Safety: Adverse Events
Why is this measure important?
Adverse events are defined as things that happen in hospitals that are not intended, and that cause harm or risk of harm to patients. Many adverse events can be prevented through changes in care or systems.
Some adverse events are considered preventable: for example, prescribing the wrong medication or operating on the wrong patient. Other adverse events are not preventable: for example, a drug reaction in a patient who has never had a drug reaction before, or a side effect of chemotherapy in a patient who must have the chemotherapy to be cured of his or her cancer.
How do we track this measure?
We track all adverse events on an ongoing basis through a hospital-wide reporting system and then use the following categories to identify the most serious events requiring changes in our care or systems:
- Levels 1 & 2 – Adverse events that do not harm patients, or cause only a temporary change in condition. For example, an intravenous bag leaks and has to be changed. Although these events do not cause harm, learning about them may help us improve our care or systems.
- Level 3 – Adverse events that cause only atemporary change in condition, but are potentially serious. For example, a patient’s condition deteriorates, and he or she has to be transferred into the intensive care unit for monitoring.
- Level 4 – Adverse events that cause patient harm, may result in additional health problems, or are very dangerous to the patient. For example, a patient bleeds after surgery and has to be returned to the operating room or needs blood transfusions; or a patient has a stroke during treatment for cancer.
- Level 5 – Adverse events that result in an unexpected patient death. Unexpected patient deaths always require a comprehensive review of the hospital’s care and systems.
The events that we track most closely, and that are shown in the graph, are serious events (Levels 3-5) that we believe were preventable.
How do we compare to other hospitals?
Since no two hospitals define adverse events in the same way, it is impossible to use this measure to compare hospitals. We track this measure to monitor our own performance against a standard of zero, not to compare our performance with others.
After a slight increase in significant preventable adverse events (Levels 3 and 4) in 2009, there was a slight decrease in such events in the first half of 2010. In the first quarter of 2010, we experienced the first Level 5 event since 2005.
What are we doing to improve?
In addition to tracking all adverse events, the most serious preventable adverse events are reviewed by a committee of senior clinicians, administrators and families, who recommend and implement changes in our care or systems to prevent the event from occurring again. Our goal is to have no serious preventable adverse events.