Diagnostic delay in axial spondyloarthritis: A cross-sectional study of 432 patients

The diagnostic delay of axial spondyloarthritis (axSpA) is usually reported to be more than seven years but may have decreased recently. The objective was to quantify the diagnostic delay in patients with axSpA in France and to explore its associated factors.

Two cross-sectional observational studies included consecutively patients with axSpA (according to both ASAS criteria and rheumatologist expert opinion). Diagnostic delay was defined as the time interval from the date of first symptoms to the date of diagnosis. Potential predictive factors of diagnostic delay analyzed by multiple linear regression were demographic factors, HLA B27 status, year of diagnosis, clinical presentation and sacroiliitis on MRI or radiography.

In all, 432 patients were analyzed: the mean age at diagnosis was 34.2 (standard deviation, 12.5) years, the mean disease duration at the time of the assessment was 11.4 (10.4) years. In all, 66.7% were HLA B27 positive, and 70.2% had radiographic sacroiliitis. The mean diagnostic delay was 4.9 (6.3) years, with a median of 2.0 years (interquartile range, 1-7; range: 0-43). In multivariable analysis, factors independently associated with a longer diagnostic delay were: higher age at diagnosis (beta=0.13; P<0.001), less frequent peripheral arthritis or dactylitis (beta=-1.69; P=0.005), and more frequent entheseal pain (beta=1.46; P=0.015).

The median diagnostic delay was 2 years indicating diagnostic delay may be for most patients shorter than previously reported. A more "typical" SpA clinical presentation was associated with a shorter diagnostic delay, whereas sacroiliitis and HLA B27 positivity were not associated with this delay.