Incidence, severity and preventability of medication-related visits to the emergency department: a prospective study.
BACKGROUND
Medication-related visits to the emergency department are an important but poorly understood phenomenon. We sought to evaluate the frequency, severity and preventability of drug-related visits to the emergency department.


METHODS
We performed a prospective observational study of randomly selected adults presenting to the emergency department over a 12-week period. Emergency department visits were identified as drug-related on the basis of assessment by a pharmacist research assistant and an emergency physician; discrepancies were adjudicated by 2 independent reviewers.


RESULTS
Among the 1017 patients included in the study, the emergency department visit was identified as drug-related for 122 patients (12.0%, 95% confidence interval [CI] 10.1%-14.2%); of these, 83 visits (68.0%, 95% CI 59.0%-76.2%) were deemed preventable. Severity was classified as mild in 15.6% of the 122 cases, moderate in 74.6% and severe in 9.8%. The most common reasons for drug-related visits were adverse drug reactions (39.3%), nonadherence (27.9%) and use of the wrong or suboptimal drug (11.5%). The probability of admission was significantly higher among patients who had a drug-related visit than among those whose visit was not drug-related (OR 2.18, 95% CI 1.46-3.27, p < 0.001), and among those admitted, the median length of stay was longer (8.0 [interquartile range 23.5] v. 5.5 [interquartile range 10.0] days, p = 0.06).


CONCLUSIONS
More than 1 in 9 emergency department visits are due to drug-related adverse events, a potentially preventable problem in our health care system.
Department of Pharmacy, Queen Elizabeth II Health Sciences Centre, Capital Health, Halifax, NS. peter.zed@dal.ca
Peter J
PJ
Zed
Riyad B
RB
Abu-Laban
Robert M
RM
Balen
Peter S
PS
Loewen
Corinne M
CM
Hohl
Jeffrey R
JR
Brubacher
Kerry
K
Wilbur
Matthew O
MO
Wiens
Leslie J
LJ
Samoy
Katie
K
Lacaria
Roy A
RA
Purssell
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D064420:Drug-Related Side Effects and Adverse Reactions; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D004366:Nonprescription Drugs / Q000009:adverse effects; D011446:Prospective Studies; D012720:Severity of Illness Index
D004366:Nonprescription Drugs