# Presentation: 747700

## 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

## 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

## 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

## NEISS Sites

## NEISS-CADES drug definition

- Prescription medications
- Over-the-counter medications
- Topical medications
- Vaccinations, immunizations
- Vitamins, dietary supplements, and herbals

## 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

## 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
*   *

**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

## 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

## Characteristics of patients experiencing ADEs (N=598): NEISS-CADES pilot study

| Patient Characteristic | n (%) |
| --- | --- |
| Age (years)
     Median (range)
     25th and 75th percentile | 
41 (0 – 101)
18, 62 |
| Female sex | 382 (63.9) |
| Disposition
     Treated & released
     Hospitalized
     Left against med advice
     Died (in ED) | 
541 (90.5)
52 (8.7)
5 (0.8)
0 (0) |

## Most common drug classes associated with ADEs: NEISS-CADES pilot study

| Drug Class |        ADEs
       (N=598) |  | 
%  | Hospitalized
(N=52) | 
% |
| --- | --- | --- | --- | --- | --- |
| Antimicrobials |  | 96 | 16.1 | 0 | 0 |
| Diabetic agents |  | 78 | 13.0 | 9 | 17.3 |
| Cardiovascular |  | 51 | 8.5 | 12 | 23.1 |
| Non-opioid analgesics |  | 49 | 8.2 | 1 | 1.9 |
| Psychiatric  |  | 42 | 7.0 | 4 | 7.7 |
| Opioids |  | 39 | 6.5 | 2 | 3.8 |
| Anticoagulants |  | 28 | 4.7 | 8 | 15.4 |

** **

## Mechanisms of injury* associated with ADEs: NEISS-CADES pilot study

| Mechanism | ADEs
(N=598) | 
% | Hospitalized
(N=52) | 
% |
| --- | --- | --- | --- | --- |
| Unintentional overdose | 233 | 43.6 | 38 | 73.1 |
| Side effect | 185 | 30.9 | 8 | 15.4 |
| Allergic reaction  | 155 | 25.9 | 4 | 7.7 |
| Secondary effect | 25 | 4.2 | 2 | 3.8 |

- *Based upon classifications in BMJ 1998, 316:1511-1514.

## 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)

## 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

## 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

## 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

## NEISS-CADES strengths (continued)

- Detailed data collection
- Timeliness
- ~70% of events within 7 days
- Successful, cost-efficient collaboration between multiple federal agencies

## 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