Determinants of diagnostic delay in axial spondyloarthritis: an analysis based on linked claims and patient-reported survey data

Abstract

Objectives: The objective of this study was to assess the current diagnostic delay in axial SpA (axSpA) and to analyse factors associated with it.

Methods: A stratified sample of subjects with a diagnosis of axSpA (International Classification of Diseases, 10th Revision code M45) was drawn from health insurance data in Germany and was questioned on disease-related, lifestyle and socio-economic characteristics. The diagnostic delay was calculated as the time from back pain onset until a diagnosis of axSpA. A multivariable linear regression analysis was performed to explore factors associated with the diagnostic delay.

Results: Among 1677 patients with axSpA included in the analysis, the mean diagnostic delay was 5.7 years (median 2.3). Of those, 407 patients were diagnosed in 1996-2005 and 484 patients in 2006-2015. The mean diagnostic delay was not substantially different in both periods: 6.3 years (median 2.6) and 7.4 (2.7), respectively. Multivariable linear regression revealed that female sex [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 symptom onset [β = 1.91 (95% CI 1.53, 2.29)] were factors associated with a longer diagnostic delay.

Conclusion: The diagnostic delay in axSpA is still unacceptably long. Patients who are female, young at symptom onset, HLA-B27 negative or have psoriasis have a longer diagnostic delay. Specific referral strategies might be necessary in order to decrease the diagnostic delay in patients presenting with these characteristics.

Keywords: axial spondyloarthritis; diagnostic delay.