What are the steps for using a fishbone (Ishikawa) diagram to present a mortality review, including patient details, data collection, and root‑cause analysis?

Using the Fishbone (Ishikawa) Diagram for Mortality Review Presentation

The fishbone diagram should be used as a structured framework to systematically analyze surgical mortalities by categorizing contributing factors into 6-7 main categories (Personnel, Material, Method, Machine, Management, Mission, and Cognitive Process), with each "bone" representing specific root causes that led to the death. This approach transforms mortality review from a blame-focused exercise into a system-focused analysis that identifies actionable improvement opportunities 1, 2.

Step 1: Patient Selection and Data Collection

Begin by identifying all mortality cases through your institutional database. For each death, collect:

• Patient demographics: Age, sex, comorbidities, frailty scores
• Clinical presentation: Primary diagnosis, acuity level, time from admission to death (median is typically 3 days) 2
• Categorization of death: Classify as preventable (5.4%), potentially preventable (41.1%), or non-preventable 2
• Complete timeline: Document all diagnostic and therapeutic interventions from presentation through death

Regular multidisciplinary mortality review meetings should include surgeons, anesthesiologists, radiologists, emergency physicians, and geriatricians, with hospital executives involved when system changes are needed 3. This is not optional—it's a mandated standard practice in quality improvement 3.

Step 2: Constructing the Modified Fishbone Diagram

The modified fishbone diagram places the mortality outcome at the "head" of the fish, with 6-7 major "bones" branching off 1, 4, 5:

Primary Categories (The Main Bones):

1. Cognitive Process (most common—present in 89% of cases 4)

   • Diagnostic errors
   • Errors of judgment
   • Premature closure
   • Failed heuristics
   • Inadequate training (accounts for 46% of preventable deaths) 2

2. Personnel

   • Staff knowledge gaps
   • Experience level
   • Education deficits
   • Cultural factors
   • Clinical coder accuracy 6

3. Clinical Data Gathering (39% of cases 4)

   • Incomplete history
   • Missed physical findings
   • Laboratory delays
   • Imaging interpretation errors

4. Organization/System Issues (20% of cases 4)

   • Resource shortages (major contributor) 2
   • Staffing inadequacies
   • Equipment availability
   • ICU bed access

5. Communication (8% of cases 4)

   • Handoff failures
   • Interdisciplinary communication breakdowns
   • Documentation gaps

6. Context of Care (15% of cases 4)

   • Emergency vs. elective setting
   • Time of day
   • Patient volume

7. Affective Factors (15% of cases 4)

   • Fatigue
   • Stress
   • Cognitive overload

Step 3: Root Cause Analysis Using the London Protocol

Critical finding: Cognitive errors rarely occur in isolation—89% occur with other error types, most commonly with specific presentation issues (52%) and clinical data gathering problems (44%) 4. This means you must identify multiple contributing factors across categories.

For each mortality case:

1. Map the sequence of events chronologically on the fishbone
2. Identify all contributing factors (average 2.7 errors per case) 4
3. Link factors across categories to show how they interact
4. Avoid single-cause attribution—most deaths result from cascading failures

Common Pitfalls to Avoid:

• Do not focus solely on the individual clinician—this creates a blame culture and misses system issues
• Do not ignore "near-miss" cognitive errors that didn't result in death but could have
• Do not overlook the "NoLap" population—patients who were eligible for surgery but didn't undergo it and died 3

Step 4: Presentation Format

Use a standardized PowerPoint template with the modified fishbone as the central visual 1:

• Slide 1: Patient demographics and clinical summary
• Slide 2: Timeline of care with key decision points
• Slide 3: The fishbone diagram showing all contributing factors
• Slide 4: Classification (preventable/potentially preventable/non-preventable)
• Slide 5: Specific actionable recommendations

The presentation must be blame-free and system-focused 1. Frame discussions around "what happened" not "who did it."

Step 5: Documentation and Follow-Up

Document the following in standardized nomenclature 3:

• Cause of death classification: Cardiovascular vs. non-cardiovascular (when death is unclear or sudden, classify as cardiovascular) 7
• Timing: Periprocedural (≤30 days or during index hospitalization), early (>30 days to 1 year), or late (>1 year) 7
• Goals of Care discussions: Were they held? Were they documented? 3
• Specific system changes needed: Assign responsibility and timeline

High-Impact Focus Areas

Based on the evidence, prioritize analysis of:

• GI emergencies (24.1% of surgical deaths) 2
• Head injuries (18.4% of deaths) 2
• Advanced GI malignancies (17% of deaths) 2
• Sepsis convergence patterns (common in hospital-based mortality data) 8

Use thematic analysis across multiple cases to identify patterns—single case reviews miss systemic issues 3. Track metrics over time and provide frequent feedback to maintain improvement 3.

The fishbone methodology ensures that mortality review becomes a learning tool rather than a punitive exercise, with 165 diagnostic errors identified across 61 cases in one study demonstrating its comprehensive nature 4.