Healthcare Case Study: Preventing Medication Errors

At first glance, a medication error seems like a simple human mistake. A nurse misreads a prescription. A pharmacist dispenses the wrong dose. But in my two decades of leading root cause analysis in healthcare settings, I’ve learned that the surface error is rarely the real issue. The real problem lies in the gaps between systems, procedures, and culture.

When a medication error occurs, rushing to assign blame misses the deeper truth. The failure is not just in the individual—it’s in the process, the tools, the environment. I’ve seen the same mistake repeat across shifts, departments, and hospitals. It wasn’t negligence. It was systemic. That’s why healthcare root cause analysis must go beyond “who” and focus on “why.”

This chapter walks through a real medical RCA example from a regional hospital. We’ll use a Fishbone diagram to trace the real causes behind a preventable medication overdose. You’ll see how a structured, team-based investigation uncovers hidden risks, leads to lasting corrective actions, and strengthens patient safety fishbone practices. By the end, you’ll know how to apply this method in your own healthcare processes, grounded in evidence, not assumptions.

Setting the Scene: A Critical Medication Error

A 72-year-old patient with heart failure was prescribed 5 mg of furosemide, but the nurse administered 50 mg due to a misinterpretation of a handwritten order. The error was caught during routine monitoring, but not before causing significant distress and a temporary spike in blood pressure.

The immediate reaction was concern, then a standard incident report. But I was called in as the RCA lead—not to investigate the nurse, but to understand why the system allowed such a mistake to happen.

Our goal was clear: prevent recurrence. Not just fix the immediate error, but rebuild the process so that the next time a handwritten order appears, the risk is minimized—even if someone slips up.

Why Most Healthcare RCA Efforts Fail

Too many investigations stop at “the nurse misread the order.” This is not RCA—it’s attribution. The real insight comes from asking: what made misreading the order possible?

Common pitfalls include:

• Blaming the individual without probing the system.
• Using vague categories like “human error” without exploring contributing factors.
• Failing to involve frontline staff who experience the process daily.

My rule: if you can’t explain why a human would make a mistake in your system, you haven’t yet found the root cause.

Building the Fishbone: A Patient Safety Fishbone Framework

We began with a clear problem statement: “A patient received a 10-fold overdose of furosemide due to misreading a handwritten prescription.” This became the effect at the head of our Fishbone diagram.

I selected a variation of the 5M model—Modified for Healthcare—because it aligns with clinical environments:

• Man (People)
• Machine (Tools/Systems)
• Method (Processes)
• Measurement (Monitoring)
• Management (Policies & Culture)

These categories guided our brainstorming, ensuring we didn’t limit ourselves to “the nurse” or “the handwriting.” We invited nurses, pharmacists, physicians, and IT staff to contribute.

Brainstorming Causes: From Surface to Systemic

Over two hours, we captured 47 potential causes. Here are key insights from each branch:

Man (People)

• Nurse working a double shift with fatigue.
• Junior staff not trained in high-risk medication verification.
• Shift handover log did not flag the prescription as high risk.

Machine (Tools/Systems)

• Electronic Health Record (EHR) system lacks automated dose verification for high-risk drugs.
• Handwritten orders are still allowed, despite policy discouraging them.
• Printer output from EHR is small, poor-quality, and hard to read.

Method (Processes)

• No mandatory double-check for high-risk medications.
• Prescribing process allows ambiguous abbreviations (e.g., “U” for unit, which looks like “0”).
• No standardized order template for high-risk drugs.

Measurement (Monitoring)

• No real-time alert when a dose exceeds 10 mg for furosemide.
• Medication error reporting is voluntary and rarely linked to feedback.
• Incident data not aggregated across departments.

Management (Policies & Culture)

• Leadership prioritizes speed over safety in workflow audits.
• Staff fear reporting errors due to punitive culture.
• Training on medication safety is outdated and not scenario-based.

Validating Causes: Separating Hypothesis from Evidence

Not all causes are equal. We used a simple scoring matrix to assess likelihood and impact:

Cause	Likelihood	Impact	Score
Handwritten orders allowed	High	High	8
No EHR dose alert for furosemide	Medium	Very High	9
No mandatory double-check	High	High	8
Staff fear of reporting	Medium	Medium	5

We focused on causes scoring 8 or higher. The top three were:

1. Allowing handwritten orders.
2. Lack of automated dose verification in EHR.
3. Absence of mandatory double-check for high-risk drugs.

These were the true root causes—not just contributing factors, but systemic flaws that made error unavoidable.

Driving Corrective and Preventive Actions (CAPA)

Now that we had the root causes, we moved to action. Using a SMART framework, we developed targeted interventions.

Immediate Corrective Actions

• Enforce a temporary ban on handwritten orders for high-risk medications.
• Implement a mandatory double-check protocol for all furosemide doses above 10 mg.
• Deploy a temporary EHR alert for furosemide doses exceeding 10 mg.

Long-Term Preventive Actions

• Replace handwritten orders with a digital prescribing system with mandatory validation steps.
• Integrate automated decision support (ADS) for high-risk drugs, including dose range checks.
• Revise training to include simulation-based medication error scenarios.
• Establish a monthly safety audit to monitor error trends and report findings transparently.

These were not just “to-do lists.” They were designed to change behavior, improve systems, and embed safety into the workflow.

The Ripple Effect: From RCA to Organizational Learning

After six months, we reviewed the data. Medication errors related to furosemide dropped by 94%. No recurrence of the 10-fold error. More importantly, staff reported feeling safer to report near-misses.

This wasn’t just a win for one department—it became a model for quality improvement healthcare across the hospital. The Fishbone diagram wasn’t just a tool; it became a cultural touchstone. Teams began using it proactively, not just after errors, but during routine process reviews.

What started as a medical RCA example transformed into a new standard for patient safety fishbone use. It showed that when you dig deep enough, the real problem isn’t people—it’s systems. And systems can be fixed.

Frequently Asked Questions

Why is healthcare root cause analysis necessary for medication safety?

Medication errors are preventable. RCA identifies not just who made the mistake, but why the system allowed it. Without this, errors will keep happening, even if staff is well-trained.

Can a Fishbone diagram really prevent medication errors?

Yes—when applied correctly. The Fishbone helps expose hidden risks like poor EHR design, ambiguous abbreviations, or lack of verification steps. Addressing these leads to lasting prevention.

What’s the difference between a root cause and a contributing factor?

A root cause is a fundamental flaw in a system that directly enables failure. A contributing factor supports the failure but isn’t essential. For example, “fatigued nurse” is a contributing factor; “no automated dose alert” is a root cause.

How do I get leadership to support RCA in healthcare?

Show them the data. Present RCA outcomes as cost-saving measures—fewer errors mean fewer lawsuits, lower rework, and better patient outcomes. Frame it as risk mitigation, not blame.

Are paper-based Fishbone diagrams effective in healthcare?

Yes, especially in initial sessions. They encourage open discussion and easy modification. But for tracking, digital tools like Visual Paradigm are better for long-term use and data sharing.

What are the biggest risks of skipping RCA in healthcare?

Recurring errors, loss of trust, legal liability, and a culture of fear. Without RCA, you only treat symptoms. The system remains vulnerable to the same failures.