On March 3, the CUSUM is nearing the CUSUM Limit calculated in formula E. This should serve as a warning. While patient results are still "in control," there may be a trend -- indicating that results will soon be "out of control" and unacceptable.
- Fortunately for this case, the CUSUM Limit drops and stays below the 4.3 calculated value. If the CUSUM reaches the Limit, patient results cannot be accepted as accurate.
- It is important to observe daily any trends in the CUSUM values so that corrective action can be taken before the limit is reached.