title: Emerging Epidemic of Inflammatory Bowel Disease in a Middle Income Country: A Nation-wide Study from Iran.
abstract: BACKGROUND
  The burden of inflammatory bowel disease (IBD) hasn't been reported in Iran. We aimed to estimate the prevalence and incidence of IBD and its trend in Iran at national and subnational level from 1990 to 2012.
  
  
  METHODS
  We conducted a systematic review of English and Persian databases about the epidemiology of IBD. We also collected outpatient data from 17 provinces of Iran using almost all public and private referral gastroenterology clinics. Prevalence and incidence rate was calculated at national and subnational levels. The Kriging method was used to extrapolate provinces with missing data and GPR model to calculate time trends of rates at subnational level.
  
  
  RESULTS
  We found 16 case series, two population-based studies, and two review articles. We collected 11,000 IBD cases from outpatient databases. Among them, 9,269 (84.26%) had ulcerative colitis (UC), 1,646 (14.96%) had Crohn's disease (CD), and 85 had intermediate colitis (IC). A total of 5,452 (49.56%) patients were male. Mean age at diagnosis was 32.80 years (CI: 13 - 61) for UC and 29.98 years (CI: 11 - 58) for CD. Annual incidences of IBD, UC, and CD in 2012 were 3.11, 2.70, and 0.41 per 100,000 subjects respectively. Prevalence of IBD, UC, and CD in 2012 were 40.67, 35.52, and 5.03 per 100,000 subjects respectively. The incidence of UC and CD showed a significant increase during the study period (P for trend < 0.05).
  
  
  CONCLUSIONS
  The incidence and prevalence of IBD are increasing in Iran. Establishing a national IBD registry seems necessary for comprehensive care of IBD patients in Iran.
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Masoud M
authors.initials: MM
authors.lastname: Malekzadeh
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Homayoon
authors.initials: H
authors.lastname: Vahedi
authors.affiliation: Department of Biostatistics, Faculty of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran, Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kimiya
authors.initials: K
authors.lastname: Gohari
authors.affiliation: Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran, Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Parinaz
authors.initials: P
authors.lastname: Mehdipour
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sadaf G
authors.initials: SG
authors.lastname: Sepanlou
authors.affiliation: Department of Gastroenterology, Imam Khomeini Hospital Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nasser
authors.initials: N
authors.lastname: Ebrahimi Daryani
authors.affiliation: Gastrointestinal and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Zali
authors.affiliation: Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences (GUMS), Rasht, Iran.
authors.forename: Fariborz
authors.initials: F
authors.lastname: Mansour-Ghanaei
authors.affiliation: Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Safaripour
authors.affiliation: Gastrointestinal and Liver Diseases Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Rahim
authors.initials: R
authors.lastname: Aghazadeh
authors.affiliation: Department of Gastroenterology and Hepatology, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Vossoughinia
authors.affiliation: Gut and Liver Research Center, Mazandaran University of Medical Sciences, Sari, Iran.
authors.forename: Hafez
authors.initials: H
authors.lastname: Fakheri
authors.affiliation: Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Somi
authors.affiliation: Gut and Liver Research Center, Mazandaran University of Medical Sciences, Sari, Iran.
authors.forename: Iradj
authors.initials: I
authors.lastname: Maleki
authors.affiliation: Gut and Liver Research Center, Mazandaran University of Medical Sciences, Sari, Iran.
authors.forename: Vahid
authors.initials: V
authors.lastname: Hoseini
authors.affiliation: Department of Gastroenterology, Shahid Beheshti Hospital, Qom University of Medical Sciences, Qom, Iran.
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Ghadir
authors.affiliation: Gastroenterology Section, Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Daghaghzadeh
authors.affiliation: Gastroenterology Section, Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Payman
authors.initials: P
authors.lastname: Adibi
authors.affiliation: Gastroenterology Section, Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Tavakoli
authors.affiliation: Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Taghavi
authors.affiliation: Digestive Research Center, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Mohammad-Javad
authors.initials: MJ
authors.lastname: Zahedi
authors.affiliation: Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Taghi
authors.initials: T
authors.lastname: Amiriani
authors.affiliation: Department of Internal Medicine, Bushehr University of Medical Science, Bushehr, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Tabib
authors.affiliation: Department of Internal Medicine, Bushehr University of Medical Science, Bushehr, Iran.
authors.forename: Zainab
authors.initials: Z
authors.lastname: Alipour
authors.affiliation: Department of Internal Medicine, Semnan University of Medical Science, Semnan, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Nobakht
authors.affiliation: Department of Medicine, Ardabil University of Medical Science, Ardabil, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Yazdanbod
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Sadreddini
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Bakhshipour
authors.affiliation: Department of Gastroenterology and Hepatology, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Khosravi
authors.affiliation: Department of Medicine, Dezful University of Medical Science, Dezful, Iran.
authors.forename: Pejman
authors.initials: P
authors.lastname: Khosravi
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Siavosh
authors.initials: S
authors.lastname: Nasseri-Moghaddam
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Shahin
authors.initials: S
authors.lastname: Merat
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Rasoul
authors.initials: R
authors.lastname: Sotoudehmanesh
authors.affiliation: Department of Internal Medicine, North Khorasan University of Medical Sciences, Bojnourd, North Khorasan, Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Barazandeh
authors.affiliation: Department of Gastroenterology and Hepatology, Afzalipour Hospital, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Peyman
authors.initials: P
authors.lastname: Arab
authors.affiliation: Department of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Nadieh
authors.initials: N
authors.lastname: Baniasadi
authors.affiliation: Department of Medicine, Dezful University of Medical Science, Dezful, Iran.
authors.forename: Seyyed-Javad
authors.initials: SJ
authors.lastname: Pournaghi
authors.affiliation: Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran, Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahboubeh
authors.initials: M
authors.lastname: Parsaeian
authors.affiliation: Non-Communicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran, Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Farshad
authors.initials: F
authors.lastname: Farzadfar
authors.affiliation: Digestive Disease Research Center, Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. malek@tums.ac.ir.
authors.forename: Reza
authors.initials: R
authors.lastname: Malekzadeh
mesh_terms: D003093:Colitis, Ulcerative / Q000453:epidemiology*; D003424:Crohn Disease / Q000453:epidemiology*; D016208:Databases, Factual; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D012042:Registries; D012307:Risk Factors; D012959:Socioeconomic Factors