Lecture #28 - Surveillance Flashcards
Epidemiological surveillance is what?
What is the definition?
It’s the ongoing descriptive epi (understanding the ongoing story and how to influence it)
It’s an organised ongoing collection, analysis and interpretation of relevant health data - disease and/or risk - in a population, to plan action to reduce risk of morbidity and mortality
What is the basic flow chart of surveillance?
You have DATA COLLECTION (need to know what to collect), then you have ANALYSIS of the data (so can do comparisons) and then you INTERPRET that data and then there is DISSEMINATION of that data to those people who have to know/can change stuff and then there is ACTION.
Data collection:
Surveillance need to be ______
-two bullet points about this
Surveillance need to be ORGANISED
- What diseases/risk (know what to look at)
- practical, clear case definition (often asking other people to report so they should know whether to report this disease or not) - Workable, uniform and continuous data collection system
- can be active or passive
(Data collection) Types of surveillance:
- Passive surveillance - what is this based on?
- Active surveillance - having a system…..
- Sentinel surveillance - surveillance established to……
- Passive: based on reports by health care worker (even if ‘notifiable’ disease, it might not happen)
- maybe they’ve been asked to report on particular disease - some diseases are notifiable means they’re legally required to be reported but that doesn’t mean they’re always reported (up to individual to somehow report and they often don’t - Active: having a system established to report all cases
- routine lab reporting of all diagnosed infections
- better in reporting all cases e.g. the labs are organised - not dependent on individual so if disease diagnosed in that lab then that notification gets sent to the centre - Sentinel: surveillance established to signal trends and may not cover whole population
- sentinel GP practices monitor flu in nZ each year
- so they’re set up to report when GP diagnose influenze - they indicate level and rate of flu in NZ
- only ‘some’ practises and those can be the ones in the higher risk regions
(Data collection) What diseases?
- Rough examples
- Rough examples of the first one
- Infectious diseases (bc ability to change) e.g. MCD, polio, zika etc
- Non-communicable disease (e.g. type 2 diabetes because if this changes then something is up)
- Congenital abnormalities etc
Bascially, need to be clear about what report
(Data collection) Meningococcal disease (MCD)
-go read it and don’t press 5 until you have
-
Analysis:
- _____ of cases (once confirmed disease)
- If possible examine……(4)
- MCD - go have a read
- Number
- ….change descriptive epi in more detail:
- “person” = age, sec, ethnicity, SES (demographic characteristics - see if any particular demographic group who’s at more/less risk)
- “place” = within NZ, comparison with other countries
- “time” = as surveillance continues change overtime very important (have we introduced an intervention that’s decreasing numbers or is it getting worse etc so let’s do more about it)
- Where possible, use rates (cases/time?)
Interpretation:
- “_____ _____ _____”
- Put all the info you read from the analysis stage into one sentence that’s interpreting the data
- What’s going on
- In early 1990s, ongoing worsening outbreak (epidemic) of particular subtype of MCD particularly affecting young Pacific and Maori children in South Auckland, Northland and Bay of Plenty
Dissemination to plan action
1. Disseminate to who? Give four examples
- To those “who needs know”
- Ministry of health (they will coordinate response and organise study of risks)
- District health boards (responsible for organising health care in their areas)
- GPs/Plunket nurses (health professions in that area need to know because it may look like fu in early stages so need to know so carefully diagnose
- The effected population
Action - with MCD, how to do it?
Encourage early assessment of sick children and early treatment of those with suspect MCD
Could be public (door-to-door encourage fams to seek help)
Could be health professional e.g. awareness encourage pre-hospital antibiotics etc
Since there was little known about the risks, what was undertaken?
What did they find so what was their proposed actions?
Analytical epic study (case control)
Found overcrowding was the biggest risk factor so we can try reduce that but usually people don’t live in big crowded houses for the lols - it’s about financial status
Can reduce sharing of pacifiers etc but only small change with this
There was a big action with the vaccine strategy
Go read the rest
Read the Polio and Zika
-
Summary:
- Surveillance identified what?
- Descriptive epi identified what?
- Local action aims to…..
- Analytical epi identified what?
- Action taken required what?
- ….an evolving problem
- …..those most at risk
- ……increase care seeking behaviour and urgent treatment (monitoring showed those who were treated with antibiotics had better outcome - was delayed)
- ……risks
- …….the development of a vaccine that was implemented (difficult to determine the actual impact of vaccine)
Describe the different types of surveillance systems.
Passive surveillance relies on the health provider remembering to send through health information to the relevant health authority (including when there is a requirement by law to do so). This type of surveillance may be inexpensive and not require many resources, however one drawback is that it might not result in a complete reporting of all events. For example, the New Zealand Centre for Adverse Reactions Monitoring is a passive, voluntary surveillance system where health providers, patients, and drug manufacturers may file patient reports of suspected side effects of drugs, however because it is a voluntary system it is likely that there is substantial under-reporting of events.
Active surveillance is when an authority actively contacts the health provider for relevant information. This type of surveillance is more resource intensive and expensive than passive surveillance, but may provide more complete health data resulting in a more accurate and immediate description of what is happening in a population. For example, during an outbreak of measles, healthcare providers may be contacted directly for the details of any suspected measles cases.
Sentinel surveillance is a system that is setup to report on specific risk factors or outcomes that may indicate that a particular preventive or therapeutic activity is not working as planned. For example, a sample of GP clinics may be recruited to report on the number and severity of influenza patients during the flu season. This type of surveillance may provide evidence of trends in diseases or risk factors, or provide an early warning system that a risk factor or outcome is increasing in a population. Sentinel surveillance can be passive or active.
What is surveillance information used for?
Surveillance information is used to identify and monitor trends in population health, including identifying outbreaks/epidemics and emerging health problems. Surveillance data can also be used to generate hypotheses for analytic investigations, as well as monitoring and evaluating intervention programmes. This can all help with planning for on-going and future health services.
