Mental healthcare utilisation and costs before and after dementia diagnosis: evidence from electronic health records

Objectives: To describe secondary mental healthcare utilisation and associated costs among patients diagnosed with dementia or mild cognitive impairment (MCI). Design: Retrospective cohort study using routinely collected electronic health record data. Setting: Secondary mental healthcare services within a large NHS mental health provider in South London, UK. Participants: Adults aged 18 years or older with a recorded diagnosis of dementia or MCI between 1 January 2010 and 31 December 2020. Patients surviving less than one year after diagnosis were excluded. The final cohort comprised 16,081 individuals. Primary and secondary outcome measures: Service utilisation and NHS mental health service costs during the 12 months before and after diagnosis, including inpatient, outpatient and memory clinic contacts. Results: The proportion of patients with at least one recorded mental health service contact declined from 91% in the 12 months before diagnosis to 69% after diagnosis. Among service users, mean NHS mental health costs increased from GBP 1,497 to GBP 2,177 per person following diagnosis (mean increase GBP 680; p<0.001), driven primarily by inpatient care. Dementia diagnosis, younger age, male gender, living alone, greater cognitive impairment and higher clinical symptom burden were independently associated with higher costs. Ethnic differences in service use and costs were also observed. Conclusions: Although overall service engagement declined following diagnosis, costs increased among those continuing to access care, indicating greater intensity of service use. Understanding patterns of secondary mental healthcare utilisation and associated costs may help inform planning and resource allocation within dementia services.