Abstract
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 in 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.