[Outpatient antimicrobial drug use and antimicrobial resistance frequency in Suwa area, Nagano, Japan].

: A cross-sectional study was conducted to determine antimicrobial use and to analyze the correlation to resistant bacteria. Records on antimicrobial prescriptions in Suwa area, Nagano prefecture, were collected from December 2009 to May 2010 from a national health insurance database system. Records on antimicrobial-resistant bacteria during the same period were collected from area hospitals. Data was then compared to data published in Europe. The target population was 31,505, or 27.1% of the total area population. More antimicrobials were prescribed in an outpatient setting rather for inpatients. Total outpatient antimicrobial use was 9.34 defined daily dose (DDD) per 1,000 subject days. Macrolides, lincosamides, and streptogramins (MLS) was the most prescribed drug group, followed by beta-lactams other than penicillin and quinolone. The quinolone-resistance rate among Escherichia coli in this area was within a predictable range based on European data, although that of macrolide-resistance among Streptococcus pneumoniae exceeded the predictable range. The health insurance system electronic database proved useful in collecting data on antimicrobial use for curbing action against antimicrobial resistance, including antimicrobial stewardship.