Care trajectories before and after a first diagnosis of dementia in patients with schizophrenia or bipolar disorders

Context:

A first diagnosis of dementia further complexifies the healthcare needs of older adults living with severe mental illness. While these individuals have complex healthcare needs and are at higher risk of cognitive impairments, there is no evidence of how their patterns of healthcare use vary over time around the dementia diagnosis.

Objective:

We aimed to explore the care trajectories (CTs) of older adults living with severe mental illness one year before and one year after a first dementia diagnosis.

Study Design and Analysis

This is a retrospective cohort study using an innovative multidimensional state sequence analysis approach to develop a typology of CTs.

Dataset

We used health administrative data from the Quebec (Canada) provincial health insurance board (1996- 2016).

Population Studied

The cohort included all patients aged 65 years and older who received a first diagnosis of dementia (index date) in 2014-2016 and were previously diagnosed with schizophrenia or bipolar disorder.

Outcome Measures

We measured CTs according to 1) healthcare settings (e.g., hospital, emergency department, clinic); 2) reasons for healthcare use (e.g., dementia, other mental and non-mental diagnoses), and 3) healthcare professionals (e.g., dementia specialists, psychiatrists, home care professionals).

Results

A total of 3,868 patients were categorized into seven distinct types of CTs. Type 1 (47.6%) showed the lowest healthcare use and comorbidities. Type 2 (9.9%) and type 3 (63.0%) showed high healthcare and home care use after dementia diagnosis. A high comorbidity and stable healthcare use characterized type 4 (10.3%). Type 5 (9.0%) comprised younger individuals with the highest intensity of mental health-related and psychiatric consultations. Type 6 (10.9%) and type 7 (5.9%) presented a high home care use pattern for non-mental reasons before the dementia diagnosis. The year after, type 6 showed the highest long-term care (37.1%) and death (48.5%) rates, while they remained lower for type 7.

Conclusions

Our innovative approach provides a unique insight into the complex healthcare patterns of people living with serious mental illness and dementia. It provides an avenue to support data-driven decision-making by highlighting fragility areas in the allocation of care resources.