Emergency Department Syndromic Surveillance System Research Articles

How Should We Be Conducting Routine Analysis of Traditional Emergency Department Syndromic Surveillance Data?

This roundtable will focus on how traditional emergency department syndromic surveillance systems should be used to conduct daily or periodic disease surveillance. As outbreak detection using these systems has demonstrated an equivocal track record, epidemiologists have sought out other interesting uses for these systems. Over the numerous years of the International Society for Disease Surveillance (ISDS) Conference, many of these studies have been presented; however, there has been a dearth of discussion related to how these systems should be used. This roundtable offers a forum to discuss best practices for the routine use of emergency department syndromic surveillance data.

Using an Emergency Department Syndromic Surveillance System to investigate the impact of extreme cold weather events

This report describes the development of novel syndromic cold weather public health surveillance indicators for use in monitoring the impact of extreme cold weather on attendances at EDs, using data from the 2010–11 and 2011–12 winters.A number of new surveillance indicators were created specifically for the identification and monitoring of cold weather related ED attendances, using the diagnosis codes provided for each attendance in the Emergency Department Syndromic Surveillance System (EDSSS), the first national syndromic surveillance system of its kind in the UK. Using daily weather data for the local area, a time series analysis to test the sensitivity of each indicator to cold weather was undertaken.Diagnosis codes relating to a health outcome with a potential direct link to cold weather were identified and assigned to a number of ‘cold weather surveillance indicators’. The time series analyses indicated strong correlations between low temperatures and cold indicators in nearly every case. The strongest fit with temperature was cold related fractures in females, and that of snowfall was cold related fractures in both sexes.Though currently limited to a small number of sentinel EDs, the EDSSS has the ability to give near real-time detail on the magnitude of the impact of weather events. EDSSS cold weather surveillance fits well with the aims of the Cold Weather Plan for England, providing information on those particularly vulnerable to cold related health outcomes severe enough to require emergency care. This timely information aids those responding to and managing the effects on human health, both within the EDs themselves and in the community as a whole.

The impact of thunderstorm asthma on emergency department attendances across London during July 2013

BackgroundThis study illustrates the potential of using emergency department attendance data, routinely accessed as part of a national syndromic surveillance system, to monitor the impact of thunderstorm asthma.MethodsThe Emergency Department...

Influenza assessment centres: a case study of pandemic preparedness to alleviate excess emergency department volume

Influenza assessment centres (IACs) were deployed to reduce emergency department (ED) volumes during the pH1N1 influenza outbreak in the Kingston, Frontenac, Lennox and Addington (KFL&A) public health region of Ontario, Canada, in the fall of 2009. We present a case study for the deployment of IACs to reduce ED visit volume during both periods of pandemic and seasonal communicable disease outbreak. An emergency department syndromic surveillance system was used to trigger the deployment of eight geographically distributed IACs and to time their staggered closure 3 weeks later. We compared actual and expected ED visit volumes in the KFL&A region to neighbouring regions where no IACs operated by time series regression analysis before, during, and after IAC operation. The deployment of IACs was triggered with a rise in overall ED volume at the hospitals in the KFL&A region to a level 10% above the 6-month running average. The IACs assessed 2,284 patients during 3 weeks of operation. Thirty-three patients were admitted directly to the hospital from the IACs, bypassing the EDs. During the operation of the IACs, the hospitals in the KFL&A region experienced a modest decrease in daily visits when compared to the 3 previous weeks. Overall ED visit volume in the hospitals in the neighbouring regions increased 105% during the period of IAC operation. Operating stand-alone influenza IACs may reduce ED volumes during periods of increased demand, as observed during an anticipated pandemic situation.

When it Rains it Pours: Real-time Situational Awareness for Two Weather Emergencies in Connecticut

During 2011 Connecticut was impacted by two major weather events. The Hospital Emergency Department Syndromic Surveillance System (HEDSS) was utilized to provide real-time situational awareness during the response and recovery phases of both storm events. Increased emergency department utilization for carbon monoxide exposure, asthma, and hypothermia were observed. HEDSS data were likely an underestimation of true disease/injury in the community following the storm events. HEDSS should continue to be used, in conjunction with other existing surveillance systems, for near real-time situational monitoring during public health emergencies.

