied their ability to consent from the outset. Hence, before including a person with Down syndrome in a research project, it should always be carefully checked whether they have the capacity to consent or not.
This scoping review summarizes the evidence on deficits and barriers related to medical care for PwDS or similar intellectual impairments. The discussion provided some insights into possible further research areas that should be investigated. As part of the DS-Demenz research project, the aim is to improve the medical care for PwDS and dementia. Therefore, potential solutions to the problems identified in this scoping review will be investigated.
The results of this scoping review were discussed in expert interviews (Hüer, 2024, Walendzik, 2025). Experts suggested centralized, easily accessible information on disease risks, symptoms and treatment options. Furthermore, they asked for a directory of suitable service providers. (Walendzik, 2025) A central requirement was the consideration of the special needs and challenges in the medical care of people with intellectual disabilities in the education, further education and training of the professional groups involved in the medical care process (Hüer., 2024).
Limitations
In the context of this review some limitations should be mentioned. First, even if this scoping review aimed to identify deficits and barriers in the medical care of PwDS it also included research focusing in general on people with intellectual impairment. Since it was not always specified which intellectual impairments were considered in individual articles, it is questionable if all problems identified are transferable to the extent mentioned to the target population. However, a critical reflection of the problems in the project consortium should ensure that the problems have a certain relevance in the context of DS and therefore should be considered.
As the studies stem from a narrow range of countries (mostly USA, UK and Ireland), the results are not necessarily relevant for all other systems. Thus, it should be noted, that the further use of our results should take into account the specifics of the respective health care systems. These may, for example, relate to financing or access to healthcare services. Individual problems should be critically examined against the background of existing care in each country. This should be the subject of further research.
Our research includes articles that were published between January 1st 2012 and September 27th 2022. Since then, potentially new relevant articles might have been be published. Due to the time-consuming research method of scoping reviews and the conscientious analysis and preparation of the results as well as the manuscript it was not possible to publish the results earlier. Nevertheless, as in the last year in most countries there were no fundamental changes in the medical care for PwDS, the results are still current and relevant for practice. In our research project, results were used to develop an interview guideline for further qualitative research. Nevertheless, this scoping review should be carried out again in the coming years to check whether new problems have arisen or whether older problems are no longer relevant.
A weakness regarding the methodology is that no agreement rate such as the κ coefficient was tracked during the screening. In cases of disagreement, which were relatively seldom, inclusion or exclusion of concerned articles was discussed in the team of the Institute for Healthcare Management and Research (University Duisburg-Essen). To still guarantee a transparent and comprehensible proceeding, articles screened in full-text with corresponding reasons for exclusion are listed in Appendix 5.
Moreover, this scoping review aimed to map the evidence from the literature, regardless of the quality of the included studies, so we equally mentioned and summarized all problems that were addressed.
Conclusion
Based on literature, medical care for PwDS and dementia seems to be characterized by a variety of different deficits and (access) barriers. In order to improve the care of this vulnerable group, it is necessary to identify appropriate solutions to the problems. Therefore, as part of our “DS-Demenz” research project, we want to identify potential for optimization in order to improve the care of people with DS and dementia. Especially the collaboration between different service providers as well as symptom recognition by caregivers appear useful. However, once the recommendations for action have been finalized, it is necessary for the relevant stakeholders to take action. Governments and medical bodies must take the identified problems and recommendations for action into account, for example in national dementia strategies.
Search strings for the respective databases.
Overview on all included studies.
Problem areas addressed in the studies.
Articles systematized according to problem categories and affected stakeholders.
Screened studies.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Gemeinsamer Bundesausschuss (01VSF21030).
