Adverse drug events -- although sometimes difficult to detect, define, or classify -- remain a significant threat to patient safety in the U.S., according to a report by Chunliu Zhan, M.D., in the July issue of the Joint Commission Journal on Quality and Patient Safety released today.
Zhan calculated that 3.7 out of every 1,000 patient visits in the U.S. in 2001 were to treat adverse effects resulting from medication. That was up from 2.9 in 1995.
A staff fellow at the U.S. Agency for Healthcare Research and Quality, Zhan said he was writing the patient-safety chapter for the AHRQ's annual National Healthcare Quality Report when he noticed a general lack of data regarding adverse drug events, or ADEs, and what was available came mostly from voluntary reporting.
Zhan decided better statistics were needed. So, in collaboration with the National Center for Health Statistics, he mined data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey from 1995 to 2001.
From these sources, Zhan was able to find the number of patient visits to ambulatory physician offices, hospital outpatient departments and hospital emergency departments where adverse drug effects were coded as the cause of injury. In doing so, he coined a new term: "visits for treating adverse drug effects," or VADEs.
"This is first-time data," Zhan said. "One of the major objectives was to come up with new ways to measure adverse drug events."
The report notes how this is a "patient-centered, utilization-based" definition of ADEs and "eliminates arbitrariness in defining and detecting ADEs."
For the years studied, Zhan calculated that 11 to 15 VADEs were made for every 1,000 U.S. residents.
"If you look at 100 people in your neighborhood," Zhan said, "you'd have at least one person who had gone to see the doctor for an adverse drug effect."
For the years studied, the total number of VADEs ranged from approximately 1.98 million in 1997, to about 3.24 million in 2001.
The most common problems reported were dermatological symptoms, such as a rash (11.4%); gastrointestinal symptoms such as nausea and abdominal pain (8.2%); and dizziness (3.2%).
"Some of these symptoms may be a side effect and not an ADE," Zhan acknowledged. "It's a subtle issue."
The medications responsible for most of the adverse effects were antibiotics and other anti-infectives (18.5%) and hormones and synthetic substitutes (10.7%).
Although it found a new way to look at an old problem, the study does not offer much in the way of possible interventions, but Zhan said that wasn't its intent. The objective, he said, was to do an epidemiological study to assess the magnitude of the problem.
Interventions are a separate issue, he said. Since 1999 when the Institute of Medicine released its landmark report on medical errors, To Err is Human, Zhan said "the mainstream emphasis is to not blame the individual and to try to improve the system so individuals won't be able to make a mistake."
Despite this emphasis, a recent survey by the Huntingdon Valley, Pa.-based Institute for Safe Medical Practices found that healthcare professionals still fear they will be punished for medication errors.
"People are still afraid to report errors or disclose errors because they're afraid of getting reprimanded by their state licensing board," said ISMP Executive Director Allen Vaida. "There hasn't been, in our minds, enough culture change."
In its Feb. 24 newsletter, the ISMP asked healthcare professionals their opinions on the subject. In the May 19 issue of its Medication Safety Alert, the ISMP reported that 93% of 1,572 licensed nurses, physicians and pharmacists responding to the survey reported that they thought their licenses would be restricted in some manner if they were involved in a fatal medication error.
Also, 30% believed they would receive a verbal or written reprimand or they would be required to take remedial education even if the error never reached the patient.
Although To Err is Human advocated an end to healthcare's "shame and blame" culture, Vaida said this survey probably does not represent a step backward. Rather, he said it shows that healthcare had not advanced as far as previously thought.
He also stressed that a blame-free culture -- where people learn from mistakes -- should not be confused with a lack of accountability.
"We've always supported that everyone's accountable, but right now all the accountability is on the front-line practitioner and no one else is claiming responsibility," Vaida said. "What about two drugs with almost identical names or packaging? Where is the Food and Drug Administration on that? Or the drug manufacturers?
"It's overall accountability we want," he added. "Everyone in the system has to be accountable because this is how we make progress -- instead of one person being on the short end."
