SPC in Healthcare
Statistical process control (SPC) is used within many industries as the key tool toward improving product and process quality, as well as increasing yield and reducing cost (concerns of importance in the healthcare industry also). In particular, SPC is a key tool in the pursuit of continuous process improvement. Therefore, the objective of this article will be to explore the application of SPC within healthcare as a tool toward the improvement of quality of care and continuous quality improvement.
Healthcare scientific articles were reviewed for a statement related to the use of SPC. Articles that did not meet these criteria were excluded. J Thor, J Lundberg, and J Ask et al2 contains a reference list of 100 articles on this topic.
A scan of healthcare literature and texts easily reveals a large number of statistical studies where the general and established methods for evaluating quality of care are to conduct post event reviews and root cause analyses of incident reports, with tabulated results, incident narrative analyses, and Failure Modes and Effects Analysis (FMEA). These analysis techniques are all valid. However, it is noticeable that these studies typically conduct their analyses as if the data occurred in a singular timeframe, at the end point of which the studies stop and a conclusion is determined. While a study may have resulted in a conclusive improvement, measure or result, ending the monitoring does not guarantee that the improvement was achieved or sustained. Shewhart (the originator of SPC) established in the 1930’s that once monitoring stops, a process quickly reverts to a chaotic state.
SPC offers the potential for a simple, easily implemented, easy to understand, and statistically sound method to improve the quality of healthcare (no matter how good or how bad at the starting point). SPC is utilized for many different purposes and in many different places throughout the healthcare industry. In particular, it has become apparent that the industry is actively pursuing continuous process improvement as a means to improve the quality of healthcare, and that SPC is considered a valuable tool in that pursuit. Just the amount of literature devoted to the use of SPC in healthcare, when compared to other industries, is impressive; a reflection of the high academic nature of the healthcare industry. There is ample evidence of the strong value and positive potential that SPC could bring to the pursuit of current healthcare issues (reducing healthcare cost, improving interoperability, improving quality of care, acceptance of evidence-based-medicine, implementation of health IT, etc.).
 Wheeler DJ, Chambers DS. Understanding Statistical Process Control (second edition). SPC Press, Knoxville, TN, 1992
 Thor J, Lundberg J, J Ask et al. Application of Statistical Process Control in Healthcare Improvement: systematic review. Qual Saf Health Care 2007; 16:387-399
 Mohammed MA. Using Statistical Process Control to Improve the Quality of Healthcare. Qual Saf Health Care 2004; 13:243-245
 Guthrie B, Love T, Fahey T, Morris A, Sullivan F. Control, Compare and Communicate: designing control charts to summarize efficiently data from multiple quality indicators. Qual Saf Health Care 2005; 14:450-454
Submitted by Ed Carroll