Severe Mental Illness as a risk factor for recorded diagnosis of osteoporosis and fragility fractures in people aged 50 and above: retrospective cohort study using UK primary care data

Background: Severe Mental Illness (SMI) has been associated with reduced bone density and increased risk of fractures, although some studies have shown inconsistent results.

Aim: Examine the association between SMI and recorded diagnosis of osteoporosis (OP) and fragility fracture (FF) in people aged ≥50years.

Design and Setting: Population-based cohort study; UK Primary care.

Method: We used anonymised primary care data (IQVIA Medical Research Database). Patients with a diagnosis of SMI aged 50-99y (2000-2018) were matched to individuals without SMI. We used Cox Proportional Hazards models to estimate Hazard Ratios (HR) and 95% Confidence Intervals (95%CI). We stratified analyses by sex and age, accounting for social deprivation, year, smoking, alcohol, and Body Mass Index (BMI).

Results: In total 444,480 people were included (SMI N=50,006; unexposed N=394,474). In men, diagnosis of SMI increased the likelihood of OP diagnosis, with differences mainly observed amongst the youngest (50-54y:HR=2.12;95%CI 1.61-2.79) and oldest (85-99y:HR=2.15;95%CI 1.05-4.37), and also increased the risk of FF across all ages. In women, SMI increased the risk of OP diagnosis only in those aged 50-54y:HR=1.16;95%CI 1.01-1.34, but increased the risk of FF across all ages. There were more than twice as many men with SMI with FF records than with OP diagnosis: FF:OP=2.10, compared to FF:OP=1.89 in men without SMI. The FF:OP ratio was 1.56 in women with SMI vs.1.11 in women without SMI.

Conclusion: SMI is associated with increased likelihood of fragility fractures and osteoporosis underdiagnosis. Interventions should be considered to mitigate the increased risk of fractures in people with SMI.