Pharmacists play critical role in reducing medication discrepancies

May 30 2007

Involving pharmacists in obtaining and assessing a patient's medication history before elective surgery can significantly reduce medication discrepancies upon hospital admission.

The study is published in the May 28, 2007 issue of the Archives of Internal Medicine.

Led by Toronto General Hospital (TGH), University Health Network and the Leslie Dan Faculty of Pharmacy, University of Toronto, the study is the first randomized controlled trial of its kind to evaluate the effectiveness of a pre-surgical medication assessment by a pharmacist to reduce medication discrepancies after elective surgery.

“Reconciling a patient's home medication regimen with drugs prescribed in hospital is difficult. We're also seeing sicker patients who are being treated for multiple illnesses,” said Olavo Fernandes, lead researcher, Pharmacy Clinical Site Leader at TGH and Assistant Professor, Faculty of Pharmacy at the University of Toronto. “What this study clearly tells us is that involving pharmacists in the assessment of patients' home medications before surgery can reduce medication discrepancies in hospitals.”

Accessing a patient's complete and accurate home medication history before admission to hospital is a common challenge faced by health care providers. Upon hospital admission, previous studies have found that more than 54 per cent of patients admitted to hospitals had at least one unintended medication discrepancy (e.g. failure to reorder a medication) between their home medication regimen and admission orders. Studies have also found that 23 per cent of patients experience an adverse event after discharge with over 70 per cent related to medications. This “medication information gap” can lead to a higher risk of medication errors and adverse events.

Admission to hospital for surgery can be a critical, vulnerable moment for medication discrepancies. Pharmacists, nurses, surgeons and university researchers partnered together to develop a multidisciplinary practice model to prevent patient medication discrepancies after surgery. During a six-week period, 464 patients were randomly assigned to receive the “intervention” or “standard care.” The intervention involved pharmacists, working with nurses in the surgical pre-admission clinic, to interview and assess patients' home medication history. These assessments were used to support surgeon prescribing of patients' home medications with a postoperative home medication order form. If needed, the pharmacist would follow-up with the patient's community pharmacy or family physician to clarify their medication regimen to ensure accuracy. The standard care arm involved nurse-conducted home medication histories and surgeon-generated orders without preadmission pharmacist medication assessments and generation of the postoperative home medication order form.

The study found a 50 per cent reduction in medication discrepancies upon hospital admission after surgery (20.3 per cent of patients who had the intervention assessment had at least one postoperative medication discrepancy related to home medications compared with 40.2 per cent in the standard care arm). The most common medication discrepancy was the omission of reordering home medications. Furthermore, the potential clinical impact of these discrepancies was also assessed. Results demonstrated that 29.9 per cent of patients with standard care had at least one postoperative medication discrepancy with the potential to cause “possible” or “probably harm” compared with 12.9 per cent of those who were part of the intervention. Clinicians are optimistic they can reduce medication discrepancies even further with enhancements to the multidisciplinary model.

“We designed an intervention that saw a pharmacist join the assessment and focus on a more detailed medication information assessment,” said Jana Bajcar, Associate Professor, Faculty of Pharmacy and one of the study's authors. “Our goal was to strengthen the collaborative environment while increasing patient safety.”

“Ontario patients should have confidence that they are not only getting the best quality health care, but also the safest,” said George Smitherman, Minister of Health and Long-Term Care. “Congratulations to Toronto General Hospital and the University of Toronto's Faculty of Pharmacy for their breakthrough work in reducing medication discrepancies.”

The study involved “medication reconciliation” - one of six, targeted interventions that are part of a national patient safety campaign called Safer Healthcare Now! Medication reconciliation involves a systematic assessment of patients' medications at key interfaces of care (such as hospital admission and discharge) to identify and resolve discrepancies.

Toronto General Hospital is a member of University Health Network, along with the Toronto Western Hospital and the Princess Margaret Hospital. These research hospitals are affiliated with the University of Toronto. The scope of research at Toronto General Hospital has made this institution a national and international source for cardiovascular discovery, education and patient care, as well as for its innovations in transplantation, surgical innovation, infectious diseases, diabetes and genomic medicine. For more information, please visit