Adverse events serious enough to harm patients are occurring in U.S. hospitals at least ten times more often than previously measured, according to a report released Thursday in the journal Health Affairs.
Researchers went to three large hospitals in the U.S., all of which have well established patient safety detection systems already in place.
The study team then tested a newer, more expensive, and extensive event system called the Institute for Healthcare Improvement's "Global Trigger Tool," against two more common but less sensitive tools. Those two are the voluntary reporting method and the Agency for Healthcare Research and Quality's Patient Safety Indicator method.
The GTT detected 354 adverse events, while the AHRQ system found 35 and the voluntary method found only four.
All errors discovered were serious enough to require some intervention, says lead author of the report, David Classen, associate professor of medicine at the University of Utah in Salt Lake City.
"The point of all this is that we need to develop better tools to measure the safety of care that we deliver," he said. Classen adds that many hospitals think they're capturing the essence of medical errors, but in fact there's a lot more they need to know about pitfalls in the process of care. "It's a learning curve that a lot of places have to go through," he says.
In this study, the GTT did not distinguish between preventable and unavoidable errors, but Classen says that other studies suggest that errors between 40% and 60% of the adverse events captured by these tools are considered preventable.
The GTT caught many types of adverse events, from those considered extremely serious and lethal, to those that could be quickly averted. They include infections, venous thromboembolisms, pressure ulcers, device failures and falls.
Among less serious adverse events, for example, medication was required to reverse a problem the incident provoked, he explains. Among the most serious, intensive intervention was required to keep a patient from dying, or in the worst case, a patient actually died because of the adverse event.
According to the report, for the most severe errors, the IHI's GTT and the AHRQ systems each detected four adverse events that the voluntary system entirely missed. Among the least severe, the GTT caught 204 errors, AHRQ captured 23 but the hospital voluntary reporting system discovered none.
Currently, nearly all hospitals use these two adverse event detection systems that are far less extensive, specific or sensitive than the Global Trigger Tool, Classen says. They are:
• The voluntary system used by virtually all hospitals, when a nurse or other provider notices a problem, notifies someone about the incident, which provokes an investigation to determine whether the incident should be reported to authorities.
• The Agency for Healthcare Research and Quality's Patient Safety Indicators review, which encompasses more than the voluntary reporting system but less than the GTT. The AHRQ PSI looks only for certain codes in the medical records.
With the GTT, hospital employees such as nurses or pharmacists intensively review closed charts for codes, summaries, medications problems, lab results, operation reports or nursing notes to detect any clues that a mistake may have occurred. In this study, independent members of a team from the IHI, which contributed to the report, did the reviews.
"A trigger could be a notation indicating, for example, a medication stop order, an abnormal lab result, or use of an antidote medication," the authors wrote. An investigation would ensue.
Classen says that only about 2% of the hospitals in the country now use the GTT. That's because the method is time consuming, labor-intensive, and expensive, especially in the absence of well-developed electronic medical record systems, which the hospitals in this study all had, he says.
Classen explains that the AHRQ method fails in part because hospital staff who insert codes "are not necessarily highly trained clinical individuals," so if the adverse event is not well documented in the medical record, the AHRQ system can't find it. "If it's not obvious and apparent, they won't see it and even if it is, they may miss it," he says.
As an example, he explains, "if a patient has a side effect from a drug that requires an antidote to be ordered, the AHRQ system would miss it, but under the GTT, our reviewers would have picked it up."
Classen says the study findings did not surprise him "because I do work in hospitals all the time, and I see the use of these other approaches – which are much cheaper and easier to do – often seem to miss these problems."