In TIPSQI our argument is that audit is often mistakenly used as a method for improvement. It can be done, but it is far inferior to using the tools we have covered in this guide.
The main way in which the methods differ most is that QI is a continuous process, primarily represented by continuous data collection for the run chart, and continuous testing and learning through PDSA. Compare this to how an audit cycle is often performed with a single data collection and recommendations -> intervention(s) from the recommendations -> further single data collection months later. Between data collections we have a large gap where, as we have no data, we have no idea what’s going on. We have no idea whether either data sample is truly representative of practice, or outliers that we happened to catch. Data over time will capture performance over many more time points, and therefore many more conditions – providing a more representative picture.