Objective: Recently, the cost of medical care in Japan has increased as a result of an aging society.  In response to this reality, the Japanese government initiated a campaign to promote the use of generic drugs.  In spite of this campaign, Japanese consumers have doubts about the safety and reliability of generic drugs, resulting in lower usage of these drugs compared to usage in Europe and the US.
Methods: In order to clarify some of the factors that contribute to low rates of generic drug use, we carried out a survey of 400 pharmacies.  The survey data was analyzed using factor analysis and cluster analysis, which is a technique known as multivariate analysis.
Results: The results from factor analysis derived four factors: 1) generic drug usage related to generic drug prescription class, 2) the amount of generic drug prescriptions related to patient preferences, 3) patient willingness to use generic drug prescriptions, and 4) pharmacy willingness.  Cluster analysis was used to classify pharmacies participating in the survey.  The results of cluster analysis revealed three main pharmacy groups: a) low usage of generic drugs, b) moderate usage of generic drugs, and c) high usage of generic drugs.
Conclusion: The results of multivariate analysis showed that pharmacists are more willing to issue generic drugs unless doctors instruct them to use a brand-name drug.