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[A comparative study of incidence and prevalence of Crohn's disease in mainland China in different periods].

OBJECTIVE
To collect data and analyze the current status and prevalence changes of Crohn's disease (CD) in mainland China in recent decades.


METHODS
A computer-based literature search was previously performed by using 50-year (1950 to 2002) of records of CD from the Chinese Database of Biology and Medicine (CBM) (1979 to 2002) and a manual year-by-year search of the literature (1950 to 1978). Using similar method, descriptive epidemiological data from 2003 to 2007 were collected, analyzed and compared with previous research.


RESULTS
Four hundred and seventeen relevant papers during 2003 and 2007 were collected and 62 papers were eligible for inclusion. Within 62 papers, a total of 2149 cases with CD from 2003 to 2007 have been reported nationwide, comprising 1288 male and 861 female patients, with a 1.50:1 male predominance, and indicating 1.41 time of increment as compared with our previous result (ie, 1526 cases from 1950 - 2002). There were no obvious changes in incidence age (younger and middle age were main components) and sex ratio (number of male was still larger than that of female). The extrapolated CD incidence and prevalence rates were 1.21/100 000 person·year and 2.29/100 000, respectively, which were higher than that of year 1950 - 2002, 0.28/100 000 person·year and 1.38/100 000, respectively.


CONCLUSIONS
The incidence and prevalence rates of CD have been increasing rapidly, but these rates are still lower than those in Western world.