The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) monitors and evaluates health care providers according to strict standards and guidelines. Improvement in the quality of care is a principal concern. Hospitals are required to identify and monitor important quality indicators that affect patient care and establish “thresholds for evaluation” (TFEs), which are levels at which a special investigation of problems should occur. TFEs provide a means of focusing attention on nonrandom errors (i.e., special causes of variation). A logical way to set TFEs is through control charts. Eckhardt Hospital collected data on the number of infections that occurred for samples of 200 surgeries each month over a three-year period. These data are available in the data file Eckhardt Hospital Case Data.xlsx. Hospital administrators are concerned about whether a high number of infections (such as in month 12) are caused by factors other than randomness.

Case Questions for Discussion:

1.Using the case data, what is the average percentage of infections?

2.Construct an appropriate control chart, compute the upper and lower control limits, plot the data on the chart, and determine if the process is in statistical control. Based on your analysis, what action, if any, should management take?

3.What threshold for evaluation should management use to monitor future samples as a basis for taking action?