Infectious Disease Surveillance & National/Health Security

1. Infectious Disease Surveillance & National/Health Security Michael A. Stoto CNSTAT Workshop on Vital Data for National Needs April 30, 2008, Washington DC

2. Outline • “Biosurveillance” for national/health security • Detection of bioterrorist attacks vs. • Situational awareness for public health emergencies • Relationship to the U.S. vital statistics system • Using mortality data to monitor disease outbreaks • Applying vital statistics system ideas for public health surveillance

3. Syndromic surveillance • Biosurveillance / Syndromic surveillance • Near real-time acquisition and use of pre-diagnostic health data for monitoring population health • Builds on existing data systems • Health care, ED chief complaints, medication sales, absenteeism, …NOT vital data • Usually electronic/networked • Statistical analyses used to detect changes •  disease outbreak, especially a covert bioterrorist attack

5. Shewhart Mild Medium Ultra CUSUM Expo

7. Statistical issues • Obtaining and integrating accurate data quickly from a variety of sources • Determining when something is “unusual” • In the presence of highly variable and possibly unstable background variation • When there may be other reasons for changes in the data • Tradeoffs among • Sensitivity • False positive rate (specificity) • Timeliness

8. Practical issues • Patient privacy concerns • HIPAA regulations, state law, etc. • Proprietary concerns and turf issues • Concern about secondary uses of data by others • Operational costs of sharing data • including personnel and IT costs • Information overload • excess flagging at health department end • Ability to interpret and respond at higher levels • Inability to detect small outbreaks • Sense that utility of SS is not yet proven

9. Goals and purpose shifting • From “statistical” approaches • increase in the number of people with common symptoms to detect BT events • cannot detect small numbers of cases, even if very unusual • To “situational awareness” • facilitate physician reporting • active surveillance / case finding • aid in outbreak investigations • real-timemonitoring of disease outbreaks • including, when to cease interventions • information sharing within public health

10. Vital statistics for 21st Century health surveillance? • Given emphasis on timeliness, can vital statistics be used for biosurveillance? • Can Lemuel Shattuck’s 18th Century approach to monitoring health with mortality rates be updated to the 21st Century?

11. Mills et al, Nature. 2004; 432:904-906

13. Downloaded from CDC 4/26/08

14. Vital statistics for health surveillance? • Given emphasis on timeliness, can vital statistics be used for biosurveillance? • Excess P&I mortality • key to what we know now (perhaps then) about the 1918 flu pandemic • major current flu surveillance system • How can modern IT (e.g. E-Vital, EDR) make mortality data more useful for real-time monitoring? • increased timeliness • more geographically representative • improve accuracy of P&I coding • include causes of death other than P&I

15. Vital statistics system approachesfor public health surveillance • Notifiable disease reporting system • state & local function with limited national coordination • mainly what to report • 19th century concept of operations • post card  fax, phone, Internet • CDC Biosense • Notifiable Disease Cooperative Program • state & local ownership of case reports for local action • federal ownership (and standardization and funding) of statistical data for disease surveillance as a national security resource