Implementing a Syndromic Surveillance System: Objectives,

Policy and Cost

Aaron Fleischauer, PhD, MPH

Bioterrorism Preparedness and Response Program

National Center for Infectious Diseases

Objectives

What is Syndromic Surveillance? Where syndromic surveillance fits in? How it works? Challenges and limitations Policy issues with implementing a system Cost and burden

Definition

“The collection and analysis of health-related data that precede diagnosis and signal a sufficient probability of case or an outbreak to warrant further public health response.”

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PRODROME

SEVERE ILLNESS

Rationale

RELEASE

Syndromic Surveillance

Notifiable Disease Reporting

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es

PRODROME

SEVERE ILLNESS

Rationale

EXPOSURE

Syndromic Surveillance

Notifiable Disease Reporting

Increase sensitivity & timeliness of outbreak

detection

Strategies

1. Make outbreaks of any kind & individual cases of unusual disease officially reportable 24/7

2. Routine use of PFGE fingerprinting (PulseNet) and the Laboratory Response Network (LRN) with sharing of information across states to identify clusters/ cases.

3. Automated analysis of reportable disease/lab data

4. Implement syndromic surveillance

5. Environmental monitoring (e.g., Biowatch, BDS)

Syndromic Surveillance Process

Syndromic Surveillance Data Sources

EMS

Emergency Departments

Nursing Hotlines

Laboratory Tests

Poison Control

School Absentee

Veterinarian Clinics

Over-the-counter

Prescription Drugs

ED collects data on each patient

Step 1

Syndromic Surveillance

Process

ED collects data on each patient

Send data (e.g., 24 hours) via secure server to Health Department

Step 2

Syndromic Surveillance

Process

Electronic ED Data

Date Time Sex Age Birth date Chief Complaint ----------------------------------------------------------08/08/2004 00:28 Female 13 01/31/1991 MIGRAINE NAUSEA08/08/2004 00:38 Female 29 08/23/1974 COUGH,FEVER08/08/2004 00:50 Male 48 09/01/1955 HUMAN BITE TO CHEST08/08/2004 01:44 Male 53 07/29/1951 ABD PAIN, GENERAL 08/08/2004 09:00 Male 6 02/16/1998 N & VOMITING X 308/08/2004 09:21 Male 50 07/21/1954 SPRAIN ANKLE08/08/2004 09:29 Female 1 03/21/2004 CRYING & FUSSINESS08/08/2004 09:42

--

NG

ER

VA

--

CK

s.

x3

- Hospital A, August 8, 2004

Syndromes

[ ] Upper or lower respiratory tract infection with fever

[ ] Diarrhea/ gastroenteritis

[ ] Rash with fever

[ ] Sepsis or non-traumatic shock

[ ] Meningitis or encephalitis

[ ] Botulism-like syndrome

[ ] Unexplained death with history of fever

[ ] Lymphadenitis with fever

[ ] Localized cutaneous lesion

[ ] Myalgia with fever/ rigors and malaise

ED collects data on each patient

Step 3

Syndromic Surveillance

Process

HD performs aberration

detection and analyses

Send data (e.g., 24 hours) via secure server to HD

Hospital can receive reports or view data

Early Aberration Reporting System (EARS)

Washington CountyALL HOSPITALS

Respiratory with Fever/ ILI

Moving 7-day baseline

Signal

ED collects data on each patient

Step 4

Syndromic Surveillance

Process

HD performs aberration

detection and analyses

Signals require further analysis and interpretation

Send data (e.g., 24 hours) via secure server to HD

Hospital can receive reports or view data

Total GI (Last 24 Hrs): 0

Total GI (Last 24 Hrs): 1

Total GI (Last 24 Hrs): 1

Total GI (Last 24 Hrs): 4

Total GI (Last 24 Hrs): 2

Total GI (Last 24 Hrs): 1

Total GI (Last 24 Hrs): 0

Total GI (Last 24 Hrs): 0

Total GI (Last 24 Hrs): 2

Total GI (Last 24 Hrs): 3

ED collects data on each patient

Step 5

Syndromic Surveillance

Process

HD performs aberration

detection and analyses

Signals require further analysis and interpretation

Send data (e.g., 24 hours) via secure server to HD

Hospital can receive reports or view data

Epidemiologists investigate Signals

Phased Response

Phase ISystem attributes

Strengths and limitations of statistical algorithms

Sensitivity and specificity of data types (e.g., over-the-counter pharmaceuticals, chief complaint, diagnoses)

