A visual analytics approach to understanding spatiotemporal hotspots.

As data sources become larger and more complex, the ability to effectively explore and analyze patterns among varying sources becomes a critical bottleneck in analytic reasoning. Incoming data contain multiple variables, high signal-to-noise ratio, and a degree of uncertainty, all of which hinder exploration, hypothesis generation/exploration, and decision making. To facilitate the exploration of such data, advanced tool sets are needed that allow the user to interact with their data in a visual environment that provides direct analytic capability for finding data aberrations or hotspots. In this paper, we present a suite of tools designed to facilitate the exploration of spatiotemporal data sets. Our system allows users to search for hotspots in both space and time, combining linked views and interactive filtering to provide users with contextual information about their data and allow the user to develop and explore their hypotheses. Statistical data models and alert detection algorithms are provided to help draw user attention to critical areas. Demographic filtering can then be further applied as hypotheses generated become fine tuned. This paper demonstrates the use of such tools on multiple geospatiotemporal data sets.

A pandemic influenza modeling and visualization tool.

The National Strategy for Pandemic Influenza outlines a plan for community response to a potential pandemic. In this outline, state and local communities are charged with enhancing their preparedness. In order to help public health officials better understand these charges, we have developed a visual analytics toolkit (PanViz) for analyzing the effect of decision measures implemented during a simulated pandemic influenza scenario. Spread vectors based on the point of origin and distance traveled over time are calculated and the factors of age distribution and population density are taken into effect. Healthcare officials are able to explore the effects of the pandemic on the population through a geographical spatiotemporal view, moving forward and backward through time and inserting decision points at various days to determine the impact. Linked statistical displays are also shown, providing county level summaries of data in terms of the number of sick, hospitalized and dead as a result of the outbreak. Currently, this tool has been deployed in Indiana State Department of Health planning and preparedness exercises, and as an educational tool for demonstrating the impact of social distancing strategies during the recent H1N1 (swine flu) outbreak.

Long-term durability of Crohn's disease treatment with infliximab.

BACKGROUND: There is a paucity of data providing insight into the durability of Crohn's disease treatment with infliximab for periods longer than 12 months. Our aim was to assess the long-term durability of infliximab therapy. MATERIALS AND METHODS: A total of 198 Crohn's patients under a maintenance regimen with infliximab, with at least a 30-month follow-up, were evaluated retrospectively. Long-term response maintenance was estimated using Kaplan-Meier analysis. The effect of specific variables was calculated using logistic regression and proportional hazard regression analyses. RESULTS: Maintenance of response rates at 72 months was estimated to be 66.4% for initial responders and 58.2% for all patients treated. Concurrent immunomodulators enhanced response maintenance in all patients treated, particularly if started >3 months before the initiation of infliximab therapy. Smoking significantly decreased the maintenance of response in initial responders. CONCLUSIONS: Infliximab treatment of Crohn's disease is reasonably durable beyond 12 months. Concurrent immunosuppressive therapy may increase - and smoking may decrease - long-term response maintenance.

Endotracheal intubation for airway protection during endoscopy for severe upper GI hemorrhage.

BACKGROUND: Aspiration of blood may cause significant morbidity during emergent endoscopy for severe upper GI bleeding. Endotracheal intubation is widely performed for airway protection in this setting, but there are few data regarding its efficacy. METHODS: Outcomes were compared for intensive care unit patients with upper GI bleeding for 1 year (1988) during which prophylactic endotracheal intubation was seldom performed before endoscopy, with outcomes during a subsequent year (1992) in which endotracheal intubation was routine for airway protection before or during EGD when there was hematemesis, altered mentation, unstable cardiopulmonary status, or large amounts of blood in the proximal GI tract, or before endoscopic treatment of lesions at high risk for bleeding. RESULTS: Background variables were similar for intensive care unit patients in 1988 (n = 101) and 1992 (n = 119) with respect to number of patients who had shock (respectively, 66.3% vs. 67.2%), cirrhosis (34.7% vs. 38.6%), variceal/portal hypertensive bleeding (22.8% vs. 33.6%), and endoscopic therapy (37.6% vs. 42.0%). Although use of endotracheal intubation specifically for EGD increased significantly between 1988 and 1992 (3.0% vs. 15.1%; p < 0.05), there were no significant changes in endotracheal intubation at any time during hospitalization (24.8% vs. 28.6%), in all EGD-related cardiopulmonary complications (5.0% vs. 3.4%), in new pulmonary infiltrates after EGD (12.9% vs. 15.1%), in mean number of intensive care unit days (7.1 vs. 6.4), or in mortality (15.9% vs. 11.8%). New infiltrates developed in 10 (48%) of 21 patients after EGD despite endotracheal intubation specifically for airway protection. However, in 1992 there were no fatal episodes of aspiration during EGD (2.0% vs. 0%; p = 0.21), no emergent post-EGD endotracheal intubation (6.0% vs. 0%; p < 0.05), and fewer in-hospital cardiopulmonary arrests (12.9% vs. 5.0%; p < 0.05). CONCLUSION: Frequent use of endotracheal intubation for airway protection during EGD for upper GI bleeding requiring intensive care unit admission did not significantly change the relatively high frequency of acquired pneumonia or cardiopulmonary events, but may have prevented the rare fatal episode of massive aspiration. Endotracheal intubation may benefit selected patients with upper GI bleeding, but its specific role remains unclear, and alternative methods of airway protection should be investigated.