Using Two Patient Identifiers in the Pharmacy for Safety: How It Prevents Medication Errors

Every year, thousands of people in the U.S. receive the wrong medication because a pharmacist mixed up their name with someone else’s. It’s not because someone was careless-it’s often because the system didn’t make it easy to get it right. The fix? Using two patient identifiers before handing out any prescription. This isn’t just a best practice. It’s a federal safety requirement. And when done right, it stops errors before they happen.

Why Two Identifiers? The Real Reason It Matters

Think about how many people share the same first name. How many patients named John Smith walk into your local pharmacy? Now imagine one of them has a life-threatening allergy to penicillin. Another takes blood thinners. If you only check the name, you could hand the wrong person the wrong pill-and there’s no second chance.

The Joint Commission, the group that accredits U.S. hospitals and pharmacies, made this rule official in 2003. Their National Patient Safety Goal (NPSG.01.01.01) says: Never rely on a single identifier. You must use two. Not one. Not sometimes. Always.

Acceptable identifiers include:

• Full legal name
• Date of birth
• Assigned medical record number
• Phone number
• Address (in some cases, if unique)

What’s not allowed? Room number. Bed number. Location. These change. They’re not tied to the person. Using them is like checking a license plate instead of a driver’s name-it’s not reliable.

What Happens When You Skip This Step

A 2020 study in JMIR Medical Informatics found that up to 10% of serious drug interaction alerts in U.S. pharmacies go unnoticed-not because the system missed them, but because the patient’s record was split across two different files. One file had the allergy. The other had the prescription. The pharmacist never saw both.

That’s not theory. That’s real life. In a documented case from 2023, a patient was brought to the ER unconscious. The hospital couldn’t find his record because he was registered under his middle name. He had a known allergy to morphine. The team gave him morphine anyway. He nearly died.

This isn’t rare. The Emergency Care Research Institute (ECRI) lists patient misidentification as one of the top 10 threats to safety every year. In 2023, they reported that 6,000 patients annually receive contraindicated drugs because of broken identification systems. That’s 6,000 preventable emergencies.

Manual Verification Alone Isn’t Enough

Many pharmacies still rely on pharmacists asking patients: “What’s your name?” and “When were you born?” Then they check it against the screen. Sounds simple. But humans make mistakes. Especially under pressure.

A 2023 survey by the American Society of Health-System Pharmacists (ASHP) found that 63% of pharmacists admitted to cutting corners during busy hours. Some skip writing down the verification. Others only ask one question. One community pharmacist on Reddit said: “I’ve seen techs verify names but not DOBs because the line was out the door.”

And here’s the problem: even when two people double-check, it doesn’t help much. A 2020 review in BMJ Quality & Safety found no strong evidence that having two staff members verify a medication reduces errors. Why? Because if both are looking at the same screen, they both see the same mistake. Independent verification only works if each person checks from a different source.

Technology Makes It Work

The most effective way to use two identifiers isn’t by asking. It’s by scanning.

Barcode systems linked to patient wristbands cut medication errors by 75%, according to a 2012 study in the Journal of Patient Safety. Here’s how it works:

1. The pharmacist scans the patient’s wristband (contains name and DOB).
2. The system checks the medication against the patient’s profile.
3. If there’s a mismatch-like a drug allergy or wrong dose-the system flashes a warning.

In one hospital, this system generated 38 error alerts per million doses administered. That sounds high. But it’s actually good. Before the system, errors were going unnoticed. Now, they’re caught.

Biometric systems like palm-vein scanners are even faster. Imprivata’s system matches patients to their records 94% of the time. Without it? Only 17%. That’s a five-fold improvement.

And it’s not just for hospitals. Community pharmacies using barcode scanners reported a 60% drop in near-miss errors within six months.

Why EMPI Systems Are the Hidden Backbone

Here’s a dirty secret: many pharmacies don’t have one patient record. They have three. Or five. Or ten.

Why? Because patients visit different clinics, get registered under slightly different names, or use nicknames. One John Smith might be “John A. Smith” in the ER, “J. Smith” in the pharmacy, and “John” in the lab. The system doesn’t know they’re the same person.

That’s where an Enterprise Master Patient Index (EMPI) comes in. It’s a central database that links all records under one unique ID. Think of it like a social security number for your medical history.

Hospitals with EMPI systems reduce duplicate records by up to 80%. Without them, 8-12% of patient records are duplicated. That’s not just messy. It’s deadly. One duplicate record can mean a patient gets double the dose. Or a drug they’re allergic to.

The 21st Century Cures Act and CMS rules now require health systems to fix this. Why? Because you can’t share data safely if you don’t know who the data belongs to.

What Gets Documented-and What Doesn’t

Verifying two identifiers isn’t enough. You have to prove you did it.

The Joint Commission found that in 37% of non-compliant pharmacies, staff didn’t document the verification at all. No note. No signature. No timestamp. That’s a problem during inspections.

Good documentation means:

• Recording both identifiers used
• Noting the time and person who verified
• Linking it to the specific medication dispensed

Electronic systems do this automatically. Paper charts? They get lost. Or filled out after the fact.

Barriers and How to Overcome Them

Not every pharmacy has scanners. Not every patient can speak. Not every system talks to the other.

Here’s how to fix common problems:

• Patients who can’t respond: Use a family member, guardian, or ID bracelet. If none exist, use the medical record number + date of birth and document the reason.
• Similar names: Use EMPI to flag duplicates. Train staff to pause if two patients have the same name and birth year.
• Staff resistance: Show them the data. One pharmacy cut its error rate in half after installing scanners. That’s fewer calls from angry patients. Fewer lawsuits. Fewer sleepless nights.
• Time crunch: Biometric scanners take under 10 seconds. Barcodes take 15. Manual check? 30 seconds-plus the time to write it down.

What’s Next? The Push for a National ID

The Office of the National Coordinator for Health IT (ONC) launched a pilot in January 2025 to test a voluntary national patient identifier. It’s not mandatory yet. But it’s coming.

Why? Because without one, we’re stuck with patchwork systems. A patient in Seattle might have five different records. One in Chicago might have three. When they’re admitted to a hospital out of state? The system can’t find them.

A 2024 study showed that using a unique identifier could uncover up to 9.7% more dangerous drug interactions. That’s not just better data. It’s saved lives.

Bottom Line: It’s Not Optional

Using two patient identifiers isn’t a checklist item. It’s a lifeline. Every time you skip it, you’re gambling with someone’s health. And the odds aren’t good.

The data is clear:

• 75% fewer errors with barcode systems
• 94% accuracy with biometrics
• 6,000 patients harmed each year without it
• 37% of pharmacies fail to document verification

If your pharmacy doesn’t use technology to support two-identifier verification, you’re relying on memory, speed, and luck. That’s not safety. That’s risk.

The fix isn’t expensive. It’s simple. Scan. Verify. Document. Repeat. Every time. No exceptions.