Using Primary Care Data for ‘Real Time’ Health Protection Surveillance

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Using Primary Care Data for Real Time Health
Protection Surveillance

• Gillian Smith on behalf of primary care
  surveillance team

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UK work
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Birmingham all the Bs
Bullring
Bilbo Baggins
Baltis
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Outline

• Why do we need real time surveillance?
• What primary care systems could we use?
• Two examples of primary care systems used in the
  UK
• NHS DIRECT
• QRESEARCH
• How have these systems been used in heat related
  illness?
• Discussion about way forward

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Why do we need health protection surveillance in
primary care?

• Clinical diagnoses made by GPs (and symptoms
  reported to NHS Direct) offer the ability to
  systematically monitor a variety of
  syndromes/symptoms which could give early warning
  of a health protection issue (microbiological/chem
  ical/radiological)
• To monitor milder illnesses which may not present
  to hospitals
• To monitor illnesses for which laboratory
  specimens not taken ( e.g. influenza,chicken pox)
  
• Assess burden of of infection in primary care
• To assess impact of health protection policies in
  primary care
• To reassure that there has not been an increase
  in symptoms in the community

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Overview of surveillance systems in UK

• Pre primary care based on reported symptoms (
  NHS Direct)
• Spotter schemes based on consultations (e.g.
  RCGP)
• GP databases ( e.g. GPRD and QRESEARCH)

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Why real time surveillance?
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Why real time surveillance?
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Why real time surveillance?
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Why real time surveillance?
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Principles of work

• In collaboration with colleagues working in
  primary care
• Work on syndromes which may be related to
  infection, chemicals or environmental causes
  therefore across the HPA
• Focus on areas where primary care data can
  provide added value to the overall picture

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Background to NHS Direct

• NHS Direct is a telephone health help line.
• Open 24 hours a day, 365 days a year
• Aims to provide the public with health
• advice and information
• First introduced in 1998, providing a
• service in 3 pilot areas
• Now service covers the whole of England and Wales
• 22 sites covering 2.5 million people each

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Aim

• The aim is to identify an increase in symptoms
  that may be caused by the deliberate release of a
  biological or chemical agent, OR MORE COMMON
  INFECTIONS/ HEALTH PROTECTION ISSUES

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How the project works
NHS Direct site 1
NHS Direct site..
NHS Direct site...
NHS Direct site 22
Data collection
NHS Direct National Operations Centre
Health Protection Agency West Midlands Regional
Surveillance Unit
Analyses
Health Protection Agency
Other agencies
Dissemination
NHS Direct sites
Health Protection Units
Department of Health
NHS Direct National Team
PCTs/SHAs
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Data collection

• Call data on 10 key symptoms/syndromes are
  transferred each week day from the 22 call
  centres (covering all of England Wales) to the
  Health Protection Agency at West Midlands
• Cold/flu Cough Fever Difficulty breathing
• Vomiting Diarrhoea
• Double vision Eye problems Lumps Rash
• Heat stroke monitored during summer months
• Call data are broken down by site, symptom,
  age-group and call outcome
• Further details of individual calls including
  postcodes can be requested if needed

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Analysis - control charts

• Control charts constructed for 6 algorithms for
  10 sites (major urban centres).
• Model constructed assuming the Poisson
  distribution using the Gamma distribution to
  account for over-dispersion.
• Incorporate a bank holiday and seasonal factor
  with a day factor and time trend factor included
  if required.
• 99.5 prediction limits are calculated for each
  day. The prediction limit for the "future" is
  based on the average number of total calls
  to-date.
• 99.5 upper prediction limits are also
  constructed for the remaining sites and
  algorithms (where control charts are not
  available) using standard formula (bank
  holiday/day/time trend factors not included).

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(No Transcript)
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Proportion of NHS Direct fever calls (5-15 year
age group) by region
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Benefits of daily call data

• Provided an early indication of a rise in illness
• Surveillance of children not necessarily visiting
  GPs or hospitals
• Response to media - confirmation of regional
  levels
• Daily reporting when needed
• Ongoing monitoring

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NHS Direct callers self-sampling study 2004/05

• Aims of study to answer the following questions
• 1) Can self-sampling by callers to NHS Direct
  give early warning of an increase in influenza
  activity in the community?
• 2) Does self-sampling by callers to NHS Direct
  provide added value over existing surveillance
  systems for influenza?
• 3) What are the implications of introducing
  selfsampling for influenza testing to NHS Direct
  callers and to the NHS Direct service?
•  
•      

