Related Experiment Video
Updated: May 16, 2026
Measuring Psoriasis Severity at Home
Published on: March 1, 2024
Prevalence and treatment patterns of psoriatic arthritis in the UK
Alexis Ogdie1, Sinéad Langan, Thorvardur Love
1Division of Rheumatology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, 8 Penn Tower, 1 Convention Ave, Philadelphia, PA 19104, USA. alexis.ogdie@uphs.upenn.edu
Insights
The prevalence of psoriatic arthritis (PsA) in the UK is 0.19%, with higher rates in severe psoriasis patients. This study highlights key factors associated with PsA development.
Area of Science:
- Rheumatology
- Epidemiology
- Public Health
Background:
- Psoriatic arthritis (PsA) is a chronic inflammatory condition.
- Understanding PsA prevalence and associated factors is crucial for public health initiatives.
Purpose of the Study:
- Determine PsA prevalence in the UK using The Health Improvement Network (THIN) database.
- Identify factors associated with PsA in psoriasis patients.
- Describe disease-modifying antirheumatic drug (DMARD) use in PsA patients.
Main Methods:
- Cross-sectional study of 4.8 million patients aged 18-90 in THIN.
- Subcohort analysis of 4900 psoriasis patients aged 45-65.
- Logistic regression used to assess associations for prevalent PsA.
Main Results:
- Overall PsA prevalence was 0.19% (9045/4.8 million).
- PsA prevalence was 8.6% in confirmed psoriasis patients.
- Severe psoriasis, obesity, and psoriasis duration ≥10 years were associated with higher PsA prevalence.
Conclusions:
- PsA prevalence in THIN aligns with prior estimates.
- THIN is a valuable resource for PsA research.
- PsA diagnosis relied on diagnostic codes, not CASPAR criteria.
Objectives:
The objectives of this study were to determine the prevalence of PsA in The Health Improvement Network (THIN), a large population-based medical records database in the UK, to examine factors associated with prevalent PsA among patients with psoriasis and to describe the use of DMARDs in patients with PsA.
Methods:
Two cohorts were derived from THIN to examine the prevalence of PsA in a cross-sectional study among all patients aged 18-90 years and among a subcohort of 4900 psoriasis patients aged 45-65 years. Prescription codes were used to describe therapies after the diagnosis of PsA. Associations for prevalent PsA among psoriasis patients were assessed using logistic regression analysis.
Results:
Among 4.8 million patients in THIN between the ages of 18 and 90 years, 9045 patients had at least one medical code for PsA, giving an overall prevalence of 0.19% (95% CI 0.19%, 0.19%). Of those patients, 45.9% with PsA have been prescribed DMARDs. Among the 4064 confirmed psoriasis patients, the prevalence of PsA was 8.6% (95% CI 7.7%, 9.5%). PsA was more prevalent among patients with severe psoriasis [odds ratio (OR) 3.34; 95% CI 2.40, 4.65], obesity (OR 1.77; 95% CI 1.30, 2.41) and duration of psoriasis for ≥10 years (OR 7.42; 95% CI 3.86, 14.25) in the fully adjusted model.
Conclusion:
The prevalence of PsA in THIN is consistent with previous population-based estimates. Limitations include a definition of PsA based on a diagnostic code rather than Classification Criteria for Psoriatic Arthritis (CASPAR) criteria. Given the large population of PsA patients, THIN is an important resource for the study of PsA.
