A scheme for the evaluation of methods in clinical chemistry with particular application to those measuring enzyme activities. Part I: general considerations.

A 20-point system is presented whereby commercially produced clinical chemistry procedures, i.e., in vitro diagnostic kits, may be assessed for adequacy of packaging, labelling and enclosed literature. Criteria are given for the selection of a reference method to use in the test method evaluation and the design of a patient comparison study using these two methods is described. The importance of standards and calibration materials as they relate to accuracy and specificity is discussed. A procedure for assessing accuracy by recovery studies is outlined. A method for the assessment of precision on a within-day and a day-to-day basis is described.