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Sampling 2004/2005

• November 2004 February 2005 NHS Direct callers
  (gt15 yrs) in Hampshire, West Midlands and South
  Yorkshire reporting cold/flu were recruited by
  NHS Direct nurses
• Each caller was sent specimen kits containing 2
  nasal swabs, viral transport medium, instructions
  and information, packaging and a pre-paid reply
  envelope
• Callers were asked to return kits to the HPA
  virus lab samples were tested by multiplex PCR
  for Influenza and RSV viruses, and if ()
  cultured for viable virus isolation
• Results were sent back to national influenza
  surveillance team within the HPA CfI and to the
  NHS Direct callers

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Sampling method
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Results

• Response rate 294 kits sent out - 142 samples
  (48) returned
• Positivity rate 23 of 142 samples (16.2) tested
  positive for influenza viruses. Positivity was
  30-40 during peak weeks
• Influenza 23 samples
• Influenza A (H1N1) 3
• Influenza A (H3N2) 16
• Influenza B 4
• RSV 8 samples
• Positive samples included the 2nd community
  sample of influenza A (H1N1), 4th of influenza A
  (H3N2) and 1st influenza B sample received by the
  ERNVL during the 2004/2005 influenza season.
• 7 of 141 callers reported minor problems in
  taking swabs 
• Average time from NHS Direct call to result was 7
  days

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Conclusions from sampling project

• Self-sampling by NHS Direct callers provided
  early warning of influenza circulating in the
  community and detect multiple strains of the
  virus
• The added value of the scheme may lie in
  providing early warning of influenza rather than
  ongoing surveillance throughout the entire season
  
• Despite spending on average a week in transit the
  samples provided good viability for antigenic
  characterization (virus growth by culture) as
  well as for molecular detection
• Proof of concept that the NHS Direct community
  sampling tool can provide high quality and timely
  samples

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HPA/Nottingham University Surveillance Project
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HPA/Nottingham University Surveillance Project
What is QRESEARCH?

• A non-profit making, nationally representative
  sample of volunteering general practices (500)
  who use EMIS general practice computer systems
• Includes data on 8.2 million patients (4 m
  current)
• Some practices have up to 10 years of historical
  data on the database
• Patients and practices within the database are
  completely anonymous no personal/practice
  identifiers are recorded
• QRESEARCH added value lies in the ability to
  link to prescribing data and to undertake
  analyses using socio-economic data (Census,
  Townsend, IMDS, Rurality score etc) uploaded to
  the patient records

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HPA/Nottingham University Surveillance Project
QRESEARCH FILESERVER IN NOTTINGHAM
EMIS FILESERVER
Episodic data transfers
GENERAL PRACTICE TEAM
Download of all coded data and then daily
downloads
Extraction of subsets for researchers morbidity
analyses
Recruitment and informed consent
Activation of QRESEARCH
GP PRACTICE CLINICAL COMPUTER
QRESEARCH TEAM IN NOTTINGHAM
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HPA/Nottingham University Surveillance Project
What is it?

• In April 2004 received funding from HPA for a two
  year pilot project - project now extended to
  March 2008 and funding provided for daily data
  provision ( influenza indicators)
• Aim to investigate the feasibility of providing
  weekly surveillance data and using the QRESEARCH
  database for a number of strategic projects

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HPA/Nottingham University Surveillance Project
routine outputs

• Pilot Weekly Bulletin launched on 11th November
  2004 with three key indicators influenza-like
  illness influenza-like illness with anti-virals
  prescribed vomiting
• Each week the bulletin includes a key messages
  section, highlighting changes to the indicators
• Gradually extended indicators
• Widened distribution of bulletin in July 2005
• Evaluation of usage by HPA and NHS to be
  conducted in 2006/07

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Key indicators monitored weekly (could be
monitored daily)

• Influenza-like illness
• Pneumonia
• Severe asthma
• Wheeze
• Vomiting
• Diarrhoea
• Gastroenteritis
• Mumps
• Measles
• Pertussis
• Heat stroke

• Influenza-like illness with anti-virals
  prescribed
• Uptake of influenza vaccine
• Proportion of those under 5 years with diarrhoea
  prescribed re-hydration therapy
• Impetigo and the proportion treated with fusidic
  acid

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The weekly bulletin

• Weekly bulletins are produced every week
  including over Christmas and New Year
• Includes data for the previous week for a set of
  key indicators which are presented at UK,
  country, region and SHA level

