1.2 Sources Of Health Data Flashcards
who might want to measure disease in populations, and why ?
- researchers (academics, government bodies, non-departmental public bodies, etc)
- Public health campaigners
- Doctors
- Medical students
Ad-hoc samples e.g. local health surveys by CCGs who are CCGs? [there is now a different organisation ?]
Those that give money to hospitals
How do we asses health & disease in populations ?
- Routine surveillance
- Ad-hoc samples
- Examples of routine surveillance
- Although it technically encompassess ….. it can be imperfect
- births, deaths, notifiable diseases
- whole populations
Reliability of evidence from Ad-hoc samples depends largely on …?
sampling strategy
3 examples of routine data
- demographic data (e.g. census, births, deaths, fertility)
- Health events data (e.g. morbidity / mortality)
- Population based health information (e.g. health surveys)
What members of the population might be excluded from routine data surveillance ?
- homeless
- People in war-torn countries
What are advantages of routine data ?
- readily available
- Limited cost
- Useful for establishing baseline characteristics
- Useful for examining trends of disease over time and by place
- Useful for identifying where there is a need
What are disadvantages of routine data ?
- lack of completeness, potential for bias
- Limited details of determinants e.g. ethnicity, income
- Often poorly presented
- Delay between collection and publication
Four examples of demographic data
- Age
- Sex
- Ethnicity
- Religion
An example of a measure in the UK which collects demographic data
Population census
Features of a census
- run by the government
- Covers defined area
- Personal enumeration (or a person in each household completes census form)
- Simultaneous through each area
- Universal coverage
- Occurs at regular intervals (10 yrs in UK)
In the uk, how often is the census taken ?
Census taken every 10 years in the UK
Issues with personal enumeration in census data
- language barriers
- Inability to write or read
What information is recorded in the census ?
- population size = calculate rates
- Population structure = service needs
- Population characteristics = measures of deprivation
Population characteristics, measures of deprivation are what ?
- unemployment
- Overcrowding
- Lone pensioners
- Single parents
- Lack of basic amenities
Define the difference between population estimates and population projections
- Population estimates = apply what is known about births, deaths, migration to the present
- Population projections = apply what is known about births, deaths, migration to the future
Difference between meaning of fecundity & fertility ?
fecundity = ability to produce offspring
fertility = production of live offspring
2 sources of birth data
- Birth notification
- Birth registration
Birth notification
1. completed by …. within ….
2. sent to ….
3. important for ….. e.g. immunisations
- attendant at birth , 36 hours
- local child health register
- relevant services
Birth registration
1. completed by …. within ….
2. submitted to ……
3. important for …..
- parent , 42 days
- local registrar for births
- statistical purposes
Sources of health activity data
- Primary care e.g. GP
- Secondary care e.g. hospital admissions
- Hospital episode statistics
Sources of disease registries and data on chronic conditions
Public health England :
- public health profiles
- Infectious disease surveillance
- National cancer registration and analysis service
3 causes of dramatic changes in epidemiological data trends..
- Chance (random variation)
- Artefactual systematic errors
- Real phenomenon = epidemiological (natural) or the effect of medical care
2 sources of death (mortality) data, completed by who, within how many days, required why ?
- Death certification
- Statutory obligation for attending doctor to complete
- Legally required to include likely cause of death
- If unsure, must contact coroner’s office
- Death registration
- Completed by qualified informant e.g. relative
- Within 5 days to local registrar for deaths
- Requires death certificate from doctor
Why is it important to collect mortality data
- lassify causes of death
- Analyse patterns in mortality rates
- Identify health problems
- Inform service needs
What is a verbal autopsy ?
- family of the decreased is surveyed/ interviewed about the symptoms/ circumstances of the deceased person prior to death
- Info given to doctors to interpret and come up with probable cause of death
What are crude death rates ? & why is age-standardised rates ?
- Measured as deaths per 1,000 per year
- Takes account of population size, but not population structure
- Comparison of crude death rates is usually not very helpful
What are sources of sample-based health information ?
Surveys
Surveys are ___ in which information is __ in variety of methods (e.g. F2F, self-completed questionnaire, telephone, post, online) and the __ of results depend on extent to which survey population is representative
- investigations
- Systematically collected
- Generalisability
Example of sample-based health information (survey in the UK)
- health survey of England
- Collated information on health and related behaviours of 8,000 adults and 2,000 children
- Combined a questionnaire with recording of some physical measurements and blood tests
What is life expectancy at birth ?
predicted average length of life at birth (if current mortality rates continue to apply)
Census data describes what ?
Population size and population structure
Population estimates depend on what factor ?
Migration
Population projections depend on what factors ?
- projected migration
- Fertility rates
What’s the difference between fecundity & fertility ?
Fecundity = ability to produce offspring
Fertility = production of live offspring
