Prevalence of axial spondyloarthritis among military draft-eligible populations in South Korea: national and regional trends over recent decades.

Abstract

Introduction: Axial spondyloarthritis (axSpA) is a chronic inflammatory disorder characterised by inflammation of the axial manifestations. For the military draftees, there are no epidemiological data on axSpA in nationwide and population-based databases. This retrospective, nationwide and population-based study aimed to assess the national and regional trends in axSpA prevalence among draft-eligible military populations in South Korea between 2014 and 2023.

Methods: The study included 3 063 805 males examined by the Regional Military Manpower Administration. The annual nationwide prevalence was presented as the prevalence per 10 000 and a 95% CIs. The severity of axSpA was assessed using radiographic scoring of the sacroiliac joint based on the New York criteria. Regional trends of axSpA were evaluated for Seoul, metropolitan areas and provinces, categorised according to transportation accessibility.

Results: The nationwide prevalence of axSpA increased from 10.75 (95% CI 9.68 to 11.81) in 2014 to 21.18 (95% CI 19.37 to 23.00). The prevalence of radiographic axSpA (r-axSpA) followed a similar upward trend, whereas the prevalence of non-radiographic axSpA (nr-axSpA) remained stable. The prevalence of r-axSpA (52.73% in 2015 and 79.52% in 2019) was higher than that of nr-axSpA. Meanwhile, r-axSpA patients with grade 3 sacroiliitis showed the highest prevalence during the recent 3-year follow-up. The mean regional prevalence of nr-axSpA differed significantly among the three regions (p=0.013), whereas there were no differences in the prevalence of r-axSpA (p=0.084).

Conclusions: This epidemiological study revealed an increasing trend in the nationwide prevalence of axSpA over the past decade, primarily driven by an increase in moderate-grade r-axSpA. Therefore, early recognition and awareness of axSpA in young males are essential for initiating appropriate treatment options to slow disease progression.