The study found that 81 percent of 151 patients admitted to Canadian hospitals while on four or more different medications experienced at least one medical error by hospital personnel. More than a third of the errors were potentially harmful to the patient, the researchers said.
"Until we have an automated system in place that tracks prescriptions filled in Ontario, the best mechanism for finding stopping (drug mistakes) is for the patient or family member to say how they're using the medications at home," one of the study's leaders said.
Patients taking a high number of prescription medications who are then unexpectedly admitted to hospital face a medication error rate of more than 50 per cent with their existing medications, one-third of which could result in more serious complications, says a new study by University of Toronto researchers.
"In that kind of situation -- where a patient is taking quite a few medicines, is acutely ill and possibly cognitively impaired, it's very difficult to get an accurate medication use history.
The most common mistake is to be unaware that the patient is taking a particular medicine, and there is no mechanism that would clue you into a potential problem," notes Etchells, a professor of medicine at U of T, director of the Patient Safety Service at Sunnybrook and Women's College Health Sciences Centre and internal medicine physician at the hospital.
Of that number, 151 patients were included in their study: to be included patients had to be taking at least four prescription medicines at home and their admission to hospital was unplanned.
A member of the research team then conducted an interview with the patient or family and recorded a thorough medication history.
It was then determined whether there were any discrepancies between what the patient reported during the interview and the medications that were prescribed after admission.
"Until we have an automated system in place that tracks prescriptions filled in Ontario, the best mechanism for finding it out is for the patient or family member to say how they're using the medications at home," says Etchells, who was an author on the landmark nation-wide study examining adverse events in Canadian hospitals last May and is a leading Canadian expert in patient safety issues.