A study published in Arthritis Care & Research refutes the conventional wisdom regarding ankylosing spondylitis (AS) and suggests that there appears to be no gender gap in the prevalence of the disease. 

Researchers noted that there was no statistically significant difference in the rates between men and women according to an analysis of military medical records. Researchers retrospectively tracked 728,556 members of the U.S. military who had been subjected to guideline-directed screening for back pain during 2014-2017. About 85% of the study population was male. The subjects were assessed for a mean of 2.21 years, and 0.06% were diagnosed with AS at least once during this period. The rates of AS among males vs. females were found to be similar (incidence rate ratio, 1.16; adjusted odds ratio, 0.79; 95% confidence interval, 0.61-1.02; P = .072)… (Medscape)