The Impact of a Case of Ebola Virus Disease on Emergency Department Visits in Metropolitan Dallas-Fort Worth, TX, July, 2013 –July, 2015: An Interrupted Time Series Analysis

This study found that ED visits in the Dallas-Fort Worth, Texas metropolitan area increased significantly in both absolute and relative terms immediately after confirmation of the fatal EVD case. Visits for ALL complaints increased by about 12% immediately (~1,123 visits per day) and remained elevated by over 11% (~971 visits per day) at two weeks post-event, returning to baseline on January 22, 2015. The rate of visits for fever with gastrointestinal distress increased by over 40% (~2.5 per 1000 visits per day) immediately and remained elevated by over 35% (~2.3 per 1000 total visits per day) at two weeks post event and returned to baseline on March 20, 2015. Visits for fever with travel to West Africa declined throughout the study period. It is worth noting that while there was an observed increase in ED visits with chief complaints that aligned with EVD-like illness, none of the observed increase in FGI was linked to a confirmed case of EVD and the majority of the observed increase in ED visits occurred outside the EVD-specific symptom profile. Though this study does not prove unequivocally that the fatal EVD case caused a surge in ED visits, a clear pattern of association is observed and it does establish preliminary evidence of causality. Interrupted Time Series analysis is a robust modelling technique; the strongest quasi-experimental method for evaluating the longitudinal effects of an event.10 Our use of segmented regression with autoregressive errors provides a pow...
Source: PLOS Currents Outbreaks - Category: Epidemiology Authors: Source Type: research