I agree with Dr Adshead that root cause analysis (RCA) does not necessarily add anything to the investigation process after an adverse event, in terms of determining causation, other than making it systematic and comprehensive. What is not made clear in our article is that RCA is not a means to an end in itself. The aim of RCA is the development of improved safety systems in patient care, which compensate for human error. The philosophy behind RCA is that human beings make unintentional errors and they will continue to make errors in future. The aim of the investigation phase in RCA is to determine where errors have occurred and their root cause. This information is used to design improved safety systems (e.g. barriers) to prevent any harm caused by similar errors in future. The intention of locating the errors is not in order to blame or discipline individuals.

With this in mind, the strength of the causal relationships, alluded to by Dr Adshead, is probably not of such importance to the individual as it was with the inquiries held under the auspices of HSG(94)27. The worst that can happen, after a flawed RCA, is the design of a redundant patient safety system. Staff who are found to have made an unintentional error may be upset if they feel wrongly criticised, but they can be reassured that they are never going to be the focus of the investigation or the outcome. It is extremely important that healthcare staff are made aware of the blameless nature of these RCA investigations or the cultural shift that is required to bring about the open reporting of errors (as occurs in the aviation industry) will never occur.

Declaration of interest

L.A. Neal is working with the Emergency Care Research Institute (a non-profit patient safety organisation) collaborating with the Department of Health to introduce root cause analysis into the National Health Service.