The risk of fracture among patients with psoriatic arthritis and psoriasis: a population-based study

Objective To determine the risk of fracture and osteoporosis among patients with psoriatic arthritis (PsA) and psoriasis, compared with the general population and patients with rheumatoid arthritis (RA). Methods A population-based cohort study was performed in The Health Improvement Network in the UK using data from 1994 to 2014. Patients aged 18-89 years with PsA or psoriasis and up to five unexposed controls matched by practice and start date within that practice were included. Patients with RA and matched controls were included for comparison. Severe psoriasis was defined by a code for psoriasis and either phototherapy or a systemic medication for psoriasis. Incidence and adjusted HRs (aHR) for fracture (all, hip, vertebral) were calculated. Results Patients with PsA (n=9788), psoriasis (n=158 323) and controls (n=821 834) were identified. Patients with PsA had an elevated risk of all fracture aHR 1.26 (1.06 to 1.27). Patients with mild psoriasis had elevated risk of all fractures, vertebral and hip fracture: aHR 1.07 (1.05 to 1.10), 1.17 (1.03 to 1.33) and 1.13 (1.04 to 1.22). Patients with severe psoriasis had significantly elevated risk of all fracture and vertebral fracture: aHR 1.26 (1.15 to 1.39) and 2.23 (1.54 to 3.22). Conclusions PsA and psoriasis are associated with an elevated risk for fracture.