An integrated framework for the geographic surveillance of chronic disease.
BACKGROUND
Geographic public health surveillance is concerned with describing and disseminating geographic information about disease and other measures of health to policy makers and the public. While methodological developments in the geographical analysis of disease are numerous, few have been integrated into a framework that also considers the effects of case ascertainment bias on the effectiveness of chronic disease surveillance.


RESULTS
We present a framework for the geographic surveillance of chronic disease that integrates methodological developments in the spatial statistical analysis and case ascertainment. The framework uses an hierarchical approach to organize and model health information derived from an administrative health data system, and importantly, supports the detection and analysis of case ascertainment bias in geographic data. We test the framework on asthmatic data from Alberta, Canada. We observe high prevalence in south-western Alberta, particularly among Aboriginal females. We also observe that persons likely mistaken for asthmatics tend to be distributed in a pattern similar to asthmatics, suggesting that there may be an underlying social vulnerability to a variety of respiratory illnesses, or the presence of a diagnostic practice style effect. Finally, we note that clustering of asthmatics tends to occur at small geographic scales, while clustering of persons mistaken for asthmatics tends to occur at larger geographic scales.


CONCLUSIONS
Routine and ongoing geographic surveillance of chronic diseases is critical to developing an understanding of underlying epidemiology, and is critical to informing policy makers and the public about the health of the population.
Yiannakoulias
Nikolaos
N
School of Geography and Earth Sciences, 1280 Main Street West, McMaster University, Hamilton, Ontario L8S4K1, Canada. yiannan@mcmaster.ca
Svenson
Lawrence W
LW
Schopflocher
Donald P
DP
D000293:Adolescent; D000328:Adult; D000416:Alberta / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease / Q000453:epidemiology*; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D044382:Population Groups; D011159:Population Surveillance / Q000379:methods*; D011634:Public Health; D011640:Public Policy; D055815:Young Adult