Background The delay of diagnosis after symptom onset for various subgroups of spondyloarthritis (SpA) is considerable. Increasing focus on this over the last decades may have decreased this delay (1-2).

Objectives To study the duration between symptom onset and date of diagnosis of SpA and its subgroups: ankylosing spondylitis (AS), psoriatic arthritis (PsA), and unspecified spondyloarthritis (USpA). A special focus was to study the change over the past decade.

Methods The Swedish SpAScania cohort (N=5,771, = all patients diagnosed with SpA between 2003 and 2007 in primary or secondary care in the Skåne region, total n=1.3 million 2013) was used. We analyzed patients (n=952) identified as having AS (n=173), PsA (n=579) or USpA (n=200) by a rheumatologist or internist at least one time or by any other physician twice during 2003 to 2007 responding to a postal survey in 2009 and 2011. The survey included questions on years for start of symptoms and diagnosis. All patients included had a self-reported diagnosis of SpA between 1997 and 2007 in the survey 2009. The information from 2009 was used to calculate the duration between symptom onset and date of diagnosis and the response from the 2011 survey to investigate the reliability of these answers (647 patients responded to the survey in both 2009 and 2011 and were hence eligible for reliability analysis). The mean duration (years) was calculated (95% CI), both unadjusted and adjusted for sex, age and year of diagnosis.

Results The overall mean duration between symptom onset and date of a SpA diagnosis was 6.8 years (95% CI: 6.3-7.3), without any obvious secular change up through 2007. The mean duration for AS was 9.0 (95% CI: 7.8-10.3), for PsA 6.0 (5.4-6.6) and USpA 7.2 (95% CI: 6.1-8.3). There was an overall good consistency between the self-assessed year of symptom start, measured in 2009 and in 2011 (ρ=0.58). However, there was a variation between subgroups, consistency being higher in AS (ρ =0.84) and lower in PsA (ρ =0.53).

Conclusions The duration between symptom onset and diagnosis was longest for AS and shortest for PsA with USpA in between. Up to 2007 there was no significant trend for any decrease in such delay for any of the subgroups.

References

1. Sorensen J, Hetland ML. Duration of symptoms before diagnosis in patients with rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis. Ann Rheum Dis 2013;72(Suppl3):80.

2. Salvadorini G, Bandinelli F, DelleSedie A, Riente L, Candelieri A, Generini S. Ankylosing spondylitis: how diagnostic and therapeutic delay have changed over the last six decades. Clin Exp Rheumatol. 2012 Jul-Aug;30(4):561-5.

Disclosure of Interest None declared