It is increasingly common for people with depression, severe mental illness, or dementia to live with two or more additional physical or mental conditions, (complex multimorbidity). The coexistence of mental and physical disorders limits patientsÂ’ ability to self-manage, often leading to increase doctor consultations and hospitalisation. The aim of the proposed research is to use patient medical records data to describe the most common combination of multiple mental and physical conditions among patients with an existing depression, severe mental illness, or dementia condition. We plan to determine what proportion of these patients have two or more additional conditions and establish how the combinations of these conditions might change over time. We will also investigate whether complex multimorbidity is more common among ethnic minority patients, women, and those from a poor socioeconomic background. Moreover, we will examine the consequences of changes in the number and type of conditions for patientsÂ’ quality of life, employment, and usage of health services, such as the number of GP consultations and how often they are admitted to hospital. Further, we will determine whether unhealthy behaviours, adverse life events, quality of health care, or the number of drugs prescribed are associated with the development of complex multimorbidity. The findings of the project will enable us to propose future intervention strategies to better target interventions for depression, severe mental illness, and dementia patients with complex multimorbidity.
Aims: Mental and physical multimorbidity (MPMM) is projected to triple over the next 15 years, affecting almost 2million young people and adults. Patients with mental and cognitive disorders (M/CD) (e.g. depression, severe mental illness, or dementia) are disproportionately at higher risk of MPMM, defined as two or more coexisting conditions. The proposed study aims to establish the epidemiology of MPMM, its underlying mechanisms, and the impact of current therapeutic and care pathways on MPMM progression and prognosis. Whenever feasible, these aims will be explored separately by gender, ethnicity, and socio-economic status (SES).
Primary exposures: Diagnoses of depression or anxiety, dementia, or severe mental illness (including schizophrenia, bipolar disorders, and schizoaffective disorders).
Outcomes: Primary study outcome will be incidence MPMM events during the study period. In addition, the study will estimate MPMM-related outcomes, including frailty, physical impairment, quality of life, healthcare utilisations, life expectancy, and all-cause mortality.
Study design: Prospective matched cohort study, including a nested case-control study.
Methods: Multivariable longitudinal analyses will be implemented using several statistical techniques, including latent class analysis, Cox proportion hazards regression, multi-state Markov models, linear mixed effects models, and conditional logistic regression.
Linked datasets: ONS Death registration data, Index of Multiple Deprivation (practice and patient level).
Findings: The proposed study will provide novel understanding about mechanistic process responsible for the emergence and poor prognosis of MPMM at different life stages and will allow direct comparison of these processes and outcomes across women, ethnic minorities, and those SES deprived. Such information will inform the development of preventive strategies that are directly relevant for specific populations at greater need of support.
The study primary outcome will be mental and physical multimorbidity (MPM)M, defined as the concurrent existence of two or more physical or mental disorders. Several secondary outcomes will be investigated, including functional impairment (physical disability), frailty, quality of life (QoL), safety outcomes, healthcare utilisation, life expectancy, and all-cause mortality.
Alex Dregan - Chief Investigator - King's College London (KCL)
Alex Dregan - Corresponding Applicant - King's College London (KCL)
Amal Khanolkar - Collaborator - King's College London (KCL)
Amy Ronaldson - Collaborator - King's College London (KCL)
Andrew Pickles - Collaborator - King's College London (KCL)
Emilia Holland - Collaborator - University of Southampton
Jayati Das-Munshi - Collaborator - King's College London (KCL)
Jorge Arias de la Torre - Collaborator - King's College London (KCL)
Mark Ashworth - Collaborator - King's College London (KCL)
Matthew Hotopf - Collaborator - King's College London (KCL)
Rebecca Hoyle - Collaborator - University of Southampton
Simon Fraser - Collaborator - University of Southampton
Louise Coutts - Collaborator - University of Southampton
Mozhdeh Shiranirad - Collaborator - University of Southampton
Patient Level Index of Multiple Deprivation