Am I out of control? The application of statistical process control charts to children's surgery

To illustrate the construction of statistical control charts and show their potential application to analysis of outcomes in children's surgery.

Two datasets recording outcomes following esophageal atresia repair and intestinal resection for Crohn's disease maintained by the author were used to construct four types of charts. The effects of altering the target signal, the alarm signal and the limits are illustrated. The dilemmas in choice of target rate are described. Simulated data illustrate the advantages over hypothesis testing.

The charts show the author's institutional leak rate for esophageal atresia repair may be within acceptable limits, but that this is dependent on the target set. The desirable target is contentious. The leak rate for anastomoses following intestinal resection for Crohn's disease leak is also within acceptable limits when compared to published experience, but may be deteriorating. The charts are able to detect deteriorating levels of performance well before hypothesis testing would suggest a systematic problem with outcomes.

Statistical process control charts can provide surgeons with early warning of systematic poor performance. They are robust to volume-outcome influences, since the outcome is tested sequentially after each procedure or patient. They have application in a specialty with low frequencies of operations such as children's surgery.

Diagnostic test.

Level II.