Skip to main content

Morbey Roger

Increasingly public health decision-makers are using syndromic surveillance for real-time reassurance and situational awareness in addition to early warning1. Decision-makers using intelligence, including syndromic data, need to understand what the systems are capable of detecting, what they cannot detect and specifically how much reassurance should be inferred when syndromic systems report nothing detected. In this study we quantify the detection capabilities of syndromic surveillance systems used by Public Health England (PHE). The key measures for detection capabilities are specificity and sensitivity (although timeliness is also very important for surveillance systems)2. However, measuring the specificity and sensitivity of syndromic surveillance systems is not straight forward. Firstly, syndromic systems are usually multi-purpose and may be better at identifying certain types of public health threat than others. Secondly, whilst it is easy to quantify statistical aberration detection algorithms, surveillance systems involve other stages, including data collection and human decision-making, which also affect detection capabilities. Here, we have taken a systems thinking approach to understand potential barriers to detection, and summarize what we know about detection capabilities of syndromic surveillance systems in England.

Objective: To communicate the detection capabilities of syndromic surveillance systems to public health decision makers.

Submitted by elamb on

The negative effect of air pollution on human health is well documented illustrating increased risk of respiratory, cardiac and other health conditions. Currently, during air pollution episodes Public Health England (PHE) syndromic surveillance systems provide a near real-time analysis of the health impact of poor air quality. In England, syndromic surveillance has previously been used on an ad hoc basis to monitor health impact; this has usually happened during widespread national air pollution episodes where the air pollution index has reached "High"™ or "Very High"™ levels on the UK Daily Air Quality Index (DAQI). We now aim to undertake a more systematic approach to understanding the utility of syndromic surveillance for monitoring the health impact of air pollution. This would improve our understanding of the sensitivity and specificity of syndromic surveillance systems for contributing to the public health response to acute air pollution incidents; form a baseline for future interventions; assess whether syndromic surveillance systems provide a useful tool for public health alerting; enable us to explore which pollutants drive changes in health-care seeking behaviour; and add to the knowledge base.

Objective:

To explore the utility of syndromic surveillance systems for detecting and monitoring the impact of air pollution incidents on health-care seeking behaviour in England between 2012 and 2017.

Submitted by elamb on

Public Health England's syndromic surveillance service monitor presentations for gastrointestinal illness to detect increases in health care seeking behaviour driven by infectious gastrointestinal disease. We use regression models to create baselines for expected activity and then identify any periods of signficant increases. The introduction of a rotavirus vaccine in England during July 2013 (Bawa, Z. et al. 2015) led to a reduction in incidence of the disease, requiring a readjustment of baselines.

Objective:

To adjust modelled baselines used for syndromic surveillance to account for public health interventions. Specifically to account for a change in the seasonality of diarrhoea and vomiting indicators following the introduction of a rotavirus vaccine in England.

Submitted by elamb on

Syndromic surveillance involves monitoring big health datasets to provide early warning of threats to public health. Public health authorities use statistical detection algorithms to interrogate these datasets for aberrations that are indicative of emerging threats. The algorithm currently in use at Public Health England (PHE) for syndromic surveillance is the ‘rising activity, multi-level mixed effects, indicator emphasis’ (RAMMIE) method (Morbey et al, 2015), which fits a mixed model to counts of syndromes on a daily basis. This research checks whether the RAMMIE method works across a range of public health scenarios and how it compares to alternative methods.

Objective:

To investigate whether alternative statistical approaches can improve daily aberration detection using syndromic surveillance in England.

Submitted by elamb on

Syndromic surveillance is the real-time collection and interpretation of data to allow the early identification of public health threats and their impact, enabling public health action. Statistical methods are used in syndromic surveillance to identify when the activity of indicator ‘signals’ have significantly increased. A wide range of techniques have been applied to syndromic data internationally. As part of the preparation for the 2012 Olympics Public Health England expanded its syndromic surveillance service. As new syndromic systems were introduced, statistical methods were developed and applied for each system, tailored to the particular system challenges at the time, e.g. a lack of historical data, and regular changes to geographical coverage.

Objective

This paper describes the design and application of a new statistical method for real-time syndromic surveillance, used by Public Health England.