Insert Image
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HPA/Nottingham University Pilot Surveillance
Project routine outputs
UK GP consultation rate (per 100,000) for
Influenza-like illness, 2005/6
Source QRESEARCH weekly outputs
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HPA/Nottingham University Pilot Surveillance
Project routine outputs
UK GP consultation rate (per 100,000) for
Influenza-like illness with anti-virals
prescribed, 2005/6
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HPA/Nottingham University Pilot Surveillance
Project routine outputs
GP consultation rate for influenza-like illness
by Region (rate per 100,000) 2005/6
Source QRESEARCH weekly outputs
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Buncefield incident

• Able to provide information
• on consultations to SHA
• level (and PCT)
• Able to monitor range of conditions (as per
  bulletin)
• Switched on daily reporting and piloted
  extended flu data set
• No unusual increase in respiratory or complaints
  e.g. asthma etc.
• Able to provide data real time to incident
  team

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Pandemic influenza planning

• Data required daily now have capability to do
  this for weekdays (can be switched on in two
  days)
• Can provide data to PCT level
• Extended dataset for influenza related conditions
  and prescribing (QFlu available on 17 million
  patients)
• QFlu has practices from every SHA in England and
  from 292 out of 303 PCTs
• Can provide data on UK ( 30 overall - though
  under- represented in Scotland)
• included in bulletin in last few weeks

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So what has happened as a result of your work?

• EARLY WARNING AND TRACKING OF RISES IN LLNESSS IN
  THE COMMUNITY
• Part of influenza surveillance system and DH
  heat health watch project (exploring utility
  for environmental monitoring)
• Ability to detect sudden rise in
  symptoms/syndromes in the community, both at a
  national, regional level and now local level (
  e.g. norovirus, influenza like illness)
• Able to provide weekly uptake estimates for adult
  vaccinations
• Only national daily surveillance system in UK and
  only national surveillance system using a health
  help-line in the world
• PROVIDING REASSURANCE DURING TIMES OF PERCIVED
  HIGH RISK
• e.g. Ricin incident , London bombings and
  Buncefield data used by incident teams and
  quoted publicly by HPA
• MONITORING OF HEALTH PROTECTION POLICIES
• e.g. use of antibiotics post SMAC report -
  increase in three day courses (compared to longer
  course) of trimethoprim for UTIs)

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Summary So what has happened as a result of
your work? (contd.)

• EXERCISES
• Daily data used regularly in Exercises ( e.g.
  heat wave, bioterrorist and influenza) and
  provided only consistent daily data feed for
  Exercise United Endeavour
• PANDEMIC INFLUENZA PLANNING
• Helped in stopping proliferation of local
  spotter practice schemes ( as part of influenza
  pandemic planning) to monitor FLI - will be
  provided in consistent and standard way
• Able to provide information on where anti-virals
  being used for FLI
• NHS Direct can provide an alternative source of
  specimens if needed (from patients directly)
• Provided daily data for modellers
• PEER REVIEWED PUBLICATIONS

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August 2003 Heat-wave
Temperature distribution across Europe on 10
August 2003 at 1500hrs British Summer Time
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Heat-health watch

• Heatwave plan for England and Wales - Summer 2004
• By the time a heatwave starts the window of
  opportunity for effective action is very short
  indeed
• The HPA, in collaboration with NHS Direct, will
  refine mechanisms for the surveillance of
  increased heat-related illness with the aim of
  being able to provide daily real-time reports to
  the Department of Health.
• These will provide a source of intelligence on
  (a) how severe the effects are, and (b) how well
  services are responding.
• DH - Heatwave Plan - 2004 dataNHS Direct Met
  Office

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Published by Department of Health26 July 2004
http//www.dh.gov.uk/PublicationsAndStatistics/Pub
lications/
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HPA responsibilities
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Heat Watch Plan NHS Direct surveillance
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Surveillance summer 2005
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Surveillance summer 2005
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Surveillance summer 2005
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So what about heat related work?
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Is there utility and if so how might we improve
this?

• Can primary care data provide any added value
  in either early detection of health problems or
  assessing size of health problems?
• What morbidity indicators would be useful? now
  ability to look at more unusual endpoints
  (neurological)
• Can we be clever in our prescribing linked to
  morbidity indicators?
• ?? Select risk groups for ongoing surveillance
  (able to do so with new GP system)
• When should we switch on daily reporting?

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The English Summer!?