7.2 Quality measures: AMU and point prevalence surveys

A point prevalence survey (PPS) is used to measure how antimicrobials are used in hospitals, and are one of the most common methods for monitoring AMU. AMU is the quantity of antimicrobial administered to an individual or group of patients in a particular setting; a PPS is a data collection tool used to identify the number of people with a disease or condition at a specific time.

PPSs may also be used to collect information specific to hospital-acquired infections. For AMU, PPS collects information on prescribing practices for antimicrobials, and other information relevant to treating and managing infectious diseases in hospitalised patients. This data complements the surveillance data on antimicrobial consumption. As shown in Figure 10, the results of PPS can be used to:

• evaluate quality indicators
• follow up antimicrobial stewardship and infection control programmes
• support decision-making.

Point prevalence is defined as the proportion of people with a particular characteristic at a certain point in time. It is determined by taking the total number of people with the characteristic divided by the total number of people in the population of interest. An AMU PPS survey measures the number of people taking antimicrobials at a given point in time.

Although we are talking about PPS at the end of the course, it is a tool that could be used effectively when initiating an AMS strategy; and if repeated at regular intervals, it can drive the evolution of AMS and IPC.

Specific goals of an AMU PPS are to:

• estimate the prevalence of AMU
• describe patients, invasive procedures, infections (sites, microorganisms including markers of AMR) and antimicrobials prescribed (compounds, indications) to treat the infections or provide prophylactic cover for the procedure
• describe types of patients, specialities or healthcare facilities, and how antimicrobials are used at patient and facility level
• disseminate results to those who need to know at local, regional and national level
• raise awareness of patterns of AMU among staff
• enhance surveillance structures and skills
• identify common problems and set up priorities accordingly
• evaluate the effect of strategies and guide policies for the future at the local, national and regional level (repeated PPS)
• provide a standardised tool for hospitals to identify targets for quality improvement.

A PPS is a qualitative approach: it analyses not only the quantities of antimicrobials used (as DDDs), but also which patients are receiving them, their indication, and whether the antibiotics prescribed are in accordance with local prescribing guidelines.

It should collect information on every patient in a hospital at a time point. Ideally this might be done on the same day – but this is unlikely to be practical, so different wards can be visited for collection over a specified time period, possibly a few days or weeks.

You will need to ensure that hospital management understand and support the survey, and staff will need to be made available and be trained to carry it out. Data is often collected on paper forms but will need to be entered into a database for analysis, so resources must also be allocated to this. Online tools are also available for data collection if smartphones are available.

A standardised global PPS web-based tool is provided by the Global-PPS programme, which co-ordinates regular one-day surveys in participating hospitals around the world.

A WHO document details its methodology, and how facilities can calculate the indicators themselves, rather than entering the data into the global database (WHO, 2018).