Cornerstones of epidemiology Flashcards
What are descriptive studies?
Describe the distribution of factors in relation to the person, the place and the time
What types of data are descriptive, give examples?
- routine (births and deaths)
- survey (Health survey for England)
- performance management
What are some examples of study designs and what are they used for?
- to assess accuracy of diagnostic tests, cross sectional studies used
- to assess prognosis of disease, cohort study
- to assess pop healthcare needs, ecological studies
- to assess causes and risk factors, use non randomised
- for treatment efficacy, use randomised
What is routine data?
Collected and recorded systematically, without any research questions in mind, simply for administrative reasons
What are some types of routine data?
- health outcome data from hospitals for example
- Exposure and health determinant data e.g air pollution
- Disease prevention data e.g. screening
- Demographic data e.g. cenus
- geographical data e.g. location of GPs
- Health services e.g. bed counts
- Births
- Deaths
What are some advantages of routine data?
- cheap
- already collected
- standardised collection
- comprehensive
- wide range of things recorded
- available for many years
What are some disadvantages of routine data?
- many not answer the question
- not every case may be included
- variation in quality
- validity is variable
- coding may change e.g. ICD9/ICD10
- must be interpreted carefully
What are examples of health outcome data?
- mortality
- cancer
- infectious disease
- pregnancy termination
- congenital abnormalities
- hospital episode statistic
- GP data
- road accidents
What are cross sectional studies used for?
used by healthcare providers for correct allocation of resources and prevention planning
Allows hypothesis development , however cannot establish cause and effect
How is mortality measured and where can data be obtained from?
Death certificates - local registrar of births and death, office of national stats and produced in tables regularly
Where can cancer registrations be obtained and what can they be used for?
- voluntary notification to local registry
- death certificates
- useful for survival info
- useful to determine trends and prevalence
Where are infectious disease notifications obtained?
- doctors
What is QOF?
Quality and outcomes framework - component of GMC for GPs They: - reward - help fund improvements Data is collected in a database
What are administrative hospital admissions data used for?
To classify treatment
What is a finished consultant episode?
time spent under care of a consultant
What is an admission?
stay in hospital, so 1+ episodes and/or hospital transfers
Where can controls be obtained for a case-control study?
must be representative
- neighbourhood
- friends
- family
- hospital
- GP
Advantages of case control study
- good for rare disease
- quick
- cost effective
- investigate many exposures
Disadvantages of case control study
- selection bias
- recall bias
- uncertain of when exposure occurred
- bad for rare exposures
- cannot calculate incidence
What is a case control study?
Comparing odds of being exposed among case and control
What is the procedure for a case control study?
- select control and cases
- obtain info
- compare those exposed in either
What is a cohort study?
A group of people with something in common - they are free of the outcome and over time development is observed (usually prospective)
What is a prospective cohort study?
Compare disease rates in exposed and unexposed. Watch over time
What is a retrospective cohort study?
Done with routine data, look at relationship between exposure and outcome
