They found that in more than one in five cases, chain pharmacies made some type of error in filling their prescriptions.
"The results confirm our worst fears," said Dr. Ken Barker of Auburn University School of Pharmacy, one of the country's leading experts in studying pharmacy error rates. "There really is a problem out there."
The ABC test was designed and supervised by Auburn's Dr. Betsy Flynn, a specialist in studying errors in neighborhood pharmacies who designed a similar undercover test for ABC News over a decade ago.
"The 22 percent error rate found in the study was unacceptable," said Flynn, who expressed her "surprise and disappointment" that "despite all of the implementation of technology over the past 12 years, the error rate was similar to the previous study."
While in no case were ABC's producers given the wrong medication, there were a variety of dispensing errors found -- too many or too few pills, faulty and missing instructions on the labeling, even a failure to put a child proof cap on a powerful medicine for bi-polar disorder.
But perhaps the most important finding of the undercover test was a dramatic reduction in time spent on patient counseling by pharmacists.
Despite federal and state laws that require pharmacists to provide counseling to customers picking up new medications, patient counseling was only offered in 27 out of 100 purchases of new prescriptions, less than a third, in the ABC-Auburn Study.
Particularly alarming to the Auburn experts was the chain pharmacies' failure to warn patients of potentially harmful interactions when they purchased certain over-the-counter medications, such as adult strength aspirin with Coumadin, a blood thinner. In only eight cases out of 25 were the customers given a verbal warning.
Finally, the study revealed that some pharmacies appear to be misleading customers into signing away their right to patient counseling.
Although the ABC producers paid with cash and no insurance was involved, in most cases they were still asked to sign at the pharmacy counter to pick up their prescriptions. But with only a few exceptions, our producers were never told they were signing forms that also included language to waive the legal right to counseling with a pharmacist.
"They're deceiving the patient about what they're really signing," said Bruce Berger, a department head at Auburn's pharmacy school who says the pharmacy personnel at the counter may not know it, but they are in effect, undercutting the law.