Although previous studies have found that about 20% of patients have some problem with their prescription medicine after discharge, the new study found errors more widespread.
"We found that approximately 50% of patients had either a potentially avoidable adverse drug event or some other problem with their medicine that had the potential to cause harm if left uncorrected," says researcher Sunil Kripalani, MD, associate professor of medicine at Vanderbilt University School of Medicine in Nashville.
Most errors were mild, he tells WebMD. Some were life-threatening, but no deaths were linked to the medication errors in the study.
The errors occurred even in patients who got extra counseling from a pharmacist, Kripalani says. However, certain people, such as those who had difficulty understanding health information, did tend to benefit from having that extra help, he says.
The study is published in the Annals of Internal Medicine.
Medication errors harm at least 1.5 million people a year in the U.S., according to the Institute of Medicine of the National Academies.
Medication Errors: Study Details
The researchers looked at how extra help from pharmacists might help reduce medication errors.
They were discharged from Vanderbilt University Hospital or Brigham and Women's Hospital in Boston.
The researchers assigned about half of the patients to get extra pharmacist help. They compared them to the other half, who got standard care.
In the extra-help group, pharmacists:
- Counseled patients in one or two sessions about how to reduce medication errors
- Evaluated how well the patient understood the medication instructions
- Asked about the patient's social support
- Provided pill boxes and illustrated medication schedules
- Called the patients one to four days after discharge to ask about any medication issues
Patients in the comparison group got information about medication from their doctor and hospital nurses when they were discharged.
The researchers tracked medication errors for a month after discharge.
Medication Errors: Study Results
Of the 851 patients, 432, or just over 50%, had one or more medication errors in the month after hospital discharge.
In the usual-care group, 407 ''clinically important'' medication errors were found, compared to 370 in the group that received additional counseling.
Of these, seven in each group were life threatening, although none proved fatal.
Most often involved in errors were:
- Heart disease drugs
- Opioids for pain
- Cholesterol drugs
- Herbs, vitamins, supplements
- Diabetes drugs
- Anti-clotting drugs
Some errors could have been avoided, the researchers say, by closer monitoring by doctors or pharmacists.
Common medication errors included:
- Missed or incorrect doses
- Stopping a medicine before instructed
- Not filling a prescription
- Taking a medicine less or more often than prescribed
Medication Errors: Discussion
Although the extra pharmacist help didn't reduce the overall medication errors, Kripalani says it seemed to help some.
"What our subgroup analysis hinted at is that patients with more complex medication regimens, those with low health literacy, patients who tend to have more trouble understanding and managing their health, and those who had cognitive problems, tended to benefit more," he says.
Kripalani is a consultant, too, and holds equity in PictureRx, which produces patient education materials. It had no role in the study.
Medication Errors: Pharmacists Weigh In
The 50% finding is surprising, says Allen Vaida, PharmD, executive vice president of the Institute for Safe Medication Practices. He reviewed the findings for WebMD.
The errors occurred, he points out, at hospitals with excellent programs to minimize medication errors.
"That should be a wakeup call," he says, reminding people that errors can happen even at top hospitals.
The study suggests that talking to patients about medicines only at the time of hospital discharge is not ideal, says Cynthia Reilly, a spokeswoman for the American Society of Health-System Pharmacists.
A growing trend among hospital pharmacists, she says, is to telephone patients after discharge, as those in the study did, to check up on medications.
"There is definitely that critical time frame -- say, the first 10 days after a patient is discharged -- when medication error is more likely," she tells WebMD.
Medication Errors: Tips for Patients
Although some of the errors could have been avoided with closer monitoring by health care professionals, patients can take steps, too, Kripalani says. He tells patients:
- Get your questions about medicines answered before leaving the hospital.
- Have a "lifeline" person to contact once you are home.
- Pay extra attention to medicines right after leaving the hospital. "We studied the first month [after discharge], but I would say the first week or two is the most vulnerable time," he says.
- Go to one pharmacy so a list of your medications are in one place.
- Develop a relationship with your pharmacist.
- Ask someone to be your advocate to help you.