automated surveillance for adverse drug events at duke university health system peter m. kilbridge,...
TRANSCRIPT
Automated Surveillancefor Adverse Drug Events at Duke
University Health System
Peter M. Kilbridge, M.D.Washington University School of Medicine
AHRQ Technology and Patient SafetySeptember 26, 2007
2
How can we measure adverse events?• Most organizations: Voluntary reporting is the only
mechanism available• Anecdotal
• Misses the majority of events
• Chart review: • Very resource-intensive
• Variable in effectiveness (e.g., implicit vs. explicit review methodologies)
• Not comprehensive
• Computerized surveillance: effective, but rarely employed• Specialized IT requirements
• Still requires significant clinical resources
3
How automated ADE detection works:• Computerized surveillance of patient data
searching for evidence suggesting that an ADE has occurred
• Rules engine uses combinations of data to detect potential ADEs and fire signals
• Signals that fire are investigated by study clinicians to determine causality:whether they represent true ADEs, and if so, grade severity and nature of ADEs.
• Same rules engine for 3 hospitals
4
Examples of Surveillance Rules• Antidote ordered/dispensed• Toxic serum drug level• Physiologic parameters changing +
active order for a medication• Heparin AND rapidly falling platelet
count• Nephrotoxic medication AND rising Cr• Hypoglycemia AND D25, D50 ordered• INR > 4 AND active order for warfarin ...
5
Scoring Causality and Severity
• Causality:
• Probability that a signal represents a true Adverse Drug Event
• Naranjo algorithm (Clin. Pharmaco. Ther. 1981;30:239-245): Score must be probable or defininte to count as an ADE.
• Severity:
• Duke severity scoring system, 0-6 scale
• Like NCC-MERP, 3 and over equals harm to the patient
6
ADE Surveillance: Evaluation Process
Definite or probable?Definite or probable?
Trigger Condition Met
Trigger Condition Met
Independentinvestigation (chart
review, clinician, patient interviews)
Independentinvestigation (chart
review, clinician, patient interviews)
Adverse Event?
Adverse Event?
No
Note to patient chart
Note to patient chart
Grade severityGrade severity Grade causalityGrade causality
Yes
No
Record as AE, causality
unknown
Record as AE, causality
unknown
Follow-up procedures & tracking
• LOS• Outcome• Diagnoses . . .
Follow-up procedures & tracking
• LOS• Outcome• Diagnoses . . .
Inform clinicians that ADE confirmed
Inform clinicians that ADE confirmed
Send to database,
generate reports to P&T, etc.
Send to database,
generate reports to P&T, etc.
Incorporate into patient safety
continuous improvement
cycle
Incorporate into patient safety
continuous improvement
cycle
StartStart
Intervention in care if needed
Intervention in care if needed
Definite or probable?Definite or probable?
Trigger Condition Met
Trigger Condition Met
Independentinvestigation (chart
review, clinician, patient interviews)
Independentinvestigation (chart
review, clinician, patient interviews)
Adverse Event?
Adverse Event?
No
Note to patient chart
Note negative
Possible
Grade severityGrade severity Grade causalityEstablish causality
Yes
No
Record as AE, causality
unknown
Record as AE, causality
unknown
Follow-up procedures & tracking
• LOS• Outcome• Diagnoses . . .
Follow-up procedures & tracking
• LOS• Outcome• Diagnoses . . .
Inform clinicians that ADE confirmed
Inform clinicians that ADE confirmed
Send to database,
generate reports to P&T, etc.
Send to database,
generate reports to P&T, etc.
Incorporate into patient safety
continuous improvement
cycle
Incorporate into patient safety
continuous improvement
cycle
StartStart
Intervention in care if needed
Intervention in care if needed
7
Example: Coagulation-Related ADE
• Alert: warfarin and an INR > 4
• Investigation: Adult patient previously admitted for A. fib, discharged on warfarin. Patient returned to the ED 10 days later feeling unwell; while in the ED, vomited 200cc of bright red blood. INR was 12.3. Patient required FFP and vitamin K, and was transferred to the ICU.
