title: Prevalence and Natural History of Microscopic Colitis: A Population-Based Study With Long-term Clinical Follow-up in Terrassa, Spain.
abstract: OBJECTIVE
  Few studies have assessed the prevalence of microscopic colitis (MC) and the natural history of this disease is not well known. The aim of this study was to evaluate the prevalence rate of MC, the burden of disease in terms of loss of health and the long-term natural history of MC in a population-based cohort study.
  
  
  METHODS
  Cases were obtained from the pathology department registry Hospital Universitari Mutua Terrassa. Belonging to the catchment area, maintaining residence in that area, and being alive on August 31, 2014 were confirmed for each case. Adjusted prevalence rates were calculated. Current active drugs for MC and diarrhoea persistence in every patient were recorded.
  
  
  RESULTS
  The prevalence rate of MC was 107 per 10(5) inhabitants. The rate of patients with active disease, i.e. those representing the true burden of the disease in terms of loss of health, was 31 per 10(5) inhabitants. After a follow-up of 7.8±0.38 years from diagnosis, 75% of the patients experienced prolonged disease remission, defined as clinical remission without requiring drugs for 1 year or more. The only variable associated with prolonged MC remission was how clinical remission was achieved (spontaneous 93.3%, drug-induced, 60.5%; odds ratio 8.4, 95% confidence interval 2.7-26).
  
  
  CONCLUSIONS
  The rate of patients with MC and active disease, which represents the true disease burden in terms of loss of health, is low. Most patients with MC experience prolonged disease remission, with key differences between spontaneous and drug-induced clinical remission.
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Terrassa, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Terrassa, Spain ffbanares@mutuaterrassa.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Fernández-Bañares
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Terrassa, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Terrassa, Spain.
authors.forename: Yamile
authors.initials: Y
authors.lastname: Zabana
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Terrassa, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Terrassa, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Aceituno
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Terrassa, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Terrassa, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Ruiz
authors.affiliation: Department of Pathology, Hospital Universitari Mutua Terrassa, Terrassa, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Terrassa, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Salas
authors.affiliation: Department of Gastroenterology, Hospital Universitari Mutua Terrassa, Terrassa, Spain Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Terrassa, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Esteve
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D046728:Colitis, Microscopic / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D017281:Cost of Illness; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D012189:Retrospective Studies; D013030:Spain / Q000453:epidemiology; D055815:Young Adult
keywords: Collagenous colitis; lymphocytic colitis; natural history; prevalence rate