Retrospective Analysis of the Impact of Screening for Psoriatic Arthritis (PsA) with the Psoriasis Epidemiology Screening Tool (PEST) in Clinical Dermatology Practice

Abstract

Introduction: Patients with plaque psoriasis (PSO) have an increased risk of developing PsA as the disease severity progresses. While it is estimated that 30% of patients with PSO have PsA, nearly 16% of patients with PSO may have undiagnosed PsA.1,2 Implementing the PEST questionnaire for PsA screening in dermatologic practice may increase early intervention by improving rates of timely diagnosis.3 This observational study aimed to assess the proportion of patients with PSO and no previous PsA diagnosis who screened positive on the PEST and were then diagnosed with PsA by a healthcare provider in the PEST deployment period within the Advanced Dermatology and Cosmetic Surgery (ADCS) specialty dermatology network. Procedure/Study: De-identified, real-world patient data [2018–2019 and 2021–2022] were sourced from electronic health records within the ADCS network of outpatient facilities across 14 states in the United States. Patients were included in the analysis if they received care at an ADCS facility where the PEST was deployed, had ≥1 encounter with a diagnosis code for PSO, and never had a diagnosis code for PsA before their first diagnosis code for PSO. For outcomes directly related to PEST evaluations, data from 1/1/2021–12/31/2022 (PEST deployment period) were used. For outcomes not directly related to PEST results, data from 1/1/2018–12/31/2019 (period before PEST deployment) were evaluated. Descriptive statistics, including frequencies, percentages, and 95% confidence intervals (CIs) for categorical variables, were used to characterize the patient cohorts by study period. Results: Among ADCS facilities using the PEST during the deployment period (44% of practices in the network), the final study population included 14,308 and 21,142 patients with PSO in the period before PEST deployment and during the PEST deployment period, respectively. In the PEST deployment cohort, 1,100 (5.2%; 95% CI: 4.9–5.5) patients were screened using the PEST. In the period before PEST deployment, 327 (2.3%; 95% CI: 2.0–2.5) patients with PSO and no previous PsA diagnosis were subsequently diagnosed with PsA. During the PEST deployment period, 449 (2.1%; 95% CI: 1.9–2.3) patients with PSO and no previous PsA diagnosis received a subsequent PsA diagnosis without PEST screening. Of all patients with PSO who screened positive for PsA on the PEST (score ≥3; n=296), 10.8% (n=32; 95% CI: 7.6–15.1) subsequently received a formal PsA diagnosis during the PEST deployment period. Conclusion: These results suggest that a meaningful proportion of patients with PsA may be underdiagnosed in the dermatology setting. Deployment of the PEST in the clinical dermatologic workflow may provide an opportunity to diagnose PsA earlier and improve patient outcomes.