Surveillance of antimicrobial prescribing (point-prevalence studies and audits)


Evaluating antimicrobial prescribing is a relevant activity within Antimicrobial Stewardship Programs (ASP) because it facilitates:
  • the identification of the priorities and goals of the program
  • the evaluation of the impact of several interventions
  • the verification of the objectives set for the program

There most common approaches to evaluate antimicrobial prescribing are:
  • point-prevalence surveys
  • therapeutic audits

Both strategies require, in different depth, obtaining and processing data from medical records or patient notes and thus, these activities, are time consuming

Point-prevalence surveys

  • Point-prevalence surveys (PPS) are transversal evaluations of antimicrobial prescribing, aiming to obtain an overall picture of antimicrobial prescribing at a certain institution or unit.

  • It is like taking a no-zoom snapshot of antimicrobial prescribing, which may be useful to rapidly identify areas of improvement and to monitor evolution of antimicrobial prescribing if regularly repeated.

  • Detail has frequently to be sacrificed in benefit of simplicity

  • There is no a standardized model, but most point-prevalence surveys collect data from one data source (the medication chart) and obtain a minimum amount of information about prescribing[1] [2]
  1. the percentage of patients prescribed antimicrobials
  2. the range and volume of agents prescribed
  3. number of antimicrobials per patient
  4. duration of therapy
  5. dosing and dosage interval
  6. and time for intravenous-to-oral switching
  7. prophylactic use, which can be assessed by reviewing surgical patients who were prescribed antimicrobials within 24 hours of a surgical procedure.
  8. obtaining clinical data such as a) indication b) type of therapy (empiric or targeted) c) severity of infection d) specific host factors (immune compromise, prosthetic material), can provide further information to better assess the appropriateness of antimicrobial prescribing but might not be practical (time-consuming).

  • Ideally, PPS should be conducted in a single day. Nevertheless this might not be feasible in large institution. ESAC PPS, currently adopted by ECDC states that data should be collected in a single day for each ward/unit. The total time frame for data collection for all wards of a single hospital should not exceed two to three weeks. It is practice in some hospital units to admit additional patients on Mondays for elective procedures (especially surgery); it is therefore recommended that the survey in these units is conducted between Tuesday and Friday.

Links to several point-prevalence surveys

Therapeutic audits

  1. ^ Antimicrobial Prescribing in Australian Hospitals 2011. Chapter 5. Measuring the Performance of Antimicrobial Performance. Pages 61-62
  2. ^ Point prevalence survey of healthcare-associated infections and antimicrobial use in European acute care hospitals – protocol version 4.3. ECDC. May 2012