title: Nationwide epidemiological survey of early chronic pancreatitis in Japan.
abstract: BACKGROUND
  The world's first diagnostic criteria for early CP were proposed in 2009 in Japan. This study aimed to clarify the clinico-epidemiological features of early CP in Japan.
  
  
  METHODS
  Patients with early CP who were diagnosed according to the diagnostic criteria for early CP and had visited the selected hospitals in 2011 were surveyed. The study consisted of two-stage surveys: the number of patients with early CP was estimated by the first questionnaire and their clinical features were assessed by the second questionnaire.
  
  
  RESULTS
  The estimated number of early CP patients was 5410 (95% confidence interval 3675-6945), with an overall prevalence of 4.2 per 100,000 persons. The number of patients who were newly diagnosed with early CP was estimated to be 1330 (95% confidence interval 1058-1602), with an annual incidence of 1.0 per 100,000 persons. Detailed clinical information was obtained in 151 patients in the second survey. The male-to-female sex ratio was 1.32:1. The mean age was 60.4 and the mean age at disease onset was 55.4. Idiopathic (47.7%) and alcoholic (45.0%) were the two most common etiologies. Proportions of female and idiopathic cases were higher in early CP than in definite CP. Hyperechoic foci without shadowing and stranding were the most common findings on endoscopic ultrasonography. The clinical profiles of early CP patients who showed lobularity with honeycombing on endoscopic ultrasonography or previous episodes of acute pancreatitis were similar to those of definite CP patients.
  
  
  CONCLUSIONS
  We clarified the current status of early CP in Japan.
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. amasamune@med.tohoku.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Masamune
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuta
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Tatsuhide
authors.initials: T
authors.lastname: Nabeshima
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Nakano
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Morihisa
authors.initials: M
authors.lastname: Hirota
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kanno
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kume
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Hamada
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Tetsuhide
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Gastroenterology, Toyohashi Municipal Hospital, Toyohashi, Japan.
authors.forename: Motokazu
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Department of Gastroenterology, Aizu Medical Center, Fukushima Medical University, Aizu-Wakamatsu, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Irisawa
authors.affiliation: Department of Gastroenterology, Gifu Municipal Hospital, Toyohashi, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakashima
authors.affiliation: Department of Gastroenterology, JA Onomichi General Hospital, Onomichi, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Hanada
authors.affiliation: Department of Gastroenterology and Hepatology, Osaka Saiseikai Nakatsu Hospital, Osaka, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Eguchi
authors.affiliation: Department of Molecular Gastroenterology and Hepatology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Kato
authors.affiliation: Department of Medicine, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Inatomi
authors.affiliation: Shirane Gastrointestinal Clinic, Sendai, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Shirane
authors.affiliation: Department of Surgery, Faculty of Medicine, Kindai University, Osaka, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Takeyama
authors.affiliation: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuji
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000437:Alcoholism / Q000150:complications; D002760:Cholangiopancreatography, Endoscopic Retrograde; D019160:Endosonography; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D050500:Pancreatitis, Chronic / Q000175:diagnosis* / Q000201:enzymology / Q000453:epidemiology* / Q000209:etiology; D010641:Phenotype; D015995:Prevalence; D011795:Surveys and Questionnaires
keywords: Alcohol; Diagnosis; Endoscopic ultrasonography; Epidemiology; Functional dyspepsia