Error prevention: the seven barriers
Seven upright slats with small gaps cut at different heights; one arrow labeled ERROR threads through the aligned gaps to a bed, while a second arrow is stopped dead at the third slat.
The model
Errors reach a patient only when several defenses happen to line up wrong on the same shift. Safe practice is a stack of barriers, not a personality trait. The nurse is the last barrier in the stack. The nurse is never the only one, and a system that expects one person to catch everything is already broken.
The seven barriers
- Two patient identifiers — verified before every medication, specimen, procedure, and treatment.
- Read-back — every verbal or telephone order is written down, read back, and confirmed by the prescriber.
- Independent double check — a second qualified nurse verifies high-alert drugs separately, not by looking over a shoulder.
- Barcode scanning at the point of care — the patient's band is scanned at the bedside, not the cart.
- The pre-procedure time-out — everyone stops, and the team confirms patient, procedure, and site out loud.
- Medication reconciliation — performed at admission, at transfer, and at discharge, because transitions are where lists diverge.
- The escalation duty — the obligation to stop the line and speak up when something does not reconcile.
The identifier rule
Two identifiers, and neither one is the room number or the bed position. Full name, date of birth, and the medical record number qualify. Location does not, because location changes without anyone telling you.
Margin notethe last barrier is you, but never only you.
Watch outa workaround that saves time is the textbook definition of a latent failure. Taped-over sensors, pre-scanned bands, and pre-poured cups are barriers already removed.
Takeawayevery error question is asking which layer got skipped.
National Patient Safety Goals in full → BOOK 04 · P4. Documentation standards → BOOK 15 · P11.