Over the past 20 years at HealthInsight, I've had the opportunity to work with health care providers and organizations on root cause analysis to learn from sentinel events, patient harms and other negative, unwanted and unexpected events. Seeking to prevent future harms, we've learned that the most important answers to the question "why did this happen?" – the root causes – are often far removed in time and space from the events that occasioned the review.
Cause and effect analysis is a technique employed in root cause analysis that pushes you to consider all possible causes of a problem, rather than just the ones that are proximal and obvious. Forms of cause and effect analysis include the "5 Whys" and causal tree analysis. Analyses using these techniques produce cause-effect chains, with each identified cause itself becoming the effect of preceding causes. When learning and applying either of these analysis techniques, it's not always clear when the analysis stops, because one can always propose a preceding cause – even if you have to go back to the "big bang."