Implementing a Syndromic Surveillance System: Objectives, Policy and Cost
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Transcript of Implementing a Syndromic Surveillance System: Objectives, Policy and Cost
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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um
ber
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PRODROME
SEVERE ILLNESS
Rationale
RELEASE
Syndromic Surveillance
Notifiable Disease Reporting
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N
um
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of
Cas
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
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NG
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CK
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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