title: The overuse of serum ceruloplasmin measurement.
abstract: BACKGROUND
  Wilson disease is rare, found in 3 of 100,000 people (0.03%). Ceruloplasmin is often ordered to evaluate liver enzyme elevations. Because Wilson disease often presents before middle-age, the American Association for the Study of Liver Disease recommends screening patients between the ages of 3 and 55 years with liver abnormalities of uncertain cause. We evaluate guideline adherence and the clinical and economic impact of current clinical use of ceruloplasmin.
  
  
  METHODS
  We reviewed all ceruloplasmin measurements at a clinical laboratory that serves a large primary care network, specialty clinics, and a 600-bed tertiary referral center between January 1, 2003, and December 12, 2011.
  
  
  RESULTS
  Ceruloplasmin was measured 5325 times in 5023 unique patients, resulting in 8 (0.16%) new Wilson disease diagnoses. Ceruloplasmin's positive predictive value was 8.4% (95% confidence interval, 7.7-9.3) and false-positive rate was 98.1% (95% confidence interval, 96.2-99.1). A total of 1109 ceruloplasmin levels (20.8%) were ordered in the 1066 patients aged more than 55 years (none with Wilson disease). A "shotgun" approach to liver disease diagnosis was found: Ceruloplasmin was ordered on the same day as hepatitis B (81.0%), hepatitis C (76.0%), autoimmune hepatitis (75.1%), and hemochromatosis (73.1%). Of 424 positive ceruloplasmin results, 91% were not pursued further.
  
  
  CONCLUSIONS
  Guideline adherence restricts ceruloplasmin use to a population with a higher pre-test probability of Wilson disease: patients with chronic liver disease aged 3 to 55 years who have been tested for common causes of liver disease. The majority of the serum ceruloplasmin was measured in patients not indicated by the guidelines, resulting in poor test performance and wasted healthcare resources. Our data on ceruloplasmin use could serve as a touchstone for broader discussions on rational clinical decision making.
authors: Division of Gastroenterology, Beth Israel Deaconess Medical Center, Boston, Mass. Electronic address: e.etapper@bidmc.harvard.edu.
authors: Elliot B
authors: EB
authors: Tapper
authors: David O
authors: DO
authors: Rahni
authors: Ramy
authors: R
authors: Arnaout
authors: Michelle
authors: M
authors: Lai
mesh_terms: D000367:Age Factors; D002570:Ceruloplasmin / Q000032:analysis*; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006527:Hepatolenticular Degeneration / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology; D006801:Humans; D008107:Liver Diseases / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology; D008111:Liver Function Tests / Q000706:statistics & numerical data*; D008297:Male; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D012189:Retrospective Studies
chemical_list: D002570:Ceruloplasmin
keywords: Guidelines; Hepatitis; Liver disease; Wilson disease