Adverse event is a term that describes an unwanted drug side effect whether it was intended or accidental. Studies have shown that the more medications a patient takes – the greater the chance for an adverse event or drug interaction.

A clinical trail published in the March, 2003 Journal of the American Medical Association (JAMA) evaluated 1,523 adverse drug events over 12-month period from Medicare aged patients. Warfarin adverse events were discovered to be one of the most frequent mentioned. The study evaluated not only the frequency of adverse events but also studied those preventable vs. non-preventable events.

Investigators found an expected age-associated relationship with the number of medications Medicare patients take.

Of considerable interest to patients and care providers was the relationship between preventable vs. non-preventable serious adverse events. The data suggests that patient education and clear patient instruction can play a role in improving patient outcomes.

Specifically, adverse events associated with anticoagulants - including warfarin - accounted for 7.9% of the 1,523 events evaluated. Of the 121 anticoagulant adverse events – 43 (10.2%) were deemed “preventable”. The most frequent error in the preventable category occurred in the “wrong drug/wrong therapeutic choice”. Wrong drug or wrong therapeutic choice occurred 27.1% of patients followed closely by incorrect dosing errors. Inadequate patient education was responsible for 18% of preventable adverse events. _{[JAMA, p.1113]}

“If the findings of the present study are generalized to the population of all Medicare enrollees, then more than 1,900,000 adverse drug events – more than a quarter of which are preventable – occur each year among 38 million Medicare enrollees; furthermore, estimates based on our study suggest that there are in excess of 180,000 life-threatening or fatal adverse drug events per year, of which more than 50% may be preventable. For a number of reasons, these estimates are likely to be conservative.” _{[JAMA, p.1114]}

Quality Assured Services, Inc. is developing comprehensive, practical education materials for patients taking warfarin. Check back with us shortly and look for an upcoming feature article introducing new patient education from PTINR.com.