Risk factors for adverse drug events among older adults in the ambulatory setting.
OBJECTIVE
To gather information on patient-level factors associated with risk of adverse drug events (ADEs) that may allow focus of prevention efforts on patients at high risk.


METHODS
Nested case-control study.


METHODS
Large multispecialty group practice in New England.


METHODS
All Medicare enrollees cared for by a multispecialty group practice during 1 year (N=30,397 person-years from July 1, 1999, through June 30, 2000). For each patient with an ADE, a control was randomly selected.


METHODS
Data were abstracted from medical records on age, sex, comorbidities, and medication use at the time of the event.


RESULTS
ADEs were identified in 1,299 older adults. Independent risk factors included being female and aged 80 and older. There were dose-response associations with the Charlson Comorbidity Index and number of scheduled medications. Patients taking anticoagulants, antidepressants, antibiotics, cardiovascular drugs, diuretics, hormones, and corticosteroids were at increased risk. In the analysis of preventable ADEs, the dose-response relationship with comorbidity and number of medications remained. Patients taking nonopioid analgesics (predominantly nonsteroidal antiinflammatory drugs and acetaminophen), anticoagulants, diuretics, and anti-seizure medications were at increased risk.


CONCLUSIONS
Prevention efforts to reduce ADEs should be targeted toward older adults with multiple medical conditions or taking multiple medications, nonopioid analgesics, anticoagulants, diuretics, and antiseizure medications.
Meyers Primary Care Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA. tfield@meyersprimary.org
Terry S
TS
Field
Jerry H
JH
Gurwitz
Leslie R
LR
Harrold
Jeffrey
J
Rothschild
Kristin R
KR
DeBellis
Andrew C
AC
Seger
Jill C
JC
Auger
Leslie A
LA
Garber
Cynthia
C
Cadoret
Leslie S
LS
Fish
Lawrence D
LD
Garber
Michael
M
Kelleher
David W
DW
Bates
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects; D000925:Anticoagulants / Q000009:adverse effects; D000927:Anticonvulsants / Q000009:adverse effects; D016022:Case-Control Studies; D004232:Diuretics / Q000009:adverse effects; D004359:Drug Therapy, Combination; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D012737:Sex Factors
D018712:Analgesics, Non-Narcotic; D000925:Anticoagulants; D000927:Anticonvulsants; D004232:Diuretics