title: A risk-analysis approach to the evaluation of analytical quality.
abstract: BACKGROUND
  Setting specifications for analytical quality is always difficult. The risk-management approach might be a way to do so. In this approach, the definition of the required analytical quality is based on the evaluation of patient risk. Risk derives from the probability of error and from the damage that such an error might cause.
  
  
  METHODS
  Eight Italian laboratories took part in this experiment. Measurements of glucose and total calcium were taken as examples. Analytical quality was evaluated using a specific ring trial with a frozen serum pool and by means of internal quality-control data. The total allowable error was defined according to biological variation specifications. The probability of error was extracted from the imprecision and comparative bias data of each laboratory. The damage caused by a wrong result was evaluated using the absolute probability judgment approach.
  
  
  RESULTS
  According to the iso-risk plots (standardized hyperboles on a graph where the x-axis represents damage and the y-axis represents probability) for glucose, all the laboratories were working with an analytical quality that guaranteed low risk for patients. On the contrary, for total calcium none of the laboratories exhibited sufficient quality to guarantee low risk for patients, the presence of bias being the most relevant problem.
  
  
  CONCLUSIONS
  The results seem to demonstrate the applicability of the risk approach to the analytical phase, indicating a new possible way to define analytical quality targets.
authors.affiliation: Diagnostica e Ricerca San Raffaele, San Raffaele Scientific Institute, Milan, Italy. ceriotti.ferruccio@hsr.it
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Ceriotti
authors.forename: Piero
authors.initials: P
authors.lastname: Cappelletti
authors.forename: Marco
authors.initials: M
authors.lastname: Caputo
authors.forename: Francesca
authors.initials: F
authors.lastname: Di Serio
authors.forename: Gianni
authors.initials: G
authors.lastname: Messeri
authors.forename: Cosimo
authors.initials: C
authors.lastname: Ottomano
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
authors.forename: Giuliano
authors.initials: G
authors.lastname: Soffiati
mesh_terms: D019963:Clinical Chemistry Tests / Q000592:standards*; D003951:Diagnostic Errors; D006801:Humans; D011786:Quality Control; D018570:Risk Assessment