It's one of those statistics that would make most people feel uneasy: About 18 per cent of patients admitted to hospitals in industrialized countries suffer some kind of "adverse event" while in the care of the medical system.
They may be given an inappropriate medication, pick up an antibiotic-resistant infection or fall on the way to the toilet. Most hospital mishaps are minor and don't result in lasting harm. But in some cases the patient's life is cut short.
Health-care experts are well aware of these problems, and many medical institutions, including those in Canada, have been trying to minimize them.
But a study published this week in the New England Journal of Medicine reveals that reducing hospital errors is easier said than done.
The researchers focused their attention on 10 hospitals in North Carolina, a state that has embraced new programs designed to improve patient safety. They randomly selected 2,341 patient charts from the period between January, 2002, and December, 2007, to see if the ongoing safety efforts made a dent in the number of adverse events.
"We found that harm rates - in a state that was very engaged in patient safety - did not change over time. This was a little surprising to all of us," said the study's senior author, Paul Sharek, a professor at Stanford University and a physician at Lucile Packard Children's Hospital in California.
He expects many health-care observers will be disappointed by the results. Nonetheless, Dr. Sharek insisted in an interview, "our findings should not be interpreted as we can't make a difference, but rather large-scale patient safety improvement is challenging."
He remains convinced "it just takes time and resources" to implement meaningful change. Dr. Sharek points to the cost and complexity of introducing electronic patient records that should eventually help reduce medical errors.
There is also still a lot to be learned about safeguarding patients, he noted. Various medical bodies have established practice guidelines for infection control and other patient-care-related issues. But not all the recommendations have been put to rigorous scientific tests. "The evidence base is still relatively sparse in terms of proven best practices to decrease harm," Dr. Sharek says.
Despite the difficulties, the health-care system must keep trying to reduce adverse events, he said: It simply can't afford not to.