Epidemiological studies design: Descriptive studies
Descriptive research does not fit neatly into the definition of either quantitative or qualitative research methodologies, but instead it can utilize elements of both, often within the same study.
The term descriptive research refers to the type of research question, design, and data analysis that will be applied to a given topic.
Descriptive statistics tell what is, while inferential statistics try to determine cause and effect.
The type of question asked by the researcher will ultimately determine the type of approach necessary to complete an accurate assessment of the topic at hand
Can be sub divided into two study designs, differing in their ability to tie cause to effect and ability to allow comparisons across time or with other groups.
Case report (or case series)
Cross-sectional
Case reports Detailed
presentation of a single case or handful of cases Generally report a new or unique finding e.g.
previous undescribed disease e.g. unexpected link between diseases e.g. unexpected new therapeutic effect e.g. adverse events
Case series
Experience of a group of patients with a similar diagnosis
Assesses prevalent disease
Cases may be identified from a single or multiple sources
Generally report on new/unique condition
May be only realistic design for rare disorders
Cross-sectional
Cross-sectional studies provide a picture of the outcome and the characteristics associated with it, at a specific point in time.
cross-sectional designs focus on studying and drawing inferences from existing differences between people, subjects, or phenomena
Unlike the experimental design where there is an active intervention by the researcher to produce and measure change or to create differences,
focused on finding relationships between variables at one moment in time.
Groups identified for study are purposely selected based upon existing differences in the sample rather than seeking random sampling.
Can estimate prevalence of an outcome of interest because the sample is usually taken from the whole population.
Because cross-sectional designs generally use survey techniques to gather data, they are relatively inexpensive and take up little time to conduct.
Cross-sectional
factor present No Disease
Time point A
factor absent
Time
Study population factor present Disease
factor absent
The end