G and T Charts, and Feedback from the National Association of Healthcare Quality Annual Conference
With the National Association of Healthcare Quality’s annual conference starting in Tampa on September 20, I thought it would be apropos to talk about some features we added to Minitab Statistical Software based on feedback we received from previous NAHQ attendees.
Charting Rare Events
It is important, and increasingly required, for hospitals to monitor and record certain negative events that occur in hospitals. Some examples include reporting on nosocomial (hospital-acquired) infections, medication errors, patient falls, ventilator-associated pneumonias (VAP events), and other rare adverse events.
As described in Barbara Cleary’s Quality Digest article, a simple P chart may not be the most appropriate plot to use when monitoring uncommon events. In Minitab 16.2, we added two charts specifically for plotting rare events—G and T charts. G charts are used to monitor the number of normal and routine events, such as surgeries or doses, occurring between rare events. The G chart will put up a “red flag” when the interval of events become very small and occur in succession. This indicates adverse events may be occurring more frequently than you would expect.
Conversely, if a data point appears above the upper control limit, pat yourself on the back! A high point on the G chart indicates there was an extended period between adverse events. Find out if there was any special cause for this great achievement and replicate it!
T charts are very similar to G charts except they can be used to plot dates/times of rare events instead of dates or number of opportunities between rare events. Regardless of how the data are collected, when the event occurs infrequently, consider a G or T chart.
For more information on the G Chart, check out our whitepaper on http://www.minitab.com/. Click here to see how the Red Cross hospital used Minitab’s control charting tools to save hundreds of thousands of dollars a year!
And if you're going to be at NAHQ this year, be sure to visit me at Booth #311 – I’d love to hear about your quality journey!