Quality Improvement Feature Series Article 2: Displaying and Analyzing Quality Improvement Data

Abstract
In this second article in the quality improvement (QI) methods series, we discuss how data are best displayed and analyzed in QI projects while focusing on some similarities with and differences from traditional clinical research. We demonstrate why displaying data over time on a run or control chart is superior to using pre–post analysis for QI studies. We introduce several types of statistical process control charts for data commonly collected during QI programs and provide guidance on how to use the proper chart. Last, we present solutions to several common data challenges in QI projects.