Clinical and Laboratory Standards Institute guideline EP12—Evaluation of Qualitative, Binary Output Examination Performance describes the categories of qualitative, binary output examinations and covers their performance evaluations for imprecision, including estimating C5 and C95, clinical performance (sensitivity and specificity), and stability and interferences.

This guideline replaces the previous edition of the approved guideline, EP12-A2, published in 2008. Several changes were made in this edition, including: 

• Expanding the types of procedures covered to reflect ongoing advances in laboratory medicine 

• Adding protocols to be used by developers, including commercial manufacturers or medical laboratories, during examination procedure design as well as for validation and verification 

• Adding topics such as stability and interferences to the existing coverage of the assessment of precision and clinical performance (or examination agreement) 

• Moving most of the statistical details, including equations, to the appendixes

EP12 provides product design guidance and protocols for performance evaluation of the Establishment and Implementation Stages of the Test Life Phases Model of examinations (see CLSI document EP19). EP12 characterizes a target condition (TC) with only two possible outputs (eg, positive or negative, present or absent, reactive or nonreactive). EP12 is written for both manufacturers of qualitative, binary, results-reporting or output examinations (referred to as qualitative, binary examinations throughout) and medical laboratories that create laboratory-developed, binary examinations (both termed developers). These protocols are also intended to help users verify examination performance in their own testing environment. Performance evaluation of examinations that provide outputs with more than two possible categories in an unordered (nominal) set or that report ordinal categories are outside the scope of this guideline.