Nonadherence in Hypertension: How to Develop and Implement Chemical Adherence Testing.

Nonadherence to antihypertensive medication is common, especially in those with apparent treatment-resistant hypertension (true treatment-resistant hypertension requires exclusion of nonadherence), and its routine detection is supported by clinical guidelines. Chemical adherence testing is a reliable and valid method to detect adherence, yet methods are unstandardized and are not ubiquitous. This article describes the principles of chemical...