The prevalence of spondyloarthritis (SpA) and its prototype ankylosing spondylitis (AS) varies considerably in different parts of the world. With 20% of the world's population in China, there is potential for a significant disease burden. Eight of the 10 articles providing primary data on the prevalence of SpA in China are in the Chinese language; our objective is to review all 10 articles for English readers.
Articles were retrieved by search engines in both the English language (www.pubmed.gov) and Chinese language web sites (www.cnki.net). We limited our search to publications of the period 1994 to 2006, and the key words used were (entered as Chinese characters) "prevalence AND spondyloarthropathy," "prevalence AND ankylosing spondylitis," "epidemiology AND spondyloarthropathy," and "epidemiology AND ankylosing spondylitis." For each survey, we examined the number of subjects surveyed, the survey instrument, the criteria used for classifying patients as SpA or AS, and other methodological quality issues.
There were 2 AS surveys in the military and 8 surveys in the civilian communities. Overall, the pooled prevalence of AS for the military and civilian communities is 0.24%, 95% confidence interval (CI: 0.17 to 0.32) and 0.23%, 95% CI (0.19 to 0.28), respectively. There is 1 SpA survey in the military and 4 surveys in the civilian communities. The prevalence of SpA in the military survey is 0.45%. The pooled prevalence of SpA from the civilian surveys is 0.93%, 95%CI (0.53 to 1.65). We found that the survey methodology is generally not well reported, giving rise to concerns about the methodological quality and hence validity of the results.
The prevalence of AS and SpA in China are similar to Caucasians in the U.S. or Europe.