'July Effect'

Study Identifies Spike in Fatal Medication Errors When New Residents Arrive

June 22, 2010 05:05 pm Barbara Bein

Fatal medication errors inside medical institutions spike in July, and the increase is at least partly associated with the arrival of new medical residents who are starting their responsibilities in patient care. That's the conclusion of researchers from the University of California, San Diego, who recommend increasing resident education about medications.

According to the study(springerlink.com), which was published online May 29 by the Journal of General Internal Medicine, fatal medication errors spiked as much as 10 percent in July inside medical institutions in U.S. counties that contain teaching hospitals. This spike is informally known as the "July Effect" or the "New Resident Hypothesis."

"We found a significant July spike in fatal medication errors inside medical institutions," said researchers in the department of sociology at the university. "After assessing competing explanations, we concluded that the July mortality spike results at least partly from changes associated with the arrival of new medical residents."

The researchers examined computerized death certificates from 1979-2006. They focused on inpatients, outpatients and those who died in the emergency department. Fatal medication errors were defined as those recorded as the primary cause of death.

According to the researchers, computerized death certificates do not record whether the patient died in a teaching hospital, but they do record the county of death. So they looked at the proportion of major teaching hospitals in each county.

The results were clear: "The greater the concentration of teaching hospitals in a region, the greater the July Effect for intra-institutional medication errors in that region," they found.

Three key themes emerged during the course of the study:

  • fatal medication errors spiked in July and in no other month;
  • the July spike appeared only in counties containing teaching hospitals; and
  • in these counties, July mortality from medication errors was 10 percent above the expected level.

According to the study, researchers entertained hypotheses other than that new residents contributed to the increase in fatal medication errors, including that the July Effect may result from patient behavioral changes during the summer, that it results from the July 4 holiday or that it results from coding changes in July.

They quickly discounted each of these alternatives, however.

For example, if the July Effect came from greater alcohol consumption in the summer that was associated with harmful alcohol-medication interactions, then the spike also would be seen in August. But no such August spike was found.

In addition, said the researchers, the July Effect does not result from the July 4 holiday because the holiday is celebrated across the country, and the effect is evident only in counties with teaching hospitals.

The researchers could not attribute the July Effect to coding changes, either, because no evidence shows that there are more misclassifications of causes of death in July than in any other month.

Although the researchers acknowledge that further studies are indicated to assess the validity of their findings, they said the study's results have implications for medical policy and provide fresh evidence for

  • re-evaluating responsibilities assigned to new residents,
  • increasing supervision of new residents and
  • increasing education about medication safety.

"Incorporating these changes might reduce both fatal and nonfatal medication errors and, thereby, reduce the substantial costs associated with medication errors," the researchers said.

AAFP Director Reid Blackwelder, M.D., of Kingsport, Tenn., agrees that more needs to be done to minimize medication errors. He is the residency director at East Tennessee State University, or ETSU, Family Physicians of Kingsport and professor of family medicine at ETSU's Quillen College of Medicine.

Blackwelder said he is not surprised that the July spike is being attributed to residents, but he noted that changes are occurring throughout the entire residency system during July.

"What people may not recognize is not just that there are new interns. Everybody in the system has moved up a year, and the most experienced residents have now graduated," he told AAFP News Now. "It truly is an overnight shift for many of us when our most experienced people disappear and, all of a sudden, even people in the residency for two years are in a new role.

"We have to recognize that all resident skills are different as of July 1."

Blackwelder concurred that physicians need more direct education about the use of medications, especially because many patients take numerous prescribed drugs, as well as various OTC medications. In addition, some may be using street drugs or prescription drugs they got from other people, he said.

The authors of the journal study did not address how the fatal medication errors occurred, but Blackwelder said the reasons for such errors are many and diverse, including whether too many medications overall were given, the medications given interacted adversely, the wrong drug was given for the wrong reason, or too many of the right drugs were given for the right reason.

According to Blackwelder, pharmacological education efforts are not routinely available in residencies. "The education on pharmacology that medical students get really does not prepare them for handling the realities of prescribing as a physician," he noted.