Analysis of Heat Illness using Michigan Emergency Department Syndromic Surveillance

During a severe heat wave in Michigan in 2012, heat-related Emergency Department cases were identified using the Michigan Emergency Department (ED) Syndromic Surveillance System. Heat-related ED visits were analyzed by patient age, gender, and chief complaint. These ad hoc enhanced analyses were performed by Michigan Department of Community Health epidemiologists and provided to public health partners for situational awareness and to guide their responses to the heat event. Significant differences in the patterns of heat-related illnesses were observed during the heat-wave period compared to a reference period.

Emergency Department Surveillance as a Proxy For The Prediction of Circulating Respiratory Viral Disease in Eastern Ontario

Seasonal outbreaks of winter respiratory viruses are responsible for increases in morbidity and mortality in the community. Previous studies have used hospitalizations, intensive care unit and emergency department (ED) visits as indicators of seasonal influenza incidence. To evaluate whether ED visits can be used as a proxy to detect respiratory viral disease outbreaks, as measured by laboratory confirmation. An Emergency Department Syndromic Surveillance system was used to collect ED chief complaints in Eastern Ontario from 2006 to 2010. Comparable laboratory-confirmed cases of respiratory viral infections were collected from the Public Health Ontario Laboratory in Kingston, Ontario. Correlations between ED visits and laboratory-confirmed cases were calculated. Laboratory-confirmed cases of selected respiratory viruses were significantly correlated with ED visits for respiratory and fever/influenza-like illness. In particular, respiratory syncytial virus (Spearman's rho = 0.593), rhinovirus (Spearman's rho = 0.280), influenza A (Spearman's rho = 0.528), influenza B (Spearman's rho = 0.426) and pH1N1 (Spearman's rho = 0.470) increased laboratory test levels were correlated with increased volume of ED visits across a number of age demographics. For the entire study population and all studied viruses, the Spearman's rho was 0.702, suggesting a strong correlation with ED visits. Laboratory-confirmed cases lagged in reporting by between one and two weeks for influenza A and pH1N1 compared with ED visit volume. These findings support the use of an Emergency Department Syndromic Surveillance system to track the incidence of respiratory viral disease in the community. These methods are efficient and can be performed using automated electronic data entry versus the inherent delays in the primary care sentinel surveillance system, and can aid the timely implementation of preventive and preparatory health interventions.

Developing a new syndromic surveillance system for the London 2012 Olympic and Paralympic Games.

Syndromic surveillance is vital for monitoring public health during mass gatherings. The London 2012 Olympic and Paralympic Games represents a major challenge to health protection services and community surveillance. In response to this challenge the Health Protection Agency has developed a new syndromic surveillance system that monitors daily general practitioner out-of-hours and unscheduled care attendances. This new national system will fill a gap identified in the existing general practice-based syndromic surveillance systems by providing surveillance capability of general practice activity during evenings/nights, over weekends and public holidays. The system will complement and supplement the existing tele-health phone line, general practitioner and emergency department syndromic surveillance systems. This new national system will contribute to improving public health reassurance, especially to meet the challenges of the London 2012 Olympic and Paralympic Games.

Establishing an emergency department syndromic surveillance system to support the London 2012 Olympic and Paralympic Games

BackgroundThe London 2012 Olympic and Paralympic Games is a mass gathering event that will present a major public health challenge. The Health Protection Agency, in collaboration with the College of...

