Abstract
Background and Aims: The prevalence of dementia is rising globally, however, it is estimated that only 60% of people living with dementia in the UK have a formal diagnosis. Over the last decade many countries have taken proactive policy approaches to manage the care and treatment of dementia. They have placed particular emphasis on the “timely” or “early” diagnosis of dementia to enable people with dementia to live well for longer. However, without a reliable diagnostic test for dementia and very few effective treatments, it is unclear what benefits an early diagnosis can be expected to produce.Therefore, the overall aim of this thesis is to explore the potential benefits of diagnosing dementia early. It is difficult to distinguish an “early” diagnosis from a late diagnosis. Therefore, this thesis aimed to explore whether a diagnosis of Mild Cognitive Impairment (MCI) before dementia could be used as a proxy for early diagnosis, and if an early diagnosis was associated with a reduced risk of mortality, hospitalisation, or emergency department attendance. Furthermore, as previous research has not examined the benefits of an early diagnosis from the perspective of people living with dementia, this thesis aimed to address this gap in the literature. Additionally, non-pharmacological treatments are an important tool in the clinical management of dementia, however, it is not clear how they might benefit people in the early stages of dementia. Therefore, this thesis aimed to explore which outcomes are used in randomised controlled trials testing novel non-pharmacological treatments for mild dementia and mild cognitive impairment.
Methods: This thesis used a convergent parallel mixed methods design, consisting of three phases of investigation.
The first phase was a quantitative study, analysing data extracted from the medical records of 18,555 patients diagnosed with dementia by South London and Maudsley NHS Trust. This phase examined the relationship between an early diagnosis of dementia and hospitalisation, emergency department attendance, and mortality. The second phase consisted of a qualitative study using semi-structured interviews and thematic analysis, exploring 2 people living with dementia and 12 caregiver’s perceptions of the benefits of diagnosing dementia early. The final phase was a scoping review of outcome measures used by 92 trials testing non-pharmacological treatments for mild dementia and MCI. The findings from the three phases of investigation were integrated using the triangulation protocol to create cross-cutting meta-themes.
Findings: A diagnosis of MCI before dementia was deemed to be a useful proxy for an early diagnosis. A small proportion (5.6%) of participants in the quantitative phase received an early diagnosis. Those with an early diagnosis had a reduced risk of mortality (HR = 0.86, CI = 0.77–0.97), however, there was no difference in the risk of hospitalisation (HR= 0.99, CI= 0.91 – 1.08), and they were at increased risk of attending the emergency department (HR= 1.09, CI= 1.00 – 1.18). The results from the qualitative study showed that an early diagnosis enabled people living with dementia and their caregivers to “identify and respond to the evolving needs of the person living with dementia”. More specifically, the benefits of an early diagnosis included: understanding early symptoms and/or behaviours to prevent crisis, timely decision making which involves or respects the needs of the person living with dementia, and access to services and treatments to manage decline. However, caregivers felt certain enablers needed to be in place for these benefits to be felt. These included: adequate prognostic information and disease-modifying treatments, the presence of a caregiver, and a willingness to accept the diagnosis or post-diagnostic support. The scoping review charted 358 outcome measures used in RCTs for new non-pharmacological treatments. Only 78 (22%) of these measures were used more than once. Researchers have prioritised cognitive outcomes over measuring quality of life, making it difficult to assess whether early treatments can keep people with dementia living well for longer. The integration of results, using the triangulation protocol, produced four meta-themes capturing the potential benefits of an early diagnosis. These meta-themes vary in the degree to which they are supported by evidence from this thesis.
1)An early diagnosis could initiate early treatment; however, there are gaps in our understanding of the benefits. I found that people with an early diagnosis were more likely to be prescribed anti-dementia drugs, which was welcomed by participants in the qualitative study. However, more research is needed to determine the benefits of initiating early treatment.2)An early diagnosis can enable people to live for longer. I found people with an early diagnosis had an increased survival, however living for longer may not be perceived as a benefit by those living with dementia and their caregivers.3)An early diagnosis can reduce the risk of hospitalisation or emergency department attendance. I found participants in the qualitative study felt that an early diagnosis could lead to more responsive treatments from health services. However, the quantitative study found that people with an early diagnosis were at increased risk of attending the emergency department.4)The benefits of an early diagnosis are dependent on individual and sociological factors. I found that the benefits of an early diagnosis were dependent on individual factors such as the willingness to accept the diagnosis of dementia and the presence of a caregiver; and sociological factors including ethnicity and socio-economic status.
Conclusion: The findings of this thesis indicate that the benefits of an early diagnosis are not as straight forward as previously thought. There is the potential for an early diagnosis to improve outcomes for people living with dementia, however, this is highly dependent on contextual factors and the provision of post-diagnostic support. Future research is needed to understand how dementia policy, services, and treatments can be improved to maximise their impact on people living with dementia.
Date of Award | 1 Oct 2021 |
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Original language | English |
Awarding Institution |
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Supervisor | Matthew Prina (Supervisor) & Vanessa Lawrence (Supervisor) |