Flashcards in IPS - First Three Sessions Deck (26):
Describe stage one of demographic transition.
Total population low, birth rate and death rate fluctuate at a high level.
Describe stage two of demographic transition.
Birth rate high, death rate decreasing. Total population increasing.
Describe stage 3 of the demographic transition model.
Birth rate decreasing, death rate is low, total population increasing.
Describe stage four of demographic transition.
Birth rate and death rate low, total population high but steady.
What does the theory of economic transition describe?
As per capita income increases, the population transitions from being mostly employed by agriculture to being employed by industry, services and agriculture. Finally, the population is mostly employed by services.
What are two consequences of demographic transition?
An ageing population, and a higher proportion of people with at least one disability.
Give one consequence of economic transition.
Unequal distribution of wealth across the globe.
What is an SDG?
A sustainable development goal
Give three factors that influence population health.
Demographic shape, economic composition, behavioural and lifestyle factors
What is the name given to the distribution of a statistic across an infinite number of samples?
The sampling distribution
True or false - the sample averages are equivalent to the means of the samples?
What is the central limit theorem?
The idea that the distributions of the means of the samples have a similar shape regardless of population distribution/size.
What is a confidence interval?
Usually the 95% confidence interval, which is the range that is likely to contain the mean of the population values 95% of the time.
What two factors influence the size of the 95% confidence interval?
The variation in population values (more variation, wider interval), and the size of the sample (smaller sample, wider interval).
True or false - if a sample is precise then it cannot be biased?
False - a sample can be extremely precise yet still be biased.
What is selection bias (there are three possible ways for it to occur)?
- Study participants are drawn from a sampling frame that is not representative of the general population. This leads to errors in generalisability.
- Groups compared are not from same population. Errors in comparability.
- One of the groups being studied is not representative of the sampling frame. Errors in comparability.
Is generalisability known as internal or external validity?
External. Comparability is internal validity.
What are the two categories of bias?
Selection bias and information bias.
What are the two types of analytical studies?
Cohort studies and case-control studies.
What is risk ratio?
Ratio of "prevalence proportions" of outcome in groups defined by levels of exposure at a particular time. Eg per 1000 person-years.
What is rate ratio?
Ratio of incidence rates of outcome in groups defined by levels of exposure after a particular time period. Eg person 1000 person-years.
What is odds ratio?
Ratio of odds of outcome in groups, defined by levels of exposure at a particular time.
How is prevalence calculated?
Incidence x duration of disease
What is a cohort study?
This involves recruiting individuals and classifying them according to their exposure status. They are then monitored for extended periods.
What is the difference between a prospective and a retrospective cohort study?
Prospective - individuals who have and haven't been exposed are recruited and followed up.
Retrospective - individuals recruited then exposure status calculated from historical documentation.