Methodology &Study Designs part2

Disadvantages of correlational study
1.Correlation data represent average exposure level rather than actual individual values. Data on exposure and data on outcome are collected independently.
2.No assurance that persons with exposure (risk factor) of interest are the same ones with outcome (disease) of interest