Evaluating the New York City Emergency Department Syndromic Surveillance for Monitoring Influenza Activity during the 2009-10 Influenza Season

Objective: To use laboratory data to assess the specificity of syndromes used by the New York City emergency department (ED) syndromic surveillance system to monitor influenza activity. Design: For the period from October 1, 2009 through March 31, 2010, we examined the correlation between citywide ED syndrome assignment and laboratory-confirmed influenza and respiratory syncytial virus (RSV). In addition, ED syndromic data from five select NYC hospitals were matched at the patient and visit level to corresponding laboratory reports of influenza and RSV. The matched dataset was used to evaluate syndrome assignment by disease and to calculate the sensitivity and specificity of the influenza-like illness (ILI) syndrome. Results: Citywide ED visits for ILI correlated well with influenza laboratory diagnoses (R=0.92). From October 1, 2009, through March 31, 2010, there were 264,532 ED visits at the five select hospitals, from which the NYC Department of Health and Mental Hygiene (DOHMH) received confirmatory laboratory reports of 655 unique cases of influenza and 1348 cases of RSV. The ED visit of most (56%) influenza cases had been categorized in the fever/flu syndrome; only 15% were labeled ILI. Compared to other influenza-related syndromes, ILI had the lowest sensitivity (15%) but the highest specificity (90%) for laboratory-confirmed influenza. Sensitivity and specificity varied by age group and influenza activity level. Conclusions: The ILI syndrome in the NYC ED syndromic surveillance system served as a specific but not sensitive indicator for influenza during the 2009-2010 influenza season. Despite its limited sensitivity, the ILI syndrome can be more informative for tracking influenza trends than the fever/flu or respiratory syndromes because it is less likely to capture cases of other respiratory viruses. However, ED ILI among specific age groups should be interpreted alongside laboratory surveillance data. ILI remains a valuable tool for monitoring influenza activity and trends as it facilitates comparisons nationally and across jurisdictions and is easily communicated to the public.

Evaluation of the Connecticut hospital emergency department syndromic surveillance system for monitoring of community gastrointestinal illness

Evaluation of the Connecticut hospital emergency department syndromic surveillance system for monitoring of community gastrointestinal illness

Syndromic Surveillance during Pandemic (H1N1) 2009 Outbreak, New York, New York

We compared emergency department and ambulatory care syndromic surveillance systems during the pandemic (H1N1) 2009 outbreak in New York City. Emergency departments likely experienced increases in influenza-like-illness significantly earlier than ambulatory care facilities because more patients sought care at emergency departments, differences in case definitions existed, or a combination thereof.

Analysis of the Korean Emergency Department Syndromic Surveillance System: Mass Type Acute Diarrheal Syndrome

ObjectivesThis study was designed to compare the data from the emergency department syndromic surveillance system of Korea in detection and reporting of acute diarrheal syndrome (mass type) with the data from the Korea Food and Drug Administration. And to offer fundamental materials for making improvements in current surveillance system was our purpose.MethodsA study was conducted by reviewing the number of cases reported as acute diarrheal syndrome (mass type) from the Korean Center for Disease Control and Prevention between June, 2002 and July, 2008. And the data were compared with the number of mass food poisoning cases during the same period, reported from the Korea Food and Drug Administration. The difference between two groups was measured and their transitions were compared.ResultsThe emergency department syndromic surveillance system's reports of the numbers of acute diarrheal syndrome (mass type) cases were different from the transition of mass food poisonings, reported by the Korea Food and Drug Administration. Their reports were not accurate and they could not follow the trends of increase in mass food poisonings since 2002.ConclusionsCurrent problems in the emergency department syndromic surveillance system in Korea are mostly related to inaccuracies of daily data reporting system. Manual data input by the reporters could play a big role in such inaccuracies. There need to be improvements in the ways of reporting data, such as automated information transport system linking electronic medical record.

Emergency department syndromic surveillance system for early detection of 5 syndromes: a pilot project in a reference teaching hospital in Genoa, Italy.

Early detection is fundamental for achieving effective control of infectious disease outbreaks. We described the development of a local chief complaint emergency department (ED)-based syndromic surveillance system to improve public health response in Genoa, Italy. The five syndromes under investigation by the syndromic surveillance system were influenza-like illness (ILI), low-respiratory tract illness (LRTI), not-haemorrhagic gastroenteritis, acute hepatitis, fever-with-rash (maculo-papular or vescicular) syndrome. Syndrome coding, data capture, transmission and processing, statistical analysis to assess indicators of disease activity and alert thresholds, and signal response were operatively described. Preliminary results on ILI syndromic surveillance showed that new system allowed the activation of the alert state with a specificity of 90.3% and a sensitivity of 72.9% in predicting epidemiological relevant events, such as > or = 10 accesses to ED for ILI in 3 days. The new syndromic surveillance system allowed to alert the public health institutions 2.5 days before than the local surveillance system based on sentinel physicians and paediatricians, permitting the early activation of the necessary measures for the containment and for burden reduction of the epidemic event. It is noteworthy that the syndromic surveillance epidemic cut-off was overcome once before and 4 times after influenza outbreak detected by sentinel-based surveillance system: all episodes were contemporary with Respiratory Syncytial Virus and Parainfluenza Virus circulation, as detected by regional reference laboratory.