8
Sometimes we find something else:
• Alert: Naloxone
• Investigation: Patient administered Midazolam 2mg IV and Fentanyl 50 mcg for upper GI, plus ? sprays cetacaine for procedure. Later found unresponsive, hypotensive, with respiratory compromise. Naloxone given with no response. Methemoglobin level =13.7. Patient administered methlyene blue 90mg IV with reduction of methemoglobin level to 1.3.
9
DUH ADEs by Category 12 months
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
Ra
te p
er
10
0 A
dm
iss
ion
s
10
ADE rates from computerized surveillance 1991-2005:
Classen et al. 1991 2.5 ADEs per 100 admissions
Jha et al. 1998 4.1 “ “
Duke 2005 – 2 hospitals 4.4, 6.3
Gurwitz 2003 50 ADEs per 1000 pt-yrs (ambulatory)
11
520
7965
ADE Surveillance Voluntary reporting
Total Inpatient ADEs = 585
ADE Surveillance vs. Voluntary Reporting: 4 months
12
DUH ADE Categories by Month
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
2005-02
2005-03
2005-04
2005-05
2005-06
2005-07
2005-08
2005-09
2005-10
2005-11
2005-12
2006-01
Ra
te p
er
10
0 A
dm
iss
ion
s
Anticoagulants
C. difficile colitis
Hyperkalemia
Hypoglycemia
Miscellaneous
Narcotics/Benzodiazepines
Nephrotoxins andIncreased Cr
13
One Hospital’s ADEs by Location12 months
0.00
5.00
10.00
15.00
20.00
25.00
N21
N23
N2T
N31
N32
N33
N3R N41
N42
N43
N51
N52
N53
N56
N57
N5N
N5P N5T
N61
N63
N71
N72
N73
N77
N78
N81
N82
N83
N91
N92
N93
Rat
e p
er 1
000
Pt.
Day
s
14
ADE rates at two hospitals,6 months, 2005
15
Measures to address the problem at problem hospital:
• Clean the rooms of C. diff patients with bleach; switching wipes used on wards to hypochlorite-based product
• Sent letters to MDs, hospital personnel that alcohol foam shouldn't be used for hand hygiene when C. diff a concern; isolation signs updated to include same information
• List of attendings and rooms of patients with C. diff to get a better handle on the problem; feedback as available
• Result:
16
C. difficile colitis, 2 hospitals:
0
0.5
1
1.5
2
2.5
3
3.5
March April May June July August September October
C. d
iffi
cile
co
litis
/100
0 p
atie
nt-
day
s
DRH
DUH
Intervention
17
Pediatrics vs. Adults (12 mo)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
anticoagulants C. diffi cile colitis hyperkalemia hypoglycemia miscellaneous narcotics/Benzos nephrotoxins
Pediatrics
Adults
18
0
2
4
6
8
10
12
14
16
18
20
Analgesic-Narcotic Anticoagulant Antimicrobial Cardiovascular Diuretic Hypoglycemic Immunosuppressant Electrolyte Supplementation Sedative/hypnotic Miscellaneous
VRS
ADE-S
Pediatrics: ADE vs. Voluntary Reporting (12 mo)
19
Automated ADE Surveillance: Challenges
• Looking where the light is: we are limited by available data types• Performs consistently across large populations, but is not
comprehensive• Resource requirement for evaluations• How best to use the data on ADE incidence
• Used as a primary measure of medication safety?
• Is it used to design, implement, monitor safety improvements?
20
Automated ADE Surveillance: Next Steps
• At Washington University / St. Louis Children’s Hospital:• Use Event Detector expert system to detect ADEs in
pediatric inpatients across SLCH
• Surveillance of pediatric patients with chronic disease in the ambulatory setting and across transitions in care (AHRQ R18 Award):
• Cancer, Sickle Cell Disease, Cystic Fibrosis
• Data from clinic notes (text analysis), pharmacy, laboratory, ED, inpatient and ambulatory EMRs
• New trigger types for these particular patient populations
21
Questions?