Clinical Manifestations.

Background: Dementia is associated with a range of non-cognitive features that can occur during the prodromal phase. Improved recognition of non-cognitive presentations of dementia could reduce inequalities in dementia diagnosis, particularly if sociocultural factors influence rates of help-seeking for cognitive symptoms. We aimed to investigate presentations to primary care in the years before dementia diagnosis in a deprived and ethnically diverse population with universal access to health care.

Method: We conducted a nested case-control study using electronic health care records on 1,016,277 individuals from primary care practices in East London, UK between 1990 and 2018. Individuals with a diagnosis of dementia were compared to controls without dementia. We ran a matched analysis (four controls matched to each person with dementia according to age and sex) using multivariable logistic regression to assess the associations between pre-diagnostic presentations to primary care with subsequent diagnosis of dementia. We analysed three time periods (<2, 2-5, 5-10) before diagnosis.

Result: We included 4,137 individuals and 15,754 controls in the matched analysis (51.8% White; 42.7% Black, South Asian and other ethnicities). Neuropsychiatric presentations including depression (odds ratio [OR] = 2.71; 95% CI: 2.33 to 3.16), anxiety (OR = 1.67; 95% CI: 1.46 to 1.92), initiation of antipsychotic medication (as a proxy for psychotic symptoms) (OR = 5.84; 95% CI: 4.80 to 7.11) and insomnia (OR = 1.69; 95% CI: 1.31 to 2.17) were more frequent in the years before dementia diagnosis. Associations were found for autonomic features including constipation (OR = 1.54; 95% CI: 1.39 to 1.71) and incontinence (OR = 2.63; 95% CI: 2.32 to 2.97) up to a decade, and hypotension (OR = 1.89; 95% CI: 1.35 to 2.63) up to five years before dementia diagnosis. Sensory features including hearing loss (OR = 1.36; 95% CI: 1.14 to 1.63), imbalance and dizziness were also associated with subsequent dementia diagnosis. Memory difficulty was more strongly associated with subsequent dementia diagnosis than any non-cognitive presentation (OR = 51.00; 95% CI: 43.87 to 59.29).

Conclusion: A range of non-cognitive presentations are seen during the prodromal period of dementia in a diverse population. Improved recognition of these associations could increase access to dementia diagnosis, through improved recognition of potential presenting symptoms in people from different backgrounds.