Duplicative Medications in Patients Who Visit Multiple Medical Institutions and Their Implications for Drug Expenditures in Japan
Posted: 21 Jun 2007
Objectives: Duplicative medications in patients who visit multiple medical institutions are a serious problem not only safety of drug therapy but also drug expenditures. The objectives of this paper are to describe the frequency of duplicative medication use and to estimate the drug costs associated with such use in patients who visit multiple medical institutions. Methods: The subjects of this study were insurants of a corporate health insurance society in Japan. We examined claims of insurants who were prescribed oral medications from multiple medical institutions in April, 2002. We examined the characteristics of insurants who received duplicative medications, calculated the cost of duplicated drugs, and estimated the total savings that may be achieved by avoiding them nationwide.
Results: Among the insurants of the health insurance society who were prescribed oral medications from multiple medical institutions, 8.8% received drugs with the same mechanism of action for overlapping administration periods. The percentage of patients who received duplicative medications was higher for patients who received a large number of prescriptions per month. In terms of comparison among three age groups, 0-19 years old, 20-69 years old, and 70 years and older, the percentage was higher in 0-19 years old patients than in other age groups. Patients who were dispensed all drugs from external dispensing pharmacies (vs. from physicians or hospital pharmacies) tended to receive less duplicative medications. The cost of duplicated drugs is 0.7% or 0.5% of the total drug cost, when calculated with higher-priced drugs and lower-priced drugs respectively.
Conclusions:This study suggests that pediatric and teenage patients as well as elderly patients require prudent management of medication to avoid duplicative medications. Assuming that the situation throughout the country is the same as that found in our study, it is estimated that 5.2-7.2 billion yen could be saved if duplicative medications were completely eliminated in Japan. Our examination of the relationship between duplicative medications and the separation of dispensing and prescribing functions supported the hypothesis that this separation reduces the frequency of duplicative medications. To reduce duplicative medications, physicians and pharmacists need to be more aware of collecting information regarding patients' visits to other medical institutions and prescriptions received. Introduction of IC health insurance cards in the future can record information on patients' visits to medical institutions and prescriptions received, and contribute to the reduction of duplicative medications.
Keywords: drug expenditures, drug safety, drug policy, duplicative medications, drug-drug interactions
JEL Classification: I18
Suggested Citation: Suggested Citation