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New evidence shows that almost one fifth of people with dementia also have other serious conditions such as stroke, diabetes and visual impairment. Services are not currently designed to provide adequate integrated care for people with dementia plus other conditions. For instance, people with dementia are less likely to get diabetes checks or cataract surgery than those without dementia. Carers are not routinely contacted, and there is a lack of guidance for health professionals covering more than one condition.

Implications for practice include incorporating the impact of a diagnosis of dementia on pre-existing conditions into care planning. Second, professionals could find ways to communicate more effectively with family and carers, such as agreeing to share health information with carers while a person still has capacity to decide. Third, there could be specific advice in guidelines for professionals such as those for diabetes and stroke management.

Why was this study needed?

There are around 800,000 people in the UK with dementia, and two thirds of people with dementia live at home. There may be as many as 670,000 people in the UK who are the main carers for people with dementia.

Dementia is associated with complex needs, especially in the later stages, including high levels of dependency and morbidity. These complex care needs often challenge the skills and capacity of carers and services.

People with dementia often have other medical conditions (comorbidity), but it is difficult to know the size of this problem. We also do not know enough about the effects of having multiple conditions on patient needs, quality of patient care or how services are adapting to meet the needs of this population.

This study looked at the impact of also having other conditions for a person with dementia on access to non-dementia services, and aimed to identify ways of improving services for these people.

What did this study do?

This NIHR-funded study aimed to look at the effects of having multiple conditions on the quality of patient care, patient needs and whether services are adapting to these needs.

It focused particularly on three conditions; diabetes, stroke and visual impairment.

First, the authors conducted a scoping literature review of 76, mainly observational, studies covering rates of comorbidity, access to services and integration across services.

Then, the authors analysed a large database of records from over 13,000 people aged over 65 in England and Wales, living at home and recorded as having dementia. This helped them to estimate prevalence of other health problems, and health and social service use.

Finally, they undertook interviews and focus groups to explore the views and experiences of 28 people with dementia and any of the three additional conditions (diabetes, stroke or vision impairment). They also interviewed 33 family carers and 56 health professionals for this part of the study.

What did it find?

The review found:

  • People with dementia have quite high rates of comorbidity based on 31 different studies. An estimated 13-20% of people with dementia have diabetes, and 16-19% have stroke.
  • People with dementia had poorer access to services than those without dementia.
  • There was lack of healthcare system continuity for people with dementia and comorbidity, with little integration or communication between different teams and specialties.

Analysis of the database found:

  • 17% of people with dementia had diabetes, 18% had experienced a stroke and 17% had some form of visual impairment.
  • There has been an increase in unpaid care and hospital use over the past ten years.

This information came from six England / Wales regions only, so there is a need for new population-based data.

The interviews and focus groups found:

  • Communication was often poor and without a standardised approach to sharing information about a person’s dementia and how it might affect the management of other conditions.
  • Providing continuity of care (including relationships and information management) and access to care (including comprehensiveness) was important.
  • Systems are not designed to involve family carers in decision-making.
  • Healthcare professionals reported not routinely involving carers in appointments or decision-making processes.
  • There is a lack of guidance for health professionals for making decisions about care, for example weighing up the risks and benefits of treatment.

What does current guidance say on this issue?

NICE has guidance on Dementia: supporting people with dementia and their carers in health and social care (2006) which also states that modifiable risk factors such as diabetes should be reviewed in people with dementia as a preventative measure and, if appropriate, treated. There is no specific guidance included for people with dementia and vision impairment or stroke.

NICE guidance on diabetes and stroke management does not include guidance on diagnosing and managing dementia for people with these conditions.

The Department of Health’s Better care for people with two or more long term conditions is a framework of principles for system wide action. The 2015 Health and Social Care Act in England requires local authorities to assess the needs of carers for support and services such as emotional support, help with day-to-day care and planned respite care. It includes incentives for general practitioners to identify carers and review their wellbeing and needs.

What are the implications?

This study shows that significant numbers of people with dementia have conditions such as stroke, diabetes and vision impairment. It found that dementia complicates the delivery of appropriate services and magnifies the difficulties that people with long-term conditions experience. It also shows that systems are not currently designed to involve carers to the degree they should be.

The authors suggest the impact of a diagnosis of dementia on pre-existing conditions should be incorporated into care planning and guidelines such as for diabetes and stroke management. They also recommend such things as dementia training for staff at all levels, and longer appointments for people with dementia in both primary and secondary care. Furthermore, an awareness that people with dementia plus other conditions that do not have support may need additional assistance.

This study is featured in an NIHR Dissemination Centre Highlight on support for dementia carers, bringing together a range of research projects funded by NIHR.


Citation and Funding

Bunn F, Burn A-M, Goodman C, et al. Comorbidity and dementia: a mixed-method study on improving health care for people with dementia (CoDem). Health Serv Deliv Res. 2016;4(8).

This project was funded by the National Institute for Health Research Health Services and Delivery Research programme (project number 11/1017/07).



Bunn F, Burn AM, Goodman C, et al. Comorbidity and dementia: a scoping review of the literature. BMC Medicine. 2014;12:192.

DH. Comorbidities: a framework of principles for system-wide action. London: Department of Health; 2014.

NICE. Dementia: supporting people with dementia and their carers in health and social care. CG42. London: National Institute for Health and Care Excellence; 2006.

NICE. Stroke rehabilitation in adults. CG162. London: National Institute for Health and Care Excellence; 2013.

NICE. Type 1 diabetes in adults: diagnosis and management. NG17. London: National Institute for Health and Care Excellence; 2015.

NICE. Type 2 diabetes in adults: management. NG28. London: National Institute for Health and Care Excellence; 2015.

Produced by the University of Southampton and Bazian on behalf of NIHR through the NIHR Dissemination Centre


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Expert commentary

Around 80% of people with dementia are over 75 years and also have other illnesses. This important study finds people with dementia have particular difficulty in navigating health services, and providers often did not involve or inform family, despite knowing their help was crucial. Good practice was individual, not part of a system, as pathways and guidelines for other common illnesses ignored dementia. Thus physical health deteriorated more rapidly.There is considerable research to be done about solutions. I suggest one immediate, low-tech and cheap measure is to make sharing information the default option, by asking people with dementia, at first health contact for a new problem, for permission to share information with particular family members. We do this and most people give permission while they have the decisional capacity.Gill Livingston, Professor of Psychiatry of Older People, Division of Psychiatry, University College London 
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