Determinants of Diagnostic Delay Evaluated in Axial Spondyloarthritis

The mean diagnostic delay in patients with axial spondyloarthritis (axSpA) is still a major challenge in modern rheumatology and is associated with a number of factors, including negative human leukocyte antigen B27 (HLA-B27) status, female gender, presence of psoriasis, and younger age at symptom onset, according to study results published in Rheumatology.

The investigators sought to analyze the factors related to the diagnostic delay of axSpA using a stratified sample of patients in Germany with a diagnosis of axSpA obtained from health insurance data. Participants were questioned regarding demographic, socioeconomic, and SpA-related parameters, including date of symptom onset and date of diagnosis. Participants’ diagnostic delay was calculated as the time from the onset of back pain until a diagnosis of axSpA was made. Factors associated with the diagnostic delay were evaluated using multivariable linear regression analysis.

In the 1677 patients with axSpA included in the analysis, the mean diagnostic delay was 5.7 years (median, 2.3 years). The vast majority of participants (approximately 90%) were age <45 at onset of back pain. Overall, 407 patients were diagnosed with axSpA between 1996 and 2005 and 484 were diagnosed between 2006 and 2015. The diagnostic delay did not differ significantly in either time period. In patients  diagnosed from 1996 to 2005, the mean diagnostic delay was 6.3 years (median, 2.6 years), whereas in patients diagnosed from 2006 to 2015, the mean diagnostic delay was 7.4 years (median, 2.7 years).

According to multivariable linear regression, female gender (β=1.85; 95% CI, 1.06-2.65), negative HLA-B27 status (β=3.61; 95% CI, 2.07-5.14), presence of psoriasis (β=1.40; 95% CI, 0.08-2.73), and younger age at onset of symptoms (β=1.91; 95% CI, 1.53-2.29) were all linked to a longer diagnostic delay in patients with axSpA.

The investigators concluded that specific referral strategies might be needed in order to decrease the delay in diagnosis in certain populations of patients with axSpA.

Reference

Redeker I, Callhoff J, Hoffmann F, et al. Determinants of diagnostic delay in axial spondyloarthritis: an analysis based on linked claims and patient-reported survey data [published online March 21, 2019]. Rheumatology (Oxford). doi:10.1093/rheumatology/kez090