Noncompliance: The failure or refusal to comply: the failure or refusal to conform and adapt one's actions to a rule or to necessity.

The term "noncompliance" is used in medicine particularly in regard to a patient not taking a prescribed medication or following a prescribed course of therapy. For example, "As many as half of 'failures' of treatment to bring elevated blood pressure down to normal levels may be due to unrecognized lapses in taking antihypertensive drugs as prescribed, according to a new study by a team of researchers from the University of Lausannne, Switzerland." (Stephenson J, JAMA 282: 313, 1999)

Noncompliance may be overt (as with a Christian Scientist who rejects recommended therapy for religious reasons) or covert (as with children who are supposed to take an antibiotic, say they are taking it but are not, as revealed by a blood test to detect that antibiotic).

The person who demonstrates noncompliance is said to be noncompliant.