Takeaway
- This study found an increased risk of osteoarthritis (OA) in patients with psoriatic arthritis (PsA) compared with patients with psoriasis and those in the general population.
Why this matters
- Future studies are warranted to determine whether these findings reflect a true increase in OA risk in patients with PsA or whether it can be explained by differences in the opportunity for OA diagnosis between the different cohorts, an initial misdiagnosis of PsA or a combination of both.
Study design
- In this population-based study, 6783 patients with incident PsA (age, 18-89 years) were identified from the UK Clinical Practice Research Datalink and matched to 27,132 patients from the general population and 27,132 psoriasis patients.
- Primary outcome: diagnosis of OA of any site.
- Funding: National Institute for Health Research.
Key results
- The baseline prevalence of OA was:
- 22.1% (95% CI, 21.1-23.1%) in the PsA cohort;
- 12.6% (95% CI, 12.2-13.0%) in the psoriasis cohort; and
- 11.0% (95% CI, 10.6-11.3%) in the general population cohort.
- The incidence of OA ranged from 162.4 per 10,000 person-years in the PsA cohort to 117.1 in the psoriasis cohort and 109.2 per 10,000 person-years in the general population cohort.
- The incidence of OA was significantly higher in the PsA cohort than psoriasis and general population cohorts after adjustment for body mass index (adjusted relative risk [aRR], 1.68; 95% CI, 1.46-1.93 and aRR, 1.86; 95% CI, 1.62-2.14).
- Sensitivity analyses found this reduced to aRR, 1.39 (95% CI, 1.18-1.63) and aRR, 1.55 (95% CI, 1.31-1.83) when looking at OA diagnoses starting at least one year after the index date.
Limitations
- Only around 50% of patients with OA diagnosis had a code that specified the actual site.
This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.