What is Root Cause Analysis?

A root cause analysis is a method and collection of healthcare improvement tools used to retrospectively identify the causes of adverse events. These analyses are used to identify measures to prevent future healthcare issues and improve patient safety. Since 1997, The Joint Commission has mandated that healthcare facilities use RCAs to analyze unanticipated events that cause death or serious injury to patients (ex: wrong-site surgeries).


Key Takeaways

  • RCAs look beyond human error to identify systems-level failures occurring in adverse events and prevent them from happening again.

  • The goal of RCAs is to improve patient safety using a variety of quality improvement tools and action plans to address potential causes of harm.


What is a Root Cause Analysis

Performing an RCA

When performing an RCA to evaluate an adverse event, the goal is to answer: what happened?, why did it happen?, and what can be done to prevent it from happening again? While each RCA will be different depending on the studied event and available resources, the systematic approach to RCAs generally follows these steps:

  1. Identify the adverse event

    • People involved in event openly and honestly report what happened

    • Quality committee reviews clinical documentation of the event to figure out the basics of what happened

  2. Organize a team

    • Collect 4-6 members of experts with fundamental quality improvement, clinical, or supervising knowledge 

    • Choose an unbiased team leader and ensure that everyone on the team is treated as equals

  3. Develop an initial flow diagram

    • Create a flowchart to describe everything leading up to the event that is understandable to everyone on the team

  4. Develop an event story map

    • Conduct thorough interviews with everyone involved in the event

    • Thoroughly review clinical documentation of the event and use triggering questions to guide further investigation

  5. Develop a cause and effect diagram

    1. Communication problems, policies, rules, procedures, human errors

    • Identify a single problem statement describing the event

    • Identify actions and conditions that caused the problem

  6. Identify root cause contributing factors

    • Describe how a cause led to an effect and increased the likelihood of the adverse effect

    • Apply 5 Rules of Causation to identify root cause/contributing factors (RCCFs)

  7. Develop corrective actions

    • Identify barriers and risk reduction strategies to prevent adverse event from recurring

    • Implement a trial test of corrective actions

  8. Measure outcomes

    • Develop outcome measurements to ensure correct implementation of actions

    • Track quantifiable data to document effectiveness overtime

  9. Communicate results 

    • Communicate RCA results to all staff involved in event

Identifying causes of contribution factors

To determine if root causes and contributing factors led to the adverse event, staff should use the 5 Rules of Causation developed from the 1999 FAA technical report, Maintenance Error Causation.

Rule 1: Clearly show the cause and effect relationship

Ex: Residents are scheduled 80 hours per week, which led to increased levels of fatigue, increasing the likelihood that dosing instructions would be misread.

Rule 2: Use specific and accurate descriptors for what occurred, rather than negative and vague words.

Ex: The pump manual had an 8-point font and no illustrations; as a result, nursing staff rarely used it, increasing the likelihood that the pump would be programmed incorrectly.

Rule 3: Human Errors must have a preceding cause.

Ex: Drugs in the CPOE system are presented to the user without sufficient space between different doses on the screen, which led to the wrong dose being selected, increasing the likelihood of an overdose.

Rule 4: Violations of procedure are not root causes and must have a preceding cause.

Ex: Noise and confusion in the prep area, coupled with production pressures, 

increased the likelihood that steps in the CT scan protocol would be missed, which led to the injection of an air embolism from using an empty syringe.

Rule 5: Failure to act is only causal when there is a pre-existing duty to act.

Ex: The absence of an assignment for designated RNs to check orders at specified times, led to STAT orders being missed or delayed, which increased the likelihood of delays for patients needing immediate therapy.

Conducting a successful analysis

To perform a successful RCA, it should be thorough and credible to fully meet the RCA goals. The Veterans Health Administration’s National Center for Patient Safety has stated that to have a thorough and credible RCA, you must include:

  • Determination of human and other factors

  • Determination of related processes and systems

  • Analysis of underlying cause and effect systems through a series of why questions

  • Identification of risks and their potential contributions

  • Determination of potential improvement in processes or systems

  • Include participation by the leadership of the organization and those most closely involved in the processes and systems

  • Be internally consistent

  • Include consideration of relevant literature

RCA Tools

When conducting an RCA, you can use a variety of tools to identify root causes and contributing factors of the adverse event.

  1. Ishikawa Diagram, or fishbone diagram: cause and effect diagram outlining the adverse event (fish head), root causes (fishbones), and sub-causes (branches off backbone and fishbones).

  2. Five Whys: a question and answer technique used by repeatedly asking why the main problem happened to identify root causes.

  3. Pareto Chart: a bar graph that shows how a collection of contributing factors affect an outcome. It is a visual representation of the Pareto principle, that 80% of an effect is caused by 20% of the causes.

  4. Scatter Diagram: visual representation of the strength of a causal relationship between a contributing factor and the adverse event.

Challenges of RCAs

Studies have shown that most RCAs tend to propose weak solutions to problems and are less likely to decrease recurrence of adverse events. When performing RCAs, some teams tend to look for only one cause of the adverse event, instead of looking for multiple contributing factors that interact on a systems-level to cause these problems. In a BMJ Quality & Safety article, researchers identified several common areas of inefficiency in the RCA process, including lack of independence from the organization where the event occurred, poor feedback loops to all staff about RCA results, and having too many actors that contribute to an outcome without an effective way to hold all parties accountable.


Outside the Huddle

How to perform a root cause analysis for workup and future prevention of medical errors: a review | PubMed

Guide to Performing a Root Cause Analysis | Veterans Health Administration 

Our current approach to root cause analysis: is it contributing to our failure to improve patient safety? | PubMed


Reviewed by Geetika Rao, MPH | Fact checked by Jared Dashevsky, M.Eng