Price 2010.

Methods	STUDY DESIGN: ITS Risk of Bias: MEDIUM
Participants	PROVIDERS: all physicians in the hospital PARTICIPANTS: all patients in the hospital CLINICAL PROBLEM: requiring antibiotic treatment or prophylaxis SETTING: 1 university hospital in the UK
Interventions	FORMAT: Interventions: dissemination of guidelines; restrictive by removal and expert approval Intervention Functions: education, restriction Note that the published paper says: "The policy was widely disseminated in the hospital but no specific measures were put in place to enforce compliance". However, the antibiotic policy provided by the authors says: “Cephalosporins and fluoroquinolones. These agents will NOT be ward stock on any general medical or surgical wards – continuation of therapy beyond 24 hours (in Medicine) and single dose prophylaxis (in Surgery) requires consultant review, prescription by consultant and discussion with Micro ID”. DELIVERER: AMT COMPARISON: usual care DESIRED CHANGE: decrease excessive
Outcomes	PRESCRIBING: Choice: use of cephalosporins and quinolones (combined) in DDD/1000 OBD MICROBIAL: Clostridium difficile infection
Notes	FINANCIAL SUPPORT: Funding: part commercial, Optimer Pharmaceuticals and US Department of Veterans Affairs. Competing Interests: 1 author declared multiple commercial sources of research funding and held patents relevant to C difficile infection licensed to ViroPharma ADDITIONAL INFORMATION: authors provided the 2008 version of the hospital antibiotic policy, which included details about the restrictions on use of target drugs Microbial Risk of Bias MEDIUM: case definition yes, planned intervention yes, infection control no (a cohorting ward was introduced at the same time as the antibiotic policy)
Risk of bias
Bias	Authors' judgement	Support for judgement
Intervention independent (ITS) ?	Low risk	For prescrbiing outcome
Analysed appropriately (ITS) ?	Low risk	Segmented regression analysis
Shape of effect pre‐specified (ITS) ?	Low risk	Point of intervention was point of analysis.
Unlikely to affect data collection (ITS) ?	Low risk	Pharmacy computer
Knowledge of the allocation adequately prevented(ITS)?	Low risk	Pharmacy computer
Incomplete outcome data addressed (ITS) ?	Low risk	Pharmacy computer
Free of selected reporting (ITS) ?	Low risk	Pharmacy computer
Free of other bias (ITS) ?	High risk	1 year data pre‐ and postintervention Microbial Risk of Bias: cohorting introduced at the same time as prescribing intervention.