Public Health Flashcards
1
Q
What is prevalence
A
- Number of population affected by a conditon, burden of a disease
- Number of cases/ number of population
- Point prevalence = number cases at speciric point in time / number pop at same time
- Period prevalence = number cases in specific time period / n populaiton same time period
- Lifetime prevalence = number cases at some point (in their life) has had condition/ n pop (at risk in their lifetime)
2
Q
What is incidence
A
- Number of population newly affected by a condition, risk of disease
- Incidence = number new cases/ number population
- mainly interested a sproportion of people
- Cumulative incidence - nnumber new cases over specific period/npopo (at risk over same time)
- Incidence rate = number of new cases per person time. (N new cases/n pop)/time period.
3
Q
What is a case?
A
- Types: Possible case, Probable case, Confirmed case
- We must define a case to measure it.
- Whatever is chosen, must be explained and justified.
- Defintiion should be: reproducible, clear, specific, measurable,
4
Q
What is population
A
- “population at risk” - those who might develop a specific illness
- Need a clear definition eg, Place, time, demographics, defining event.
- 2 kinds popiulation:
- Fixed - specific criteria - membership permanent eg, attended specific event, born a certain time
- Dynamic - more flexible - membership based on current status eg, lives in specific city,studying at uni now.
5
Q
Methods of counting cases and population?
A
- Count - basic integerm no informative
- Percentage - raw integer into %, provides context and can be changed to fit population count but might change across population sizes
- Ratio - one count divided by another.
- Rate - element of time - how many cases over set period of time
6
Q
Rates and risks used in stats
A
- Prvelaence and incidence
- Probability
- Absoloute risk
- Attributable risk
- Number needed to treat
- Relative risk
- Odds ratio
7
Q
Absolute risk
A
- Prevalence and incidence rates
- Now vs unit time
8
Q
Attributable risk (risk difference, excess risk)
A
- Difference beween two probabilities
- Exposed group vs unexposed group
- Positive intervention = AR reduction
- Negative intervention = AR increase
9
Q
Def of number needed to treat
A
- number of patients you need to treat to prevent one additional bad outcome (or harm if reversed)
- 1/attributable risk reduction
10
Q
What is the absoloute risk of death, attributable risk and NNT
![](https://s3.amazonaws.com/brainscape-prod/system/cm/371/759/303/q_image_thumb.png?1643984690)
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/371/759/303/a_image_thumb.png?1643984704)
11
Q
What os the relative risk and odds ratio?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/371/759/353/q_image_thumb.png?1643984732)
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/371/759/353/a_image_thumb.png?1643984742)
12
Q
working out risks
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/371/759/383/a_image_thumb.png?1643984765)
13
Q
mortality rate and crude mortality rate
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/371/759/398/a_image_thumb.png?1643984789)