Diagnostic Delay in Psoriatic Arthritis: A Population-based Study.

OBJECTIVE: To examine demographic and clinical characteristics associated with diagnostic delay in psoriatic arthritis (PsA). METHODS: We characterized a retrospective, population-based cohort of incident adult (≥ 18 yrs) patients with PsA from Olmsted County, Minnesota, from 2000-2017. All patients met the classification criteria. Diagnostic delay was defined as the time from any patient-reported PsA-related joint symptom to a physician diagnosis of PsA. Factors associated with delay in PsA diagnosis were identified through logistic regression models. RESULTS: Of the 164 incident PsA cases from 2000 to 2017, 162 had a physician or rheumatologist diagnosis. Mean (SD) age was 41.5 (12.6) years and 46% were female. Median time from symptom onset to physician diagnosis was 2.5 years (IQR 0.5-7.3). By 6 months, 38 (23%) received a diagnosis of PsA, 56 (35%) by 1 year, and 73 (45%) by 2 years after symptom onset. No significant trend in diagnostic delay was observed over calendar time. Earlier age at onset of PsA symptoms, higher BMI, and enthesitis were associated with a diagnostic delay of > 2 years, whereas sebopsoriasis was associated with a lower likelihood of delay. CONCLUSION: In our study, more than half of PsA patients had a diagnostic delay of > 2 years, and no significant improvement in time to diagnosis was noted between 2000 and 2017. Patients with younger age at PsA symptom onset, higher BMI, or enthesitis before diagnosis were more likely to have a diagnostic delay of > 2 years, whereas patients with sebopsoriasis were less likely to have a diagnostic delay.