Prevalence of axial spondyloarthritis in Colombia: data from the National Health Registry 2017-2021

IntroductionRegistries allow ascertaining the epidemiology of chronic diseases such as axial spondyloarthritis (axSpA). The Colombian Ministry of Health has implemented a National Health Registry (SISPRO) that collects data from each medical contact in the system, which provides close to universal coverage (around 98%).ObjectiveTo establish the 5-year prevalence of axSpA in Colombia, and to describe its demographics, using data from January 1st, 2017, to December 31st, 2021.MethodsWe performed an observational, cross-sectional study using the International Statistical Classification of Diseases and Related Health Problems as search terms related to ax-SpA, based on SISPRO data. We estimated the prevalence using three approaches: (1) ankylosing spondylitis (AS) diagnoses; (2) diagnoses compatible with axSpA; and (3) diagnoses compatible with axSpA, including sacroiliitis. We calculated prevalence per 100,000 inhabitants.ResultsBased on our three approaches, patients with a primary diagnosis compatible with ax-SpA ranged between 12,684 and 117,648, with an estimated 5-year adjusted prevalence between 26.3 and 244 cases per 100,000 inhabitants (0.03-0.2%). The male-to-female ratio ranged between 1.2:1 and 0.4:1, which was markedly skewed towards a higher prevalence in women when we included the code for sacroiliitis. We found the highest frequency of cases in the 50-54 years group. A differential prevalence was observed between different regions in our country, particularly in regions known to have European ancestors.ConclusionThis is the first study that describes demographic characteristics of ax-SpA in Colombia and offers valuable information for stakeholders. Key Points center dot Using the official country-level health database, the prevalence of axSpA in Colombia ranges between 26.3 and 244 cases per 100,000 inhabitants (0.03% - 0.2%)center dot The prevalence of axSpA peaked among the 50-54 years patient group, suggesting an increased survival center dot Nations with a substantial admixture, such as Colombia, may present a differential prevalence of axSpA among regions within the country center dot Including the ICD-10 code for sacroiliitis (M46.1) in epidemiological studies probably overestimates the frequency of axSpA