A defining characteristic of quality improvement is to demonstrate that the strategy
for change works to bring about a measurable difference in process or outcome.
Measurement for improvement monitors systems and processes over time (dynamic,
continuous measurement); whereas traditional statistics are usually used to identify
differences between groups (static, cross-sectional). The two main measurement tools
are run charts and statistical process control charts. Run charts and control charts
use the principle of replication to demonstrate whether a change has occurred from
preintervention (baseline phase) to postintervention (implementation phase).
Applying the rules for interpretation can help determine whether the variation in a
process is due to common or special causes. These rules include identification of runs,
trends, and out-of-control points. The interpretation of this variability directs action on
the processes of a system. Measurement for improvement and the interpretation of the
variability in processes or outcomes is a key to the success of quality improvement efforts
in health care.
You are a member of your unit’s cardiothoracic surgery quality improvement team. Surgery
has always been fascinating to you, and heart and lung surgery is the most interesting of all.
You enjoy the clinical work, and this hospital is a new member of a regional consortium that
is focused on improving all aspects of their coronary artery bypass graf (CABG) surgeries.
What an opportunity to combine your love of surgery as a discipline and learn to improve care
for surgical patients!
Throughout the first week, you notice that the team waits for a serum potassium level before
the patient can come off the heart/lung bypass machine. This is important because patients
who are on the bypass machine for a longer period have more complications. In the first six
cases this week, it has taken between 12 and 40 minutes for the “stat” potassium level to be
reported by the lab. Everyone in the operating room (OR) “knows that the lab is slow,” but
you wonder what is really happening with this process.
One morning later this week, the first case of the day for your team is canceled. Instead of
catching up on some reading, you decide to follow a stat potassium sample from the other