Background: Previous studies of adverse drug events (ADE) as a cause of hos
pital admission in the elderly have often been limited in their ability to
assess fully the impact and potential for prevention because they either di
d not include all categories of ADE and/or did not assess severity and prev
entability.
Aims: To assess the frequency, severity and preventability of ADE causing e
mergency medical admissions in the elderly.
Methods: Cross-sectional survey of 219 patients aged 75 years and over who
were consecutive unplanned admissions to acute medical units of the Royal H
obart Hospital in an 8-week period during August and September 1998.
Results: Seventy-three of 240 (30.4%) admissions may have been a result of
ADE. Patients admitted because of ADE were taking more drugs than those adm
itted for other reasons. Most ADE were adverse drug reactions to a single (
46%) or multiple drugs (25%). Non-compliance, omission or cessation of indi
cated treatment accounted collectively for 26% of admissions. Of all ADE ad
missions 53.4% were considered definitely preventable. The commonest causat
ive drugs were cardiovascular drugs (48.4%), and the commonest manifestatio
ns were falls and postural hypotension (24.1%), heart failure (16.9%) and d
elirium (14.5%). ADE categories in which a high proportion of admissions wa
s both severe and definitely preventable were non-compliance and omission o
f indicated treatment.
Conclusions: Adverse drug events are a common preventable cause of unplanne
d medical admissions in the elderly. Non-compliance and omission of indicat
ed treatment are causes of ADE-related admissions that are both preventable
and frequently associated with severe ADE.