Epidemiological survey on prevalence of ankylosing spondylitis in 5 922 Shenzhen inhabitants

Zhizhong YE; Junhan ZHUANG; Xun WANG; Jiansong LI; Lijun ZHANG

ABSTRACT

BACKGROUND:

The data of epidemiological survey on rheumatic diseases such as ankylosing spondylitis (AS) are very rare in China, especially in Shenzhen. The comprehensive understanding of epidemiological situation of AS in Shenzhen can be used to draw up treatment plans by Shenzhen Health Bureau and some other health organizations.

OBJECTIVE:

To investigate the epidemiological features of AS.

DESIGN:

Randomized complete collection and cross-sectional investigation.

SETTING:

Shenzhen Rheumatism Institute of Guangdong Medical College.

PARTICIPANTS:

From December 2001 to April 2004, totally 6 684 adults aged over 16 years were selected from three regions (one region of river and lakes, one local mountain region and one inhabitant region) of Shenzhen. Among them, 5 922 adults (2 659 males and 3 263 female) were actually investigated and the investigative rate was 88.6%. Males were accounted for 44.9% and females were 55.1%, and the ratio was 11.23.

METHODS:

Step 1 and 2, the investigated individuals were questioned and their answers were recorded by the investigators. The questionnaire proceeded one by one for every individual and proceeded at homes. Step 3,the individuals with positive findings at steps 1 and 2 were examined by rheumatologic doctors. Step 4, individuals with suspected AS were subjected to human leukocyte antigen B27 (HLA-B27) assays, radiographies including plain pelvic films, plain lumbar-vertebral films and if necessary, radiographies at other areas of spinal column as well as peripheral joints.MAIN OUTCOME

MEASURES:

Frequencies of rheumatic complaints,prevalence rate of AS, positive frequencies of hum an HLA-B27, and comparisons with relevant data abroad.

RESULTS:

① General frequency of rheumatism was 21.6%, and the highest complaint was at knee joint, then at waist, shoulder, neck and hand. In female, the frequencies of complaints at every joint mentioned above were higher than those in male (P ＜ 0.05). A total of 13 patients (4.7%) had to discontinue their work because of rheumatic diseases. ②Prevalence rate of AS was accounted for 0.37%, and the ratio between male and female was 4.5 1. The onset of AS began at middle age in majority patients. ③ Positive frequency of HLA-B27 was 5.0%. ④ Rate of misdiagnosis, the rate of early diagnosis and the rate of long-term irrational drug-usage were 64%, 27% and 73%, respectively.

CONCLUSION:

In Shenzhen, the prevalence rate of AS (0.37%) is ranked higher than that in Beijing (0.26%), Shantou (0.26%), America(0.20%) and the whites of Greece (0.24%). The differences among them may be connected with the fact that in Shenzhen the young people occupy a large proportion of population.