Objectives
Potentially inappropriate prescribing in older adults is a problem that is well documented in the literature and has been associated with serious adverse drug reactions, hospitalization, and significant morbidity and mortality. Clinical support for the identification of potentially inappropriate medications and potential prescribing omissions is a priority for many clinicians in the primary care setting. The purpose of this research was to characterize the extent of potentially inappropriate prescribing, as defined by the STOPP/START criteria (Screening Tool for Older Persons potentially inappropriate Prescriptions, Screening Tool to Alert doctors to the Right Treatment), in the primary care setting.

Methods
A retrospective, observational chart review of older patients (>65 years) was conducted in a single primary care practice in Prince George, British Columbia, Canada. STOPP/START criteria were applied to patient charts, and the number of Potentially Inappropriate Medications (PIMs) and Potential Prescribing Omissions (PPOs) were recorded for each category.

Results
A randomized convenience sample of 100 patient charts was reviewed. 38% of patient charts had at least 1 PIM, with an average of 0.5 PIMs per chart. 76% of patient charts had at least one PPO. When excluding START criteria relating to vaccinations, 35% of patients had at least one PPO with an average of 0.6 PPOs per chart.

Conclusion
Elderly patients are at risk of adverse events secondary to sub-optimal prescribing. The STOPP/START criteria may be a useful tool to flag medications that require clinician follow-up and assessment. Problem medications/classes identified in this study (e.g. benzodiazepines and other medications predisposing persons to falls) may be good targets for future quality improvement strategies.