Correlation of National Influenza Surveillance Data to the Local Experience Kate Goodin, MPH Florida Department of Health Bureau of Epidemiology 6 th Annual Public Health Information Network Conference August 26, 2008 Atlanta, GA

Outline Local Influenza Activity Assessment  Influenza Sentinel Surveillance System  County Influenza Activity Code  Pneumonia and Influenza Mortality National Surveillance Data  BioSense Influenza Module, ARI diagnosis at DoD treatment facilities Correlation between National data and local data  State perspective  Areas of BioSense coverage  Areas not represented in BioSense

Purpose To assess whether the health data received into BioSense from Florida is useful in regards to surveillance for influenza and influenza-like illness (ILI) within the State.  Military population  Age  Gender  Location

Influenza Sentinel Provider Surveillance Network 103 providers reporting from around the state  Goal is one provider for every 250,000 people  1:185,958 population Report the number of total visits seen in their office during the previous week, report the number of visits from the previous week that were for influenza-like illness (ILI)  Calculate the rate of ILI per 100 visits Enter this data into a website hosted by the CDC Collect specimens from a sample of ILI patients and forward to the Bureau of Laboratories in Jacksonville or Tampa

County Influenza Activity Assessment Influenza coordinator within each of the 67 County Health Departments Monitor influenza activity within their county  Hospital labs  Assisted living facilities  Syndromic surveillance  Contact providers  Notifiable disease reports (pediatric influenza deaths, outbreaks)  Worker absenteeism  School absenteeism  Correctional institutions Method of surveillance is different in each county Counties report a County Influenza Activity Code to the Bureau of Epidemiology on a weekly basis (similar to state activity code reporting to CDC)

County Influenza Activity Code Enter data as a single number into a website maintained for this purpose 0-No Activity: Overall clinical activity remains low with no laboratory confirmed cases in the county. 1-Sporadic: a. Isolated cases of laboratory confirmed influenza in the county. b. An ILI outbreak in a single setting in the county. (No detection of increased ILI activity by surveillance systems.) 2-Localized: a. An increase in ILI activity detected by a single surveillance system within the county. (An increase in ILI activity has not been detected in multiple surveillance systems.) b. Two or more outbreaks (ILI or laboratory confirmed) detected in a single setting in the county. AND c. Recent (within the past three weeks) laboratory evidence of influenza activity in the county. 3-Widespread: a. An increase in ILI activity detected in >2 surveillance systems in the county. b. two or more outbreaks (ILI or laboratory confirmed) detected in multiple settings in the county.

Week 40 (start) Week 7 (peak) Week 20 (wane) Influenza Season County Influenza Activity Maps

Pneumonia and Influenza Mortality Mortality data is available through the state vital statistics office  Electronic database- Deathmaster Selected ICD-10 codes J10-J18  any mention  and influenza seasons Total number of deaths, deaths due to pneumonia or influenza Calculated the proportion of P&I deaths per 100 deaths

Biosense DoD/VA ARI Data sources for BioSesnse in Florida is limited to:  DoD/VA diagnosis  Lab test order data For Florida, what is available in BioSense is the number of total visits to these outpatient clinics and the number of acute respiratory illness (ARI) diagnosis  Calculate a rate of ARI per 100 visits No non-military hospitals reporting chief complaint or diagnosis data to CDC through BioSense  State legal requirements  State-wide implementation of ESSENCE

70 DoD/VA facilities report in Florida

Question.….. From a national perspective, does the data captured in BioSense give an accurate picture of influenza activity at the local level?  Military population  Age  Gender  Location

State Perspective Analysis C.C.p-valuer-squared P&I mortality (P&I deaths per 100 deaths) % (.00965) ILI rate (ILI diagnosis per 100 visits) < % (.411) County Influenza Activity Code (# counties reporting localized or widespread activity) < % (0.397) Comparing ARI measured at DOD/VA treatment facilities

BioSense Coverage Areas Coverage area: A County with 3 or more reporting facilities

BioSense Coverage Area Analysis C.C.p-valuer-squared P&I mortality (P&I deaths per 100 deaths) % (0.141) ILI rate (ILI diagnosis per 100 visits) < % (0.232) County Influenza Activity Code (# counties reporting localized or widespread activity) < % (0.566) Comparing ARI measured at DOD/VA treatment facilities

Analysis From Areas Not Covered by BioSense C.C.p-valuer-squared P&I mortality (P&I deaths per 100 deaths) < % (0.297) ILI rate (ILI diagnosis per 100 visits) < % (0.299) County Influenza Activity Code (# counties reporting localized or widespread activity) < % (0.335) Comparing ARI measured at DOD/VA treatment facilities

Conclusions The ARI rate measured at DOD/VA treatment facilities was significantly correlated to data measured at the local level for all levels of analysis The level of correlation to the ARI rate measured at DOD/VA treatment facilities was highest for the County Influenza Activity Code in BioSense coverage areas, other correlations were statistically significant but at lower levels BioSense coverage areas:  Broward, Dade, Duval, Escambia, Hillsborough, Pinellas  Large population centers, urban areas  More healthcare coverage Non-coverage areas:  61 counties  Urban population of Orlando, Naples, Sarasota, etc., but mostly rural areas

Contribution of Influenza Surveillance Activities in FL System County level ILI activity State level ILI Prevailing influenza strains Severity of ILI illness Transmissibility of influenza strains Influenza Sentinel Provider Surveillance Network ** County Influenza Activity Code ** P&I Mortality Surveillance System ** DOH Laboratory Surveillance * Notifiable Disease Reports (pediatric influenza mortality) * ILI Outbreak Reports *** BioSense *

Review State  ARI data was significantly correlated to state ILI and County Influenza Activity codes r-squared: 41%, 40%  ARI data not significantly correlated to P&I mortality BioSense coverage areas  County Influenza Activity code was significantly correlated to ARI, correlation coefficient: Areas not covered by BioSense  ARI was significantly correlated to all three measures of county influenza activity but at very low levels 0.544, 0.577, 0.579

Acknowledgements Florida Department of Health  Aaron Kite-Powell  Janet Hamilton  Richard Hopkins BioSense developers

Contact Information: Kate Goodin Florida Department of Health Bureau of Epidemiology Tallahassee, FL