Until the processes that generate the output become the focus of our efforts, the full power of these methods to improve quality, increase productivity, and reduce cost may not be fully realized.
—AIAG STATISTICAL PROCESS CONTROL MANUAL
Six months after a successful improvement in a hospital Emergency Department (ED), turnaround times drifted back to previous levels over the next six months. In another hospital, intensive care unit (ICU) delirium rates began to drift back toward previous levels after significant improvement. Teams were initiated to reinvigorate the delirium improvements. From my point of view, these teams are rework.
Performance drift happens when improvement teams fail to fully address the control phase of DMAIC. Without control charts to monitor performance and corrective action to address performance issues, no improvement will stick around for very long.
When it comes to patient safety, hospitals have rapid-response teams (RRTs) to address a decline in the patient's vital signs. But hospitals haven't applied the same thinking to the vital signs of their performance.
Preventing Performance Drift
If we think of a control chart of ED turnaround times, ICU delirium rates, patient falls, or infection rates as being like a heart monitor for hospital performance, we could then have corrective-action teams (CATs) that respond when the hospital's vital signs begin to slip. Who should be responsible for monitoring performance and calling an alert? Anyone working in the ED, ICU, nursing unit, radiology, lab, or other department of the hospital.
While the initial excitement may sustain an improvement for a while, ongoing performance may require the addition of checklists, training, and other tools or systems to ensure continued success. The improvement may need some tweaking to sustain itself.
Some people think that monitoring performance with a control chart takes too much time, but does it take more time than having to redo the improvement six months later? Does it cost more than reworking the improvement? Does it cost more than the lives lost because of performance drift?
Once you've made improvements, you'll want to sustain (i.e., control) them to ensure that you stay at the new level of performance. Otherwise, you'll gradually slip back to the old levels of performance. I've heard too many stories of excellent hospital improvements sliding back in the following weeks or months. This is why you will want a process control system. This is the essence of sustaining change.
A process control system describing standard work includes written descriptions, flowcharts, control charts, and/or histograms to monitor and maintain your new level of performance. Process control systems consist of:
The system—suppliers, inputs, process, outputs, and customer (QI Macros SIPOC template)
Charts of performance—control charts (e.g., XmR ...