Submitted by teresa.hamby@d… on

Within the UK, previous syndromic surveillance studies have used statistical estimation to describe the activity of respiratory pathogens. The Emergency Department Syndromic Surveillance System (EDSSS) was initially developed in preparation of the London 2012 Olympic and Paralympic Games and has continued as a standard surveillance system, with expanding coverage across England and Northern Ireland. All reporting to this system is completely passive, with no extra work required within the ED. The data collection includes the diagnosis for each attendance, where available, using the coding system in use locally. The coding varies by ED with ICD- 10, Snomed-CT and the less detailed NHS Accident and Emergency Diagnosis Tables all in use. The use of diagnosis coding systems with differing levels of detail creates the need to have a variety of syndromic indicators to make best use of the data received.

We aim to describe the trends in respiratory attendances, and their comparison to the known circulating pathogens identified though laboratory surveillance to establish if any single syndromic indicator may be attributed to any one pathogen in particular. We also aim to describe the flexibility in the development of EDSSS syndromic indicators to best fit the data received.

Objective

Can syndromic surveillance using standard emergency department data collected using automated daily extraction be used to describe and alert the onset of the seasonal activity of named respiratory pathogens within the community?

Submitted by teresa.hamby@d… on

We assessed the impact of the London 2012 Olympic and Paralympic Games on syndromic surveillance systems including the incidence of syndromic indictors and total contacts with health care.

Introduction

Mass gatherings can impact on the health of the public including importation of infectious diseases, exposure of international visitors to endemic diseases in the host country and the increased risk of bioterrorist activity. Public health surveillance during mass gatherings therefore affords an opportunity to identify, and quantify any impact (or reassure on the absence of impact) on public health in a timely manner. In preparation for the Games, Public Health England undertook a programme of work to expand the existing suite of syndromic surveillance systems to include daily general practitioner out of hours (GPOOH) consultations and emergency department (ED) attendances at sentinel sites. These new systems complemented existing syndromic surveillance systems offering the opportunity to monitor trends in patient contacts with GPs outside of normal day time opening hours, as well as potentially the more severe end of the disease spectrum which would present at EDs. We assessed the impact of the 2012 Olympics on national surveillance systems, comparing to periods before and after the Games and in previous years and also the impact of specific events during the Games.

Submitted by aising on

Public Health England has developed a suite of syndromic surveillance systems, collecting data from a number of health care sources, and linking to public health action to try and improve the public health benefit of the surveillance.1 We aim to describe this national syndromic service, highlighting the flexibility of the systems in responding to a range of environmental incidents.

Objective

To deliver a national syndromic surveillance service, linking analytical and statistical methods with public health action to provide surveillance support for national public health programmes monitoring the spread of infectious diseases and the health impact of environmental incidents in England.

Submitted by rmathes on

Whilst the sensitivity and specificity of traditional laboratory-based surveillance can be readily estimated, the situation is less clear cut for syndromic surveillance. Syndromic surveillance indicators based upon presenting symptoms, chief complaints or preliminary diagnoses are designed to provide public health systems with support to detect multiple potential threats to public health. There is however, no gold standard list of all the possible ‘events’ that should have been detected. This is especially true in emergency response where systems are designed to detect possible events for which there is no directly comparable historical precedent.

Objective

To devise a methodology for validating the effectiveness of syndromic surveillance systems across a range of public health scenarios, even in the absence of historical example datasets.

Submitted by Magou on

Seasonal rises in respiratory illnesses are a major burden on primary care services. Public Health England (PHE), in collaboration with NHS 111, coordinate a national surveillance system based upon the daily calls received at the NHS 111 telehealth service. Daily calls are categorized according to the clinical ‘pathway’ used by the call handler to assess the presenting complaints of the caller e.g. cold/flu, diarrhoea, rash.

Objective

We compared weekly laboratory reports for a number of seasonal respiratory pathogens with telehealth calls (NHS 111) to assess the burden of seasonal pathogens on this syndromic surveillance system and investigate any potential for providing additional early warning of seasonal outbreaks.

Submitted by rmathes on
Subscribe to Morbey Roger