[Study on the associated risk factors of rheumatic pain: a ILAR-China, WHO COPCORD Shantou study].

OBJECTIVE: To validate the difference on the prevalence of rheumatic symptoms between north and south parts of the country and to study the associated risk factors of rheumatic complaints in Shantou city, China. METHODS: A total number of 10 638 people at above 16 years of age from four samples, were surveyed in 1987, 1992, 1995, and 1999. Protocol of International League Against Rheumatism (ILAR)-China collaborative study or WHO-ILAR community oriented program for control of rheumatic disease(COPCORD) core questionnaire was implemented. Data on related rheumatic symptoms were collected and analyzed. RESULTS: The prevalence rate of rheumatic complaints had been increasing in Shantou area during the last decade (in 1987 11.6%, 1992 12.5%, 1995 16.0% and 1999 19.8%) but still lower than that seen in Beijing, China in 1987(40.0%). Rheumatic symptoms were more prevalent in females than in males, in elderly than in young people with most frequently involved site happened in low back area, followed by knee and neck. Lumbar pain was more frequent among rural residents, while neck pain was more prevalent in urban school students. Prevalence of knee pain was significantly higher in people living in multi-storey buildings without elevator than those living in single-storey houses. The peak values of Bone Mineral Density in Shantou population were (0.839 +/- 0.085) g/cm2 in men, and (0.723 +/- 0.064) g/cm2 in women, significantly higher than that reported in 13 other provinces and cities including Beijing. The sense of seeking for medical help was higher in population with higher prevalence of rheumatic symptoms than that in lower complaints group. However, no significant difference was found in the rates of disability among the different populations. CONCLUSION: The prevalence rate of rheumatic complaints was lower in Shantou than that in Beijing. Socio-economic status, environment, sex, age, occupation, ergonomics, bone mineral density, and awareness of seeking medical care might have been the associated risk factors to the prevalence of rheumatic complaints.

Low prevalence of knee and back pain in southeast China; the Shantou COPCORD study.

OBJECTIVE: To determine whether the previously noted low prevalence of knee pain (KP) and lumbar pain (LP) in rural southern China compared with the high prevalence observed in North China was also true in a southern urban population. METHODS: A population based sample of 2040 adults > or = 16 years of age was studied in Chenghai City, close to the rural area previously studied on the southeast coast of China. Primary healthcare workers administered the COPCORD Phase I and II questionnaires. Those with rheumatic symptoms were recalled for medical examination, with a response rate at examination (phase III) of 98.4%. Those suspected of having arthritis had radiographs and laboratory tests. Prevalences were age and sex adjusted to the total of populations previously reported. RESULTS: (1) The prevalence for all rheumatic symptoms at phase III was 18.1%. Of the 7.5% with KP, 55% had osteoarthritic changes on radiograph (KOA) compared with 29% of a sample with no KP (p < 0.001). Of the 11.5% with LP, 69% had degenerative changes on lumbar spine radiograph (LOA). (2) Of residents in single-level houses the prevalence was 5.6% for KP and 7.9% for LP, whereas in 4 to 6-level apartment buildings these rates were significantly higher, 9.1% and 16.2%, respectively. All these pain rates were significantly lower than noted in rural North China. The prevalence of pain together with radiographic OA changes in the knee (KOA) was half the rate in single-floor residents (2.7%) compared to apartment residents (5.3%), as was lumbar spine degenerative disease (5.3% vs 11.5%). CONCLUSION: The prevalence of knee and lumbar spine pain in this southern urban sample was confirmed to be much lower than in the rural sample in the North, although higher than in the rural sample in the South. Comparing COPCORD studies of Han Chinese in Shanghai and Malaysia there was a decrease in prevalence of knee and back pain with latitude, suggesting an association with climate. Knee and back pain and radiological degenerative changes in the knee and lumbar spine were twice as prevalent in apartment residents than in those living in older single-level houses. Further study is needed to explain these observations.