Zusammenfassung der Ressource
Other
studies
- Case control studies
- examine the association of disease with past
exposure(s) (e.g. abuse as a child and severe
depression as an adult).
- can be completed quickly (unlike cohort studies where
people often need to be followed for several years to see if
certain conditions develop)
- reasonably economical, and the study
population can be small
- used to study relatively rare diseases.
- identify the cause of food-related illness
after customers have eaten in a restaurant
(i.e. What did the people who got sick eat
[cases], that the people who did not get sick
[controls] refrained from eating?).
- Results expressed as
- results are expressed as odds ratios (OR).
- estimate the increased (or decreased)
risk of disease for those in the exposed
group
- Order of inquiry
- disease status is measured first, then participants are
followed up (backwards in time) until exposure status is
established, and the two groups are compared.
- E.g
- 1.Are oral contraceptives
associated with breast
cancer?
- Cross sectional studies
- provide data from a single 'snapshot'
in time and are often used to study
prevalence (current disease or
outcome)
- used to measure variables such as health-related
attitudes and behaviours in a population or sample
of the population.
- Analytical cross-sectional studies/surveys
- 'getting the temporal direction of cause-effect
correct', and cross-sectional studies cannot, in
themselves, establish this.
- does excessive television
watching cause obesity, or
are these two variables
simply associated?
- either the entire population or a
sample from that population is
selected
- individuals' data are collected using records
or a questionnaire (or some type of measuring
instrument) that focuses on the area of
interest.
- Examples
- 1.What is the prevalence of
stroke in Victoria in 2012?
- 2.Are young
people aware of,
and involved in,
tobacco marketing?
- Results
- expressed in terms frequencies and proportions (%)
- statistical approaches like Chi-square (x2)and p-values.