title: Unnecessary repeated total cholesterol tests in biochemistry laboratory.
abstract: BACKGROUND
  We aimed to determine the number of repeated cholesterol (RC) tests and the ratio of unnecessary-repeated cholesterol (URC) tests among patients admitted to Pamukkale University Hospital (Denizli, Turkey) and provide solutions to avoid URC testing.
  
  
  METHODS
  Total cholesterol (T-cholesterol) tests (N = 86,817) between June 2014 and May 2015 were evaluated. The tests performed more than once per patient were determined as RC test (N = 28,811). RC test with an interval shorter than 4 weeks were determined as URC test (N = 3968) according to the shortest retest interval stated in ACC/AHA blood cholesterol guideline. RC testing included internal medicine, surgery and paediatric outpatients and inpatients. Reference change value (RCV) of total cholesterol was calculated.
  
  
  RESULTS
  The 33.1% of the T-cholesterol tests were RC tests (N = 28,811), 13.7% of them were URC tests (N = 3968). Our RCV value was 25%. The percentage change between consecutive tests was less than RCV in 86.1% (N = 3418) of URC tests. URC tests were performed more frequently in patients with desirable total cholesterol value (P < 0.001).
  
  
  CONCLUSIONS
  There is a significant part of repeated T-cholesterol tests requested in our hospital. URC test requests can be evaluated by laboratories and the obtained data should be shared with clinicians. Laboratories can calculate RCV for the tests they performed and report this value with the test result. To prevent from URC tests, a warning plug-in can be added to hospital information software in accordance with guidelines to prevent from URC test requests.
authors.affiliation: Pamukkale University, Faculty of Medicine, Department of Medical Biochemistry, Denizli, Turkey.
authors.forename: Suleyman
authors.initials: S
authors.lastname: Demir
authors.affiliation: Pamukkale University, Faculty of Medicine, Department of Medical Biochemistry, Denizli, Turkey.
authors.forename: Nergiz
authors.initials: N
authors.lastname: Zorbozan
authors.affiliation: Pamukkale University, Faculty of Medicine, Department of Medical Biochemistry, Denizli, Turkey.
authors.forename: Elif
authors.initials: E
authors.lastname: Basak
mesh_terms: D002784:Cholesterol / Q000097:blood*; D019963:Clinical Chemistry Tests / Q000379:methods / Q000592:standards*; D017408:Guidelines as Topic; D006785:Hospitals, University; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data; D007755:Laboratories, Hospital / Q000592:standards*; D010045:Outpatients / Q000706:statistics & numerical data; D011786:Quality Control; D012016:Reference Values; D015203:Reproducibility of Results; D012621:Seasons; D013997:Time Factors
chemical_list: D002784:Cholesterol
keywords: cholesterol retest interval; laboratory costs; preanalytical phase; reference change value; test requesting; unnecessary repeated cholesterol test