A newly published study found Nova Scotia's pharmacies made nearly 100,000 medication errors between October 2010 and June 2017, including hundreds that harmed patients and, in two cases, caused or hastened death.

The study, published Tuesday in the online journal CMAJ Open, tracked reports from 301 community pharmacies collected by the province's Community Pharmacy Incident Reporting system.

Beverly Zwicker, registrar of the Nova Scotia College of Pharmacists, said the errors represent a tiny fraction of the more than 91 million prescriptions pharmacists dispensed in that period of time.

Still, she said the college is looking to improve on those numbers.

"Our goal is to get to zero," she said.

Most mistakes caught

The study looked at 98,097 errors or "quality-related events." While some errors reached the patient, the vast majority were described as "near misses" that were intercepted before the prescription was dispensed.

"Incorrect dose or frequency, incorrect quantity and incorrect drug were the most common types of quality-related events reported," said the study.

"Most of the quality-related events occurred at order entry, followed by preparation and dispensing, and prescribing."

Between October 2010 and June 2017, more than 80 percent of mistakes — 80,488 — were caught before drugs were issued to patients.

Still, there were 928 mistakes that caused harm to patients, including seven severe cases and two deaths.

"There are those that caused harm," said Zwicker. "And that's the driver for why we continue to be engaged in the process."

Adverse reactions

The study found adverse drug reactions were the mistake with the highest likelihood of harm.

Zwicker said those reactions could be as minor as an allergic rash caused by a sulfa drug, up to more serious consequences.

Bev Zwicker, registrar with the Nova Scotia College of Pharmacists, says her profession aims for an error rate of zero. (CBC)

"To be honest, that concerns me," she said.

"Is it a matter of we didn't have the information we needed, and if we had, we could have prevented those? Then that's troubling. That's something that we need to get at."

She said the key to prevention is often better communication among pharmacists, doctors and patients.

Zwicker noted that when a prescription error doesn't reach a patient, there's no onus on pharmacies to report them.

"To see that large number being reported really reflects on the understanding of Nova Scotia pharmacists and pharmacy technicians of the importance of reporting and learning from all errors. And I think that's good news," she said.