According to an Institute of Medicine report, more than 7,000 hospital deaths each year are related to medications. Since this report came out in 1999, there has been a heightened focus on improving medication safety and reducing the number of medication errors.

A hospital patient’s medication order list is first generated upon admission, when a physician, or other hospital personnel, takes a medication use history as part of the admitting process. Several factors can affect the accuracy of this report, including communication barriers, the patient’s own familiarity with his or her medications, and the time available for this interview. Previous research suggests discrepancies between the patient’s usual medications and what the physician orders are common. These discrepancies, if unintended, represent errors and can sometimes result in serious adverse events.

A new study in the February 28, 2005 issue of the Archives of Internal Medicine set out to identify unintended discrepancies between admission medication orders and medication use histories and evaluate the potential consequences of these discrepancies. The authors concluded that medication errors at the time of hospital admission are common, with some having the potential to cause harm.

About the Study

For this study, researchers reviewed the charts of all patients admitted to the general internal medicine unit of a teaching hospital at the University of Toronto over a three-month period in 2003. Patients were included if they reported using at least four regular prescription medications before admission. Out of 523 patients, 151 (29%) qualified for the study. The average age of these patients was 77, and the majority (59%) were women.

After a patient was admitted, the researchers allowed 48 hours for clarification of medication orders and to allow for the usual care process to take care of any problems during admission (e.g., the pharmacist having to clarify an unclear medication order). After this point, members of the research team visited the patients to conduct a thorough medication use history. To complete their report they relied on one or all of the following: patient or caregiver interview, inspection of prescription vials, and communication with a community pharmacy.

The researchers defined a medication discrepancy as any difference between a patient’s usual medications and the admission medication orders. They then asked the medical team to identify whether discrepancies were intended or unintended. Unintended discrepancies were classified into one of three categories depending on their potential to cause harm.

The Findings

Overall, 81 patients (54%) had at least one unintended discrepancy between the admission medication orders and their usual medication. Among these 81 patients there were 140 unintended discrepancies. The most common error was the omission of a regularly used medication, followed by a discrepancy in dose, a discrepancy in frequency, and the ordering of an incorrect drug.

Although the researchers classified most discrepancies (61%) as unlikely to cause harm, they classified 33% as having the potential to cause moderate discomfort or clinical deterioration, and 6% as having the potential to cause severe discomfort or clinical deterioration.

How Does This Affect You?

These results build upon previous research showing that medication errors are common at the time of hospital admission. This suggests that the current system for recording medication histories upon hospital admission is insufficient and needs to be revised to prevent potentially dangerous medication errors.

The authors note that a limitation of their study is the absence of a gold standard for the identification of home medication use. Current methods for completing a patient’s medication history rely on patient and family member interviews, examination of prescription vials if available, and if necessary, follow-up with the community pharmacy, making it difficult to design a foolproof process. As the use of technology to store and transfer medical information becomes more widespread, it is likely that this process will become more refined and reliable.

Although many medical errors are unfortunately beyond patients’ control, in the event of a hospital admission you can help insure that your medication orders start off correctly. If you take prescription medications on a regular basis, and especially if you take more than three different kinds, make sure you, and a family member or caregiver, are well versed in the different medications you take, including dosage and frequency. And, for elective admission, always be sure to bring your medication vials with you to the hospital.