Nationwide epidemiological survey of chronic pancreatitis in Japan

The aim of this study was to estimate the number of patients treated for ch ronic pancreatitis in 1993 in Japan and to explore the clinico-epidemiologi cal features of chronic pancreatitis. Two surveys were conducted. Stratifie d random sampling was used to select departments in which patients with chr onic pancreatitis were treated, and two different questionnaires were admin istered to obtain relevant information. From the first survey, the total nu mber of patients treated for chronic pancreatitis in Japan in the year 1994 was estimated as 32 000 (95 % confidence interval, 25 000-39 000). Clinico -epidemiological features, based on the 2523 patients reported from the sec ond survey, were subsequently clarified. The sex ratio (male/ female) of th e patients was 3.5. Alcoholic pancreatitis was the most common type in male s (68.5%), and idiopathic pancreatitis in females (69.6%). Compared with th e findings in the last survey in 1985, the proportion of patients with alco holic pancreatitis has decreased slightly from 58.7% to 55.5%, while that o f idiopathic chronic pancreatitis has increased in both males and females. Patients diagnosed by advanced techniques such as computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) accounted for 68. 1% of the total. The number of patients with chronic pancreatitis treated i n 1994 in Japan, was estimated as 32 000, with an overall prevalence rate o f 45.4 per 100 000 population in males and 12.4 per 100 000 population in f emales.