Studies evaluate criteria for detecting potentially inappropriate medications in older hospitalized patients

According to information in the article, adverse drug events (ADEs) are a significant issue in the older population, and are thought to represent an important cause of hospitalization and account for substantial health care expenditures. Some ADEs are associated with potentially inappropriate medications (PIMs): agents that may cause problems in older patients "because of the higher risk of intolerance related to adverse pharmacodynamics or pharmacokinetics or drug-disease interactions." During the last two decades, the Beers criteria for judging whether a medication is appropriate for use in an older patient have become the leading standard. Nevertheless, the authors write, research into whether the Beers criteria are associated with avoidable ADEs has not generated consistent results.

Hilary Hamilton, M.B., M.R.C.P.I., and colleagues from University College Cork in Ireland had developed STOPP as an alternate way to address the PIMs in older patients. In this study, they compared STOPP and the Beers criteria in terms of the prevalence of ADEs associated with PIMs, including those resulting in hospital admission. Their prospective study included 600 consecutive patients ages 65 years or older admitted to a university hospital. The researchers examined the patient's preadmission medication regimens and clinical profile, then applied the STOPP and Beers criteria to determine whether any agents were PIMs. The only ADEs noted were those that occurred after exposure to PIMs but before hospital management. Incidents were analyzed for ADEs against World Health Organization-Uppsala Monitoring Centre criteria, and ADE avoidability against Hallas criteria.

A total of 329 ADEs were detected in 158 of the 600 patients. Of those, 219 ADEs were determined to have played a part in the patient's admission to the hospital; 68.9 percent (151) of these were determined to be avoidable or potentially avoidable. When STOPP criteria were applied, researchers found that serious, avoidable ADEs were identified more often (170 ADEs, or 51.7 percent) than when Beers criteria (67 ADEs, or 20.4 percent) were applied.

According to the authors, the results suggest that STOPP criteria were more likely than Beers criteria to reveal ADEs in general, avoidable or potentially avoidable ADEs, and ADEs that may have factored into the patient's hospitalization. "We believe that this finding strengthens the argument for the use of STOPP criteria in everyday clinical practice as a means of reducing the risk of ADEs in older patient," they write. In addition to calling for further research, the authors state, "Given the current data showing that PIMs are clinically significant in relation to ADEs, application of the STOPP criteria to drug prescribing and dispensing in older people could be highly valuable as a routine screening tool."

Research Letter: Where Older Patients Receive Inappropriate Medications

Hospital staff may exacerbate the prevalence of PIMs and actually inappropriate medications (AIMs), according to a research letter that is also part of the Less Is More series.

Alessandro Morandi, M.D., from the Vanderbilt University School of Medicine in Nashville, and colleagues designed a prospective cohort study of patients ages 60 years and older who spent time in the intensive care unit (ICU) of an academic hospital. Researchers studied medication prescription at five points: preadmission, admission to a ward, admission to the ICU, discharge from the ICU, and discharge from the hospital. They used the Beers criteria to judge whether drugs were PIMs, and a clinical panel to determine which PIMs were AIMs.

Before admission to the hospital, 66 percent of patients had at least one PIM; by the time they were discharged, 85 percent did. Half of the PIMs detected at hospital discharge were originally prescribed in the ICU. A majority (59 percent) of patients with at least one PIM also had at least one AIM. Of the AIMs, 59 percent were first prescribed in the ICU.

"Our study highlights the importance of performing an evaluation of medication appropriateness during reconciliation of medications at hospital admission, ICU discharge, and hospital discharge," write the authors. "Given the high prevalence of PIMs and AIMs among elderly survivors of critical illness, physicians practicing in the ICU and hospital wards should be more attentive to the appropriateness of continuing medication therapies started in the ICU. Better coordination is needed at this transition point, with attention to the rationale for starting each medication therapy in the ICU and discussion of when it can be stopped."

Commentary: Improving Medication Safety

A commentary accompanying these articles points out that adverse drug events are not rare, and clinicians should strive for patient safety when prescribing. But the issue reaches beyond the individual prescriber and in many cases, systemwide reforms are needed. "By far the biggest problem is the lack of implementation of those tools already shown to be effective" in reducing ADEs, writes Jeffrey L. Schnipper, M.D., M.P.H., F.H.M., from Brigham and Women's Hospital in Boston.

He advocates taking current knowledge about medication safety interventions and incorporating it into "existing decision support within electronic prescribing and outpatient pharmacy systems." For example, writes Schnipper, technology that can detect PIMs may help clinicians decide when a patient's medication regimen should be adjusted. More research into effective methods of intervening is needed, he concludes: "… we need to focus our research on how to successfully implement multifaceted interventions in real health care settings so that gains in medication safety can be widely and successfully spread."