Therapeutic duplicate prescribing in Korean ambulatory care settings using the National Health Insurance claim data.

Background: Duplicate prescribing is known to occur across health systems and is one of the most frequent drug related problems. Therapeutic duplication (TD) increases the risk of adverse drug reactions without additional therapeutic benefits.

Objectives: This study aimed to develop TD criteria concerning four drug categories which are acid-related disorder drugs, antimicrobials, antihypertensives, and lipid modifying drugs and to estimate the prevalence of therapeutic duplicate prescribing at the ambulatory care settings in Korea.