Sex ratio in ankylosing spondylitis.
D005260:Female; D006801:Humans; D007493:Iraq / Q000453:epidemiology; D007557:Israel / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012744:Sex Ratio; D013167:Spondylitis, Ankylosing / Q000453:epidemiology*