Statistical process control in nursing research

Res Nurs Health. 2012 Feb;35(1):82-93. doi: 10.1002/nur.20467. Epub 2011 Nov 17.


In intervention studies in which randomization to groups is not possible, researchers typically use quasi-experimental designs. Time series designs are strong quasi-experimental designs but are seldom used, perhaps because of technical and analytic hurdles. Statistical process control (SPC) is an alternative analytic approach to testing hypotheses about intervention effects using data collected over time. SPC, like traditional statistical methods, is a tool for understanding variation and involves the construction of control charts that distinguish between normal, random fluctuations (common cause variation), and statistically significant special cause variation that can result from an innovation. The purpose of this article is to provide an overview of SPC and to illustrate its use in a study of a nursing practice improvement intervention.

Publication types

  • Review

MeSH terms

  • Clinical Nursing Research / methods
  • Data Interpretation, Statistical*
  • Humans
  • Nursing Research / methods*
  • Research Design