Severe mental illness as a risk factor for recorded diagnosis of osteoporosis and fragility fractures in people aged ≥50 years: 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 To examine the association between SMI and recorded diagnosis of osteoporosis and fragility fracture in people aged >= 50 years. Design and setting Population-based cohort study set in UK primary care. Method Anonymised primary care data (IQVIA Medical Research Database) were used. Patients with a diagnosis of SMI aged 50-99 years (2000-2018) were matched to individuals without SMI. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Analyses were stratified by sex and age, accounting for social deprivation, year, smoking, alcohol, and body mass index. 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 an osteoporosis diagnosis, with differences mainly observed among the youngest (aged 50-54 years: HR 2.12, 95% CI = 1.61 to 2.79) and the oldest (aged 85-99 years: HR 2.15, 95% CI = 1.05 to 4.37), and SMI increased the risk of fragility fractures across all ages. In women, SMI increased the risk of an osteoporosis diagnosis only in those aged 50-54 years (HR 1.16, 95% CI = 1.01 to 1.34), but increased the risk of fragility fractures across all ages. There were more than twice as many men with SMI with fragility fracture records than with an osteoporosis diagnosis: fragility fracture:osteoporosis = 2.10, compared with fragility fracture:osteoporosis = 1.89 in men without SMI. The fragility fracture:osteoporosis ratio was 1.56 women with SMI versus 1.11 in women without SMI. Conclusion SMI is associated with an increased likelihood of fragility fractures and osteoporosis underdiagnosis. Interventions should be considered to mitigate the increased risk of fractures in people with SMI.