Long-term chronic conditions in individuals with mental and behavioural disorders: A data linkage study

Objective: This study aimed to investigate the physical health conditions among health service users in the first year since recorded mental disorder diagnosis in Western Australia. Methods: Community mental health, emergency department (ED) and inpatient records of individuals aged ⩾ 18 years with a recorded mental disorder diagnosis in state-funded health services were analysed. We identified long-term physical health conditions recorded within the first year of the first recorded mental disorder diagnosis. Prevalence of physical comorbidity across time was estimated using multinomial logistic regression. Mean number of health service contacts in the first year of the recorded mental disorder diagnosis was obtained using generalised linear model. Results: Altogether, 253,362 individuals were included. Within the first year of the first recorded mental disorder, the prevalence of at least one physical comorbidity ranged from 20.0% in 2006 to 14.5% in 2020. Cardiovascular disease was the most common comorbidity, but the most common combinations of comorbidities became more varied over time. The number of ED and inpatient contacts were higher in subgroups with a higher number of physical comorbidities (ED contacts: 2.4 [95% confidence intervals: 2.4, 2.4] for no comorbidities to 3.6 [3.4, 3.8] for ⩾ 3 comorbidities; inpatient contacts: 2.6 [2.6, 2.7] for no comorbidities to 4.5 [4.1, 4.9] for ⩾ 3 comorbidities). Conclusion: With a substantial proportion of individuals with mental disorders already having physical comorbidities on their first year of contact with state-funded health services, and the comorbidity combinations becoming more diverse, there is a need to implement more comprehensive joint mental and physical health services.