Y2 Session 2 - Epidemiology and Research Skills Flashcards
What does qualitative research do?
It explores underlying ideas and themes to inform research questions and expresses findings in words.
Generally detailed but has a smaller number of participants.
What are odds?
Odds are ratios, so number of people with a disease/number of people who don’t
Usually number from 0-1
How do we calculate prevalence?
Number of people with the disease/total number of individuals in the population
We have to specify the time when we discuss prevalence.
It can be in numbers of percentages.
What is the definition of prevalence?
The proportion of individuals in a population who have the attribute at a specific timepoint
What is cumulative incidence?
The proportion of the population with a new event (e.g. disease) during a given time period.
How do we calculate cumulative incidence?
Number of new cases during a period of interest/number of disease free individuals at the start of this time period.
Always state the time period.
What is person-time?
The amount of time a participants takes in a study
How do we measure incidence rate?
Number of new cases during the follow up period/total person-time by disease-free individuals
ALWAYs express units of person-time e.g. person-hours
What is direct standardisation?
It is a type of adjustment that allows us to compare like-for-like between populations (so comparing strokes, one population might have an older population, so we would look at age-specific incidence)
What is indirect standardisation?
A way of calculating expected mortality rates.
What is the standardised mortality ratio?
can be SIR, standardised incidence ratio where death is replaced with a disease
SMR is the number of observed deaths over expected death, we can times this by 100 to get a larger value but with the same meaning.
