Adverse Drug Events

What is an adverse drug event?

An adverse drug event (ADE), or drug error, is an injury resulting from the use of any drug.

Why do we measure?

  • Adverse drug events can have a negative effect on a patient’s recovery

  • Improving is part of providing a safe healing environment

  • We continue to strive to reduce the number of ADEs to zero

How do we measure?

  • Employee reporting of ADEs is voluntary

  • We track medications that are used only to reverse side effects of other medications

  • All ADEs are placed on a nine-point clinical severity scale depending on the seriousness of the error

  • Rate of error is calculated by the number of ADEs per 1000 doses of medication

How are we improving?

We concentrate on providing the right medication to the right patient, at the right time. Since 2009, our error rate has continued to decline.

  • Non-harm-causing ADEs (1-3)

    • Error rate below 1.4 since 2009

    • Error rate below 1.0 in 2013

  • Short-term-causing ADEs (4-6)

    • Error rate below 0.2 since 2009

    • Error rate below 0.05 in 2013

  • Long-term-causing ADEs (7-9)

    • Error rate below 0.002 since 2009

chart depicting the decline of Adverse Drug Events from 2010 to 2017

How Do I Read This Chart?

We report our data using what is known as a control chart. There are four elements on the chart. 1) The blue diamonds: these are the actual data points for each month. They depict the event rate as defined on the vertical axis. 2) and 3): The dotted red lines: these are the upper and lower control limits. They are scientifically calculated to represent the statistical range within which normal random variation occurs in a stable system. 4) The solid red line. This is the average of the blue diamonds for that time frame. As long as the blue diamonds are within the dotted red lines, the system being measured is a stable one. There are certain patterns of blue diamond configuration (e.g. diamonds outside the control limits), that mean something in the system has changed. This is called special cause variation and will usually involve a deeper investigation as to why the new pattern of variation. Each control chart contains an arrow which indicates the desired change direction. For most harm events, the desired direction is down (i.e. less harm is better). For other measures (compliance rates, days between harm events) the desired direction is up.