RT Journal Article SR Electronic T1 Risk of osteoarthritis in an incident cohort of people with psoriatic arthritis: a population-based cohort study JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.200564 DO 10.3899/jrheum.200564 A1 Rachel Charlton A1 Amelia Green A1 Gavin Shaddick A1 Julia Snowball A1 Alison Nightingale A1 William Tillett A1 Catherine Smith A1 Neil McHugh YR 2020 UL http://www.jrheum.org/content/early/2020/11/10/jrheum.200564.abstract AB Objective To determine the risk of a diagnosis of osteoarthritis (OA) in psoriatic arthritis (PsA) patients compared to patients with psoriasis and a general population cohort. Methods Incident PsA patients aged 18-89 years at diagnosis were identified from the UK Clinical Practice Research Datalink between 1998 and 2014. All PsA patients were matched to two cohorts of patients both at a 1:4 ratio. The first cohort included patients with psoriasis (and no PsA) and the second was a general population cohort (with no psoriasis or PsA). The baseline prevalence of OA was calculated for each study cohort. The incidence of OA was calculated and adjusted relative risks (RRadj) were calculated using conditional Poisson regression. Results We identified 6,783 incident PsA patients. The baseline prevalence of OA ranged from 22.1% (CI9521.1-23.1) in the PsA cohort to 12.6% (CI9512.2-13.0) and 11.0% (CI9510.6- 11.3) in the psoriasis and general population cohorts respectively. The incidence of OA was significantly higher in the PsA cohort compared to the psoriasis and general population cohorts after adjusting for BMI (RRadj 1.68 CI951.46-1.93 and RRadj 1.86 CI951.62-2.14 respectively). Conclusion An increased risk of OA was observed in patients with PsA compared to patients with psoriasis alone and those in the general population. Further work is needed to determine whether this reflects a true increase in OA risk or misdiagnosed PsA and the extent to which it can be explained by differences in the opportunity for OA diagnosis between cohorts.