Deploying digital health data to optimize influenza surveillance at national and local scales

• Published in: PLoS computational biology 2018-03, Vol.14 (3), p.e1006020-e1006020
• Main Authors: Lee, Elizabeth C, Arab, Ali, Goldlust, Sandra M, Viboud, Cécile, Grenfell, Bryan T, Bansal, Shweta
• Format: Article
• Language: English
• Subjects: Agglomeration; Bayesian analysis; Biology; Computer simulation; Data collection; Data management; Data transmission; Developing countries; Digital data; Digital media; Disease control; Earth Sciences; Environmental factors; Epidemics; Epidemiology; Handbooks; Health care; Health policy; Health risks; Illnesses; Influenza; LDCs; Local population; Mathematical models; Medical personnel; Medical records; Medicine and Health Sciences; Optimization; Pandemics; Partial differential equations; People and Places; Physicians; Prevalence studies (Epidemiology); Public health; Spatial discrimination; Spatial resolution; Statistical inference; Statistics; Surveillance systems
• ISSN: 1553-7358; 1553-734X; 1553-7358
• DOI: 10.1371/journal.pcbi.1006020

The surveillance of influenza activity is critical to early detection of epidemics and pandemics and the design of disease control strategies. Case reporting through a voluntary network of sentinel physicians is a commonly used method of passive surveillance for monitoring rates of influenza-like illness (ILI) worldwide. Despite its ubiquity, little attention has been given to the processes underlying the observation, collection, and spatial aggregation of sentinel surveillance data, and its subsequent effects on epidemiological understanding. We harnessed the high specificity of diagnosis codes in medical claims from a database that represented 2.5 billion visits from upwards of 120,000 United States healthcare providers each year. Among influenza seasons from 2002-2009 and the 2009 pandemic, we simulated limitations of sentinel surveillance systems such as low coverage and coarse spatial resolution, and performed Bayesian inference to probe the robustness of ecological inference and spatial prediction of disease burden. Our models suggest that a number of socio-environmental factors, in addition to local population interactions, state-specific health policies, as well as sampling effort may be responsible for the spatial patterns in U.S. sentinel ILI surveillance. In addition, we find that biases related to spatial aggregation were accentuated among areas with more heterogeneous disease risk, and sentinel systems designed with fixed reporting locations across seasons provided robust inference and prediction. With the growing availability of health-associated big data worldwide, our results suggest mechanisms for optimizing digital data streams to complement traditional surveillance in developed settings and enhance surveillance opportunities in developing countries.