Assessment and management pathways of older adults with mild cognitive impairment: descriptive review and critical interpretive synthesis
Authors: Chambers Duncan , Cantrell Anna , Sworn Katie , Booth Andrew 
Published: May 2022

Background
Mild cognitive impairment in older adults is a risk factor for dementia. Mild cognitive impairment is a result of a diverse range of underlying causes and may progress to dementia, remain stable or improve over time.

Objectives
We aimed to assess the evidence base around the assessment and management pathway of older adults with mild cognitive impairment in community/primary care, hospital and residential settings.

Data sources
In January 2021, we searched MEDLINE, EMBASE, PsycInfo®, Scopus, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library (i.e. Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials), Science Citation Index and Social Science Citation Index. The search was limited to studies published in English between 2010 and 2020. Grey literature and citation searches were also performed.

Methods
We performed two separate evidence reviews: (1) a descriptive review with narrative synthesis focusing on diagnosis, service provision and patient experience; and (2) a critical interpretive synthesis of evidence on the advantages and disadvantages of ‘mild cognitive impairment’ as a diagnostic label.

Results
A total of 122 studies were included in the descriptive review, of which 29 were also included in the critical interpretive synthesis. Study participants were most commonly recruited from populations of community-living older adults or those who had sought medical help from their general practitioner for memory problems. Follow-up searching identified a further 11 studies for the critical interpretive synthesis. The descriptive review identified multiple barriers to efficient diagnosis, starting with patient reluctance to seek help. General practitioners have a variety of cognitive tests available, but substantial numbers of patients meeting criteria for dementia do not have a diagnosis recorded. Patients may be referred to a memory clinic, but these clinics are mainly intended to identify and support people with dementia, and people with mild cognitive impairment may be discharged back to their general practitioner until symptoms worsen. Availability of scanning and biomarker tests is patchy. Qualitative studies show that patients with mild cognitive impairment and their carers find the process of investigation and diagnosis difficult and frustrating to negotiate. The key finding from the critical interpretive synthesis was that the need for a ‘timely’ diagnosis outweighs the ongoing debate about the value, or otherwise, of early investigation and labelling of memory problems. Determining what is a timely diagnosis involves balancing the perspectives of the patient, the health system and the clinician.

Conclusions
The two reviews reported here have applied different ‘lenses’ to the same body of evidence. Taken together, the reviews highlight the importance of a timely diagnosis for memory problems and identify barriers to obtaining such a diagnosis, from reluctance to seek help through to patchy availability of advanced diagnostic tests.

Limitations
The review was primarily descriptive, reflecting the prespecified review questions. Study selection was complicated by lack of a consistent definition of mild cognitive impairment and its overlap with other memory disorders. It was not possible to employ double study selection, data extraction or quality assessment, although processes of checking and verification were used throughout the review.

Future work
Priorities include evaluating remote methods of memory assessment and preparing for the likely future availability of disease-modifying treatments for early dementia. Research is needed on the investigation of memory problems in hospital and social care settings.

Study registration
This study is registered as PROSPERO CRD42021232535.

Funding
This project was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme and will be published in full in Health and Social Care Delivery Research; Vol. 10, No. 10. See the NIHR Journals Library website for further project information.