Table 1. Examples of CDS malfunctions categorized by Wright's CDS malfunction taxonomy 8 .

CDS examples	Type of monitoring	Cause	Mode of discovery	Initiation	Effect on rule firing
1A. CDS that reminds providers to add a principal problem to the problem list	Preactivation	Conceptualization error	Review of firing data	From its implementation in production	Rule fires in situations where it should not fire
1B: CDS that reminds providers to add a principal problem to the problem list	Postactivation	Conceptualization error	Review of firing data	After deployment into production	Rule fires in situations where it should not fire
2. CDS that recommends an EKG when a patient is on two or more QTc prolonging medications	Preactivation	Build error	Review of firing data	From its implementation in production	Rule fires in situations where it should not fire
3. CDS that informs nurses when a medication dose is given too close to a previous dose as documented on the medication administration record (MAR)	Ad hoc	Conceptualization error	Reported by an end user	After deployment into production	Rule does not fire in situations where it should
4. CDS which reminds providers to order venous thromboembolism (VTE) prophylaxis within 4 h of admission	Ad hoc	1. New code, concept or term introduced, but rule not updated 2. Defect in EHR software	1. Reported by an end user 2. Review of firing data	After deployment into production	Rule fires in situations where it should not fire
5. CDS that provides guidance for ordering radiology procedures via a web service call to a third-party vendor	Continuous automated	External service issue	Review of firing data (automatic process)	After deployment into production	Rule does not fire in situations where it should

Abbreviations: CDS, clinical decision support; EHR, electronic health record; EKG, electrocardiogram.