Background Beers criteria (BC) were developed in 1997 and updated in 2003, 2012 and 2015.

Purpose To evaluate the impact of BC updates in detection of potentially inappropriate medicines (PIM).

Material and methods This was a prospective study (February–March 2016) in patients ≥65 years admitted to the internal medicine unit. Studied variables: sex, age and prescribed drugs. PIM frequency was analysed according to 2003, 2012 and 2015 BC classified as: avoid drug (AD), avoid in specific pathology (ASP), use with caution (UC), interaction (I) and avoid according to renal function (ARF). Data sources: emergency reports and electronic prescription.

Results 60 patients were included (56.7% men), mean age 83.3 years, mean drugs per patient 8.58. According to 2003 BC, 20% of patients had PIM compared with 71.7% and 91.7% according to 2012 and 2015 BC. Mean PIM per patient: 0.25 (range 0–2), 1.67 (range 0–7) and 3.05 (range 0–10) according to 2003, 2012 and 2015 BC, respectively (p=0.00). 2003 BC: 15 PIM, 67% AD and 33% ASP. Most common 2003 BC was use of amiodarone (20% of PIM), followed by long term benzodiazepine use (13.3%), and use of antiplatelets or NSAIDs in anticoagulated patients (13.3%). 2012 BC: 100 PIM, 49% AD, 26% ASP and 25% UC. Most common 2012 BC was benzodiazepine use (22%), followed by use of drugs to avoid in dementia or cognitive impairment (12%) and antipsychotic use (10%). 2015 BC: 182 PIM, 47% AD, 35% UC, 14% ASP, 2% I and 2% ARF. Most common 2015 BC was diuretic use (22%), followed by proton pump inhibitor (PPI) use without indication (21%), and benzodiazepine use (12%).

Conclusion Number of PIM and mean PIM per patient increased with each update of BC, suggesting that sensitivity has increased and become more applicable to our environment. The withdrawal of some criteria, according to evidence updates, means that frequent PIM according to 2003 BC, such as the use of amiodarone or antiplatelet therapy in anticoagulated patients, are not present in subsequent revisions. Likewise, other PPIs that were not present in 2003 and 2012 BC, became habitual, such as the use of PPIs without indication, added in 2015, with widespread use in our environment.

References and/or acknowledgements Beers criteria.

No conflict of interest