A article in the Journal of Quality in Clinical Practice [The Application of Statistical Process Control Charts to the Detection and Monitoring of Hospital-Acquired Infections,

A article in the Journal of Quality in Clinical Practice [€œThe Application of Statistical Process Control Charts to the Detection and Monitoring of Hospital-Acquired Infections,€ (2001, Vol. 21, pp. 112€“117)] reported the use of SPC methods to monitor hospital-acquired infections. The authors applied Shewhart, CUSUM, and EWMA charts to the monitor ESBL Klebsiella pneumonia infections. The monthly number of infections from June 1994 to April 1998 are shown in the following table.

(a) What distribution might be expected for these data? What type of control chart might be appropriate?

(b) Construct the chart you selected in part (a).

(c) Construct a CUSUM chart for these data with k = 0.5 and h = 4. The article included a similarly construced CUSUM chart. What is assumed for the distribution of the data in this chart? Can your CUSUM chart perform adequately?

(d) Repeat part (c) for an EWMA chart with λ = 0.2.

Feb Mar Sep 2 3 3 April Aug Nov Oct Dec Jan May 5 1 Jun Jul 1994 1995 1996 1997 2 2 3 3 1 1 3 2 4 2 3 4 8. 11 10 6. 10 6. 5 1 2 4 6. 3 1998