title: Impact of an antimicrobial stewardship program on the use of carbapenems in a tertiary women's and children's hospital, Singapore.
abstract: OBJECTIVE
  Antimicrobial stewardship programs (ASPs) promote the judicious use of antimicrobials by limiting inappropriate use. This article evaluates the impact of a prospective-audit-and-feedback ASP implementation on the appropriate utilization of carbapenems in a tertiary pediatrics and obstetrics/gynecology hospital in Singapore (KKH) after the establishment of an ASP in July 2011.
  
  
  METHODS
  This was a prospective, single-center, pre-post intervention study designed to analyze the appropriate prescribing of carbapenems pre-ASP (October 2009 to June 2011) and post-ASP (July 2011 to December 2013). Utilization of carbapenems was evaluated by daily defined doses (DDDs), days of therapy (DOTs), prescriptions, as well as cost per 100 patient-days pre-ASP and post-ASP using a segmented regression of interrupted time series analysis.
  
  
  RESULTS
  Of 404 prescriptions for carbapenems reviewed post-ASP, 70.3% were appropriate compared with those prescribed pre-ASP (55.9%; p=0.027). Reasons for inappropriate prescribing included inappropriate choice (36.1%) and duration (31.3%). A total of 61.2% of the interventions (213 of 348) were accepted. For pediatrics, there was a significant decrease in DDDs per 100 patient-days by 55.6% from a baseline of 0.9-0.4 (p=0.013) post-ASP and a reduction in DOTs per 100 patient-days by 46.7% from a baseline of 1.5-0.8 (p=0.06) post-ASP without significant changes in prescription rates. Pediatrics utilization cost increased from a pre-ASP mean of $175 per 100 patient-days to a peak of $238 (p<0.001) and decreased significantly post-ASP to a mean of $149 (p=0.01). For obstetrics/gynecology, there were no significant changes in DDDs (0.3 vs 0.3, p=0.99), DOTs (0.2 vs 0.3, p=0.36), prescriptions (0.03 vs 0.04, p=0.38), or cost ($45 vs $52, p=0.63) per 100 patient-days pre- versus post-ASP.
  
  
  CONCLUSIONS
  ASPs improved the appropriateness of carbapenems prescribing overall and reduced utilization in pediatrics. Identification of areas of inappropriate prescribing will be valuable in guiding future ASP efforts.
authors.affiliation: Department of Pharmacy, KK Women's and Children's Hospital, Singapore.
authors.forename: Xue Fen Valerie
authors.initials: XF
authors.lastname: Seah
authors.forename: Yue Ling Rina
authors.initials: YL
authors.lastname: Ong
authors.forename: Shi Wei
authors.initials: SW
authors.lastname: Tan
authors.forename: Gita
authors.initials: G
authors.lastname: Krishnaswamy
authors.forename: Chia Yin
authors.initials: CY
authors.lastname: Chong
authors.forename: Natalie Woon Hui
authors.initials: NW
authors.lastname: Tan
authors.forename: Koh Cheng
authors.initials: KC
authors.lastname: Thoon
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000191:economics / Q000627:therapeutic use*; D015780:Carbapenems / Q000008:administration & dosage / Q000009:adverse effects / Q000191:economics / Q000627:therapeutic use*; D002648:Child; D017046:Cost Savings; D004334:Drug Administration Schedule; D016527:Drug Costs; D055695:Electronic Prescribing; D005260:Female; D006284:Health Plan Implementation; D006801:Humans; D057970:Inappropriate Prescribing / Q000191:economics / Q000517:prevention & control*; D017053:Infection Control / Q000191:economics; D007239:Infections / Q000188:drug therapy* / Q000191:economics / Q000401:mortality; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000191:economics; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000191:economics; D011446:Prospective Studies; D012846:Singapore; D062606:Tertiary Care Centers
chemical_list: D000890:Anti-Infective Agents; D015780:Carbapenems
keywords: antimicrobial stewardship; carbapenems; obstetrics/gynecology; pediatric