title: The prevalence, incidence and natural history of primary sclerosing cholangitis in an ethnically diverse population.
abstract: BACKGROUND
  Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic liver disease often associated with inflammatory bowel diseases (IBD). Current epidemiological data are limited to studies of predominantly Caucasian populations. Our aim was to define the epidemiology of PSC in a large, ethnically diverse US population.
  
  
  METHODS
  The Northern California Kaiser Permanente (KP) database includes records from over 3 million people and was searched for cases of PSC between January 2000 and October 2006. All identified charts were reviewed for diagnosis confirmation, IBD co-morbidity, and major natural history endpoints.
  
  
  RESULTS
  We identified 169 (101 males) cases fulfilling PSC diagnostic criteria with a mean age at diagnosis of 44 years (range 11-81). The age-adjusted point prevalence was 4.15 per 100,000 on December 31, 2005. The age-adjusted incidence per 100,000 person-years was not significantly greater in men 0.45 (95% CI 0.33-0.61) than women 0.37 (95% CI 0.26-0.51). IBD was present in 109/169 (64.5%) cases and was significantly more frequent in men than women with PSC (73.3% and 51.5%, respectively, p = 0.005). The cumulative average yearly mortality rate was 1.9%. Age and serum sodium, creatinine and bilirubin at diagnosis and albumin at last entry were identified as significant factors associated with death, liver transplant or cholangiocarcinoma.
  
  
  CONCLUSIONS
  The incidence and prevalence of PSC observed in a representative Northern California population are lower compared to previous studies in Caucasian populations and this might reflect differences in the incidence of PSC among various ethnic groups.
authors.affiliation: Department of Medicine, University of California Davis Medical Center, Sacramento, CA, USA.
authors.forename: Elaine
authors.initials: E
authors.lastname: Toy
authors.forename: Sripriya
authors.initials: S
authors.lastname: Balasubramanian
authors.forename: Carlo
authors.initials: C
authors.lastname: Selmi
authors.forename: Chin-Shang
authors.initials: CS
authors.lastname: Li
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Bowlus
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002140:California / Q000453:epidemiology; D002648:Child; D015209:Cholangitis, Sclerosing / Q000208:ethnology* / Q000401:mortality / Q000473:pathology; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D055815:Young Adult