The clinical importance of nonadherence relates to the degree to which it interferes with the therapeutic goal. According to Sackett, blood pressure begins to fall significantly only when patients take more than 80% of their medication.18 Thus, even if adherence rates improve to 50-60%, it is still possible that blood pressure levels will remain uncontrolled. Consequently, health care providers are becoming increasingly aware of the significance and detection ofnonadherence in the long-term management of patients with high blood pressure.