The National Electronic Injury Surveillance System: Cooperative Adverse Drug Events Surveillance System (NEISS-CADES) Aaron B. Mendelsohn, PhD, MPH Office of Drug Safety Food & Drug Administration 18 May 2005

2 History of NEISS-CADES 1971: Consumer Product Safety Commission implemented National Electronic Injury Surveillance System (NEISS) to detect injuries associated with consumer products 2000: NEISS expanded to collect data on all injuries (e.g., violence, occupational, adverse drug events) 2002: NEISS-CADES created through FDA, CDC, and CPSC collaboration to collect specific details (e.g., route of administration) for ADEs

3 NEISS-CADES participating sites Ongoing survey of 64 US health care facilities Stratified probability sample of US hospitals with 24-hour ED and minimum of 6 beds –Selection based upon geographic region, size, and pediatric/adult status –National projections obtainable

4 NEISS Sites

5 NEISS-CADES drug definition Prescription medications Over-the-counter medications Topical medications Vaccinations, immunizations Vitamins, dietary supplements, and herbals

6 Adverse drug event (ADE) definition NEISS-CADES defines an ADE as an injury related to the outpatient use of a drug and resulting from: –Allergic reaction –Side effect –Unintentional overdose –Secondary effect Exclusions: –Intentional drug injuries, e.g., suicide attempts –Injuries resulting from alcohol, tobacco, and illicit drugs

7 Data collected in NEISS-CADES Patient demographics Drug data –Name of medication –Dose, frequency, duration, route –Concomitant medications Patient diagnosis(es) Tests performed and treatments received in ED Patient disposition Brief narrative description of event

8 NEISS-CADES data flow ADE documented in patient chart NEISS coder abstracts data Patient visits ED Analysis Database CPSC removes personal identifiers & quality checks CDC reviews raw data & directs quality control FDA contracts medical coding FDA, CDC collaborate on data analyses Disseminate findings & prevent ADEs

9 Preliminary findings from NEISS- CADES: Pilot study results Conducted by multi-agency / multi-disciplinary team Analysis of data from 9 NEISS-CADES sites –Stratified (hospital size), convenience sample Time period: July 2002 – September 2002 Published in Annals of Emergency Medicine, 2005

10 Characteristics of patients experiencing ADEs (N=598): NEISS-CADES pilot study Patient Characteristicn (%) Age (years) Median (range) 25 th and 75 th percentile 41 (0 – 101) 18, 62 Female sex382 (63.9) Disposition Treated & released Hospitalized Left against med advice Died (in ED) 541 (90.5) 52 (8.7) 5 (0.8) 0 (0)

11 Most common drug classes associated with ADEs: NEISS-CADES pilot study Drug Class ADEs (N=598)% Hospitalized (N=52)% Antimicrobials Diabetic agents Cardiovascular Non-opioid analgesics Psychiatric Opioids Anticoagulants

12 Mechanisms of injury* associated with ADEs: NEISS-CADES pilot study MechanismADEs (N=598)% Hospitalized (N=52)% Unintentional overdose Side effect Allergic reaction Secondary effect *Based upon classifications in BMJ 1998, 316:

13 NEISS-CADES adverse drug event examples 68-year old male with gastrointestinal bleeding following warfarin use, held for observation (unintentional overdose) 54-year old female became hypoglycemic following overdose of insulin, treated and released (unintentional overdose) 7-year old female with rash following antibiotic A, treated and released (allergic reaction) 2-year old male with tremors following albuterol, treated and released (side effect)

14 Current research activities with NEISS-CADES data Analysis of first 12 months of data collection –National estimates –Most important drugs and drug classes –Most common mechanisms of injury –Factors leading to hospitalization Examine ADEs in understudied patient subgroups –e.g., elderly, pediatric patients

15 NEISS-CADES limitations System only captures certain ADEs –Acute events –Outpatient setting –Presented to EDs –Recognized by attending physician Relies on quality and completeness of ED charts Training of coders

16 NEISS-CADES strengths Nationally representative, active surveillance system for detecting ADEs in outpatient setting –Possible to estimate the magnitude of drug safety concern Capable of capturing ADEs related to older drugs and those recently released to market Stability Adaptability

17 NEISS-CADES strengths (continued) Detailed data collection Timeliness –~70% of events within 7 days Successful, cost-efficient collaboration between multiple federal agencies

18 Acknowledgements CPSC –Terri Nelson –Cathleen Irish FDA –Judy Staffa, PhD, RPh –Gerald Dal Pan, MD, MHS –Anne Trontell, MD, MPH CDC –Dan Budnitz, MD, MPH –Kelly Weidenbach, MPH –Lee Annest, PhD Participating NEISS Hospitals –Data Coordinators –Emergency Dept. Staff