The Fishbone Diagram: An Effective Tool for Root Cause Analysis in Healthcare
- Jeanette Zocco
- 4 days ago
- 3 min read
The current state of healthcare is complex and many factors can impact patient safety. When quality-associated problems cause actual or potential patient harm, identifying the root cause is critical for improving patient safety, quality of care, and operational efficiency. The fishbone diagram, also known as the Ishikawa or cause-and-effect diagram, is an effective tool for root cause analysis in healthcare. It helps teams to systematically assess potential factors contributing to a specific quality-associated issue, differentiating between symptoms and root causes (Kumah et al., 2024). It was originally developed by Kaoru Ishikawa, an engineering professor at the University of Tokyo and well known quality improvement leader in Japan (wikipedia, 2025). This strategy can be used as an initial approach to inform mitigation efforts associated with root causes.
Structure
The fishbone diagram resembles a fish skeleton, with a horizontal arrow pointing to the problem, or the “head” of the fish. Branching off from this spine are various “bones,” each representing categories of potential causes. The 5-why approach- asking why 5 times to allow a deeper analysis of the true cause- is frequently used in combination with this tool.
Common categories include:
People: Staff skills, training, communication
Methods: Procedures, protocols, workflows
Equipment: Medical devices, technology
Environment: Physical setting, cleanliness, lighting
Materials: Supplies, medications (Kumah et al., 2024)
Process
Define the Problem: this is the issue to be analyzed or metric to be improved upon, and represents the head of the fish (ex. medication error, high primary cesarean delivery rate).
Construct the Diagram: Draw a horizontal arrow pointing to the problem statement. Branch out the major categories as “bones” off the spine.
Brainstorm Main Causes: Engage a multidisciplinary team including frontline staff to brainstorm and list possible causes under each category (see common categories above). These are the long fishbones.
Determine subcauses- Use the 5-why approach. These are the shorter lines that fall under the longer lines
Analyze and Prioritize: Review the causes and identify which ones are the most impactful. There are usually some low hanging fruit that can be easily fixed to create quick wins. Use data, observations, or evidence-based resources to validate.
Implement Solutions: Develop targeted interventions based on the root causes identified, and monitor their effectiveness over time.
Use of the fishbone diagram in reducing primary cesarean delivery
A mid-sized teaching hospital sets out on an initiative to reduce nulliparous, term, singleton, vertex (NTSV) primary cesarean delivery. Key stakeholders, including physicians, residents, midwives, bedside nurses, and leadership are brought together to brainstorm around root causes. The fishbone diagram is used to structure the session. Here’s an example of what this may look like (see Figure 1).
Figure 1: Fishbone Diagram
Based on this Fishbone diagram, one cause of the increased NTSV rate may be lengthy inductions. Lack of an evidence-based protocol or guideline to facilitate a standardized process represents the root cause. The team may decide to create a cervical ripening guideline and newly associated processes. This may include the following elements: developing a standardized induction scheduling process, obtaining a bishop score on admission, and cervical ripening based on the bishop score. Urinary balloon catheters with the appropriate inflation size may be ordered to facilitate mechanical ripening. Of note, ensuring the correct inflation size is a key safety feature- as balloons may rupture when not designed to expand to cervical ripening volumes (minimum 30 ml). Consideration may also be given to ensuring these are stocked separately from standard urinary catheters for bladder drainage and clearly labeled for cervical ripening.
Summary
The fishbone diagram is an effective tool for root cause analysis in healthcare. Its depiction of potential causes across various categories assists teams in identifying underlying issues, and guides problem-solving. By systematically examining factors contributing to problems, healthcare organizations can implement targeted solutions, enhance safety, and optimize patient outcomes.
*If this article interests you, you may also enjoy my book titled: Obstetric and Neonatal Quality and Safety (C-ONQS) Study Guide: A Practical Resource for Perinatal Nurses, available on amazon: Amazon_obneonatalstudyguide
Copyright by Jeanette Zocco MSN, RNC-OB, C-EFM, C-ONQS
References
Kumah A, Nwogu CN, Issah AR, Obot E, Kanamitie DT, Sifa JS, & Aidoo LA.(2014, May 2). Cause-and-Effect (Fishbone) Diagram: A Tool for Generating and Organizing Quality Improvement Ideas. Global Journal on Quality and Safety in Healthcare, 7(2):85-87. doi: 10.36401/JQSH-23-42. https://pmc.ncbi.nlm.nih.gov/articles/PMC11077513/#i2589-9449-7-2-85-b03
Kaoru Ishikawa.(2025, April 3). In Wikipedia.
