Background: Poisoning continues to be an important public health problem in
the US. In 1995, 2 million human poison exposures were reported to all poi
son centers in the US. Hospital emergency department data may be used to ex
amine the most critical nonfatal poisoning exposures. Methods: Data from th
e 1993-1996 National Hospital Ambulatory Medical Care Survey, which is a na
tional probability sample survey of visits to emergency departments of nonF
ederal, short-stay, and general hospitals, were examined to describe poison
ing-related emergency department visits in the US. Results: During 1993-199
6, the average annual number of emergency department visits was 93 million,
of which 37 million were injury related and 1 million were poisoning relat
ed. Children under 5 years of age had a significantly higher average annual
rate of poisoning-related visits (84 visits per 10,000 persons) than perso
ns 5-19 years of age and persons 35 years of age and over. "Poisoning by ot
her and unspecified drugs and medicinal substances" was the leading diagnos
is and was recorded at 21% of all poisoning-related visits. Poisoning-relat
ed visits were more often recorded as urgent (75%) and were more likely to
result in hospital admission (22%) compared to illness visits (45% and 17%,
respectively) and nonpoisoning-related injury visits (47% and 6%, respecti
vely). Conclusions: Poisoning-related injury visits comprise a small (1%),
but important component of the health care provided in emergency department
s. An examination of different definitions of poisoning revealed that for e
mergency department data, it is most appropriate to use the poisoning E-cod
es from the injury data framework developed by the injury control community
. Data from emergency departments are needed to monitor any changing patter
ns of nonfatal poisonings and to provide guidance for effective poison prev
ention programs.