Frequency Flashcards
What is meant by prevalence?
Proportion of the given population at risk that are “cases” at a specific time
What is meant by incidence?
Measure of new “case” occurrence in a “case-free” population at risk during a specific time period
What are the two different types of standardised rates?
Direct
Indirect
What is meant by ecological study?
Comparing aggregate rates across populations
What is meant by cross-sectional study?
A survey that gives rich info in large group of people- at one point in time
What happens in a case-control study?
Groups of cases are compared with group of people without the condition and compare the distribution of given risk factors across the two groups
What are the positives about a case control study?
Cheap and effective
What are the negatives about a case control study?
Retrospective design
What happens in a cohort design?
Examine a large group of individuals when healthy and then follow them up
What are the advantages of cohort design study?
Time sequence of events known
What are the disadvantages of cohort design study?
Long duration
What is meant by internal validity?
When the comparison is free from bias