Consideration of data source (e.g., Target population)

Phase IIDescriptive analysis

Performing stratified analyses (by age, gender, time, geography)

Consistency of patient-specific reports

Phase IIIComparisons

Comparisons with alternate data sources

Interpreting of data within context (e.g. OTC drug sales)

Phase IVInvestigation

Field investigation, (Phone call, Visit, Review of records)

Challenges and Limitations

Signal

What questions are being asked of these data? Specific questions to non-specific

data Limitations

Signal to noise (false positives) Signal desensitization Cost and resources

Sufficient Probability

Assessed by performing validations1. Validate syndrome case definitions

2. Validate system to detect outbreaks Sensitivity and specificity

Improving sensitivity Increase false positive rate

Response

What signals warrant further public health response?ThresholdsSufficient size of the eventAmong Syndromes

Do all data sources have a response?Emergency DepartmentsOver-the-counter Pharmaceuticals

Policy Issues

Example: The Boston City Health Commission

Background

Previous outbreak detection systems Reportable Disease Surveillance Volume-based ED surveillance Both mandated by City Regulation

Democratic National Convention Pressure to implement electronic

ED-based syndromic surveillance

Stakeholders

All Hospitals and Urgent Care Centers operating an Emergency Department in Boston

HIPAA Privacy rule expressly permits use of protected

health information for: Reportable disease reporting Public health surveillance Epidemiologic investigation

Includes patient identifiable information Limited Data Set Rule

Public Health Regulation

DISEASE SURVEILLANCE AND REPORTINGREGULATION

PREAMBLE

WHEREAS, The Boston Public Health Commission is charged with protecting, preserving and promoting the health and well-being of all Boston residents, particularly those who are most vulnerable.

WHEREAS, The Boston Public Health Commission is charged with…

Disease Surveillance Regulation

All health care facilities in the City of Boston that operate or maintain anemergency department and/or an urgent care facility, shall report for each visit during a twenty-four (24) hour period, to such emergency department or urgent care facility, the following information about each patient:

a. Age;b. Gender;c. Race/Ethnicity;d. Residential zip code;e. Chief complaint; andf. Diagnostic code (if available).

CSTE concerns

Cost implications of monitoring syndromic surveillance systems and following up aberrations

With BT funding decreasing, evaluation of cost and effectiveness relative to other strategies for early detection of diseases of concern is badly needed

Estimating Cost

Difficult to measure Parameters requiring estimates

Software packages Data transfer mechanisms Person-time and dedicated staff R&D and Maintenance Investigation of aberrations

Estimated Costs: NYC

Start-up costs Developed from post-9/11 drop-in system Paper-based with deployed staff to area hospitals

Electronic system Direct annual costs estimated at $150,000/ year Not including cost associated with:

Research and development Surveillance for non-infectious outcomes Data transmission costs incurred by hospitals

Aberration Detection Software

EARS (Early Aberration Reporting System) Developed by CDC (Lori Hutwagner) Shareware, available free of cost

RODS (Real-time Outbreak Detection Software) Shareware, with ~$350/hour support/consult fees

Other packages from private vendors May average ~$50,000

Final Thoughts

CSTE Recommendation

Need evaluation of syndromic surveillance and a critical determination made as to whether it should be used routinely for aberration detection – or only in special circumstances (public health events)?

We should not be expanding it without evaluation.

CSTE Position on Syndromic/ Bioterrorism

Surveillance

Recommendations:

CDC form an advisory group to review all efforts at improving BT surveillance and advise re: which are worth keeping and funding, which should be encouraged of all states, and which should be scrapped.

www.cste.org - position statements

For more information:

Websites:Websites:

www.syndromic.orgwww.syndromic.org

http://www.cdc.gov/epo/dphsi/syndromichttp://www.cdc.gov/epo/dphsi/syndromic

http://www.bt.cdc.gov/surveillance/earshttp://www.bt.cdc.gov/surveillance/ears

Signal Detection scenario Stoto et al. Chance 2004; 17(1): 19-24

Excess of 9 cases over two days3X daily average50% probability of alarm

Excess of 18 cases over 9 daysNot until 9th day50% probability of alarm