How Common Is Diagnostic Delay in PsA?

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It is not uncommon for patients with psoriatic arthritis (PsA) to have a delay in diagnosis for 2 or more years, findings of a new study show. And according to the researchers, there had been no significant improvements in the time to diagnosis throughout the study period of 2000 to 2017.

The results were released in conjunction with the American College of Rheumatology’s (ACR) annual meeting, ACR Convergence.

“Early diagnosis of PsA is important for improving long-term outcomes,” the researchers wrote. “Trends in diagnostic delay of PsA in the [United States] and factors associated with delay in diagnosis have not been well studied.”

To evaluate the diagnostic delay and its associated demographic and clinical characteristics, the researchers identified 162 incident PsA cases from 2000 to 2017. The cases all involved patients aged 18 years or older from a geographically defined area who had met the Classification of Psoriatic Arthritis criteria.

The researchers set the following definitions:

• Disease onset: onset of any PsA-related joint symptom as reported by the patient and documented by a physician in the medical records 
• PsA diagnosis date: date of confirmatory diagnosis of PsA by a physician/rheumatologist 
• Diagnostic delay: the time from disease onset to a diagnosis of PsA  

The mean lag time from disease onset to first confirmatory diagnosis by a physician was 2.5 years. Overall, 89 of the 162 patients (54.9%) had a lag time of at least 2 years; such a delay was more common among patients who were younger at the time of diagnosis, who had a higher body mass index, or who had enthesitis before diagnosis. However, diagnostic delay was found to be less common among patients with sebopsoriasis.

The researchers found no significant association of diagnostic delay with gender, education level, smoking status, alcohol intake, psoriasis severity or location, nail involvement, family history of psoriasis or PsA, history of extra-articular manifestations (such as uveitis, inflammatory bowel disease), or high inflammatory markers at the time of diagnosis.

While age- and gender-adjusted logistic regression models showed that radiographic damage may be associated with diagnostic delay, the association did not reach statistical significance.

—Colleen Murphy

Reference:

Karmacharya P, Wright K, Achenbach SJ, et al. Diagnostic delay in psoriatic arthritis: a population based study. Study presented at: American College of Rheumatology Convergence 2020; November 5-9, 2020; Virtual. Accessed October 29, 2020. https://acrabstracts.org/abstract/diagnostic-delay-in-psoriatic-arthritis-a-population-based-study/