Toward safer prescribing: evaluation of a prospective drug utilization review system on inappropriate prescriptions, prescribing patterns, and adverse drug events and related health expenditure in South Korea.

OBJECTIVES

This study aimed to evaluate the effect of the prospective drug utilization review (DUR) system introduced in Korea in December 2010 as a real-time method to improve patient safety, in terms of changes in prescribing practices, adverse drug events (ADEs), and ADE-related healthcare expenditure, using non-steroidal anti-inflammatory drugs (NSAIDs) and their common ADEs as a guide.

STUDY DESIGN

We used an interrupted time-series study design using generalized estimating equations to evaluate changes in prescription rate and ADE-related healthcare expenditure. Cox regression analysis was used to evaluate the probability of NSAID-associated ADEs.

METHODS

A total of 154,585 outpatients with musculoskeletal or connective tissue disorders, without pre-existing gastric bleeding or ulcers were included in this study. The primary outcome was the level and trend change in prescription rate, drug-drug interactions, coprescribed gastro-protective drugs, and defined daily dose (DDD) of NSAIDs. The secondary outcome was the probability of ADEs and changes in ADE-related healthcare expenditure.

RESULTS

There was a significant trend change after introducing the DUR system in terms of drug-drug interactions (-3.6%) and coprescribed gastro-protective drugs (+0.6%). The mean DDD of NSAIDs increased by 0.2. The probability of ADEs decreased overall (-1.7%) and in the high-risk group (age ≥65 years; -9.6%); however, only the latter was significant. There was no significant trend or level change in ADE-related health expenditure.

CONCLUSIONS

The introduction of the DUR system was associated with more efficient prescribing, including a reduction in drug-drug interactions and an increase in the use of gastro-protective drugs. The system had a positive effect on patient outcome but was not associated with reduced ADE-related costs. Further studies are needed to evaluate the long-term effects of the DUR system in Korea.