Identifying pneumonia outbreaks of public health importance: can emergency department data assist in earlier identification?

To retrospectively review the performance of a near real-time Emergency Department (ED) Syndromic Surveillance System operating in New South Wales for identifying pneumonia outbreaks of public health importance. Retrospective data was obtained from the NSW Emergency Department data collection for a rural hospital that has experienced a cluster of pneumonia diagnoses among teenage males in August 2006. ED standard reports were examined for signals in the overall count for each respiratory syndrome, and for elevated counts in individual subgroups including; age, sex and admission to hospital status. Using the current thresholds, the ED syndromic surveillance system would have trigged a signal for pneumonia syndrome in children aged 5-16 years four days earlier than the notification by a paediatrician and this signal was maintained for 14 days. If the ED syndromic surveillance system had been operating it could have identified the outbreak earlier than the paediatrician's notification. This may have permitted an earlier public health response. By understanding the behaviour of syndromes during outbreaks of public health importance, response protocols could be developed to facilitate earlier implementation of control measures.

The National Capitol Region's Emergency Department syndromic surveillance system: do chief complaint and discharge diagnosis yield different results?

We compared syndromic categorization of chief complaint and discharge diagnosis for 3,919 emergency department visits to two hospitals in the U.S. National Capitol Region. Agreement between chief complaint and discharge diagnosis was good overall (kappa=0.639), but neurologic and sepsis syndromes had markedly lower agreement than other syndromes (kappa statistics 0.085 and 0.105, respectively).

New Hampshire emergency department syndromic surveillance system

New Hampshire emergency department syndromic surveillance system

Enhanced drop-in syndromic surveillance in New York City following September 11, 2001.

After the 2001 World Trade Center disaster, the New York City Department of Health was under heightened alert for bioterrorist attacks in the city. An emergency department (ED) syndromic surveillance system was implemented with the assistance of the Centers for Disease Control and Prevention to ensure early recognition of an increase or clustering of disease syndromes that might represent a disease outbreak, whether natural or intentional. The surveillance system was based on data collected 7 days a week at area EDs. Data collected were translated into syndromes, entered into an electronic database, and analyzed for aberrations in space and time within 24 hours. From September 14-27, personnel were stationed at 15 EDs on a 24-hour basis (first staffing period); from September 29-October 12, due to resource limitations, personnel were stationed at 12 EDs on an 18-hour basis (second staffing period). A standardized form was used to obtain demographic information and classify each patient visit into 12 syndrome categories. Seven of these represented early manifestations of bioterrorist agents. Data transfer and analysis for time and space clustering (alarms) by syndrome and age occurred daily. Retrospective analyses examined syndrome trends, differences in reporting between staffing periods, and the staff's experience during the project. A total of 67,536 reports were received. The system captured 83.9% of patient visits during the first staffing period, and 60.8% during the second staffing period (P < 0.01). Five syndromes each accounted for more than 1% of visits: trauma, asthma, gastrointestinal illness, upper/lower respiratory infection with fever, and anxiety. Citywide temporal alarms occurred eight times for three of the major bioterrorism-related syndromes. Spatial clustering alarms occurred 16 times by hospital location and 9 times by ZIP code for the same three syndromes. No outbreaks were detected. On-site staffing to facilitate data collection and entry, supported by daily analysis of ED visits, is a feasible short-term approach to syndromic surveillance during high-profile events. The resources required to operate such a system, however, cannot be sustained for the long term. This system was changed to an electronic-based ED syndromic system using triage log data that remains in operation.