The prevalence of axial spondyloarthritis (axSpA) or ankylosing spondylitis in a population depends upon the following 1)Ethnic groups 2) Selection of subjects for evaluation and 3) The criteria for diagnosis.It shows a clear evidence that correlation between the prevalence of ankylosing spondylitis (AS)/axial spondyloarthritis (axSpA) in a given population and the prevalence of human leukocyte antigen HLA-B27 exits.

• The prevalence of ankylosing spondylitis is approximately 7-490 per 100,000 individuals worldwide.^[1][2]
• In the year 2009, according to National Health and Nutrition Examination Survey (NHANES) the incidence of ankylosing spondylitis was estimated to be 6.1% cases per 100,000 individuals worldwide.

• The incidence of ankylosing spondylitis is approximately 7.26 per 100,000 persons in the adult population.

• The incidence of fractures in ankylosing spondylitis is approximately  4 to 18 percent .
• The incidence of ankylosing spondylitis is approximately 6–7 per 100,000 persons in caucasian populations.

• The mortality rate of ankylosing spondylitis is approximately was 1.60 (95% CI 1.44-1.77).
• The mortality rate of ankylosing spondylitis increased mostly because of circulatory disease that associated with ankylosing spondylitis.

• The incidence of ankylosing spondylitis increases with age; the median age at diagnosis is second and third decades of life years.
• Mostly 80% of the patients with ankylosing spondylitis(AS) experience symptoms at ≤ 30 years of age, But only 5% will present with symptoms at ≥ 45 years of age.

• Ankylosing spondylitis(AS) usually affects individuals of the North America race. Japan individuals are less likely to develop ankylosing spondylitis(AS).

• Men are more commonly affected by Ankylosing spondylitis(AS) than women. The men to women ratio is approximately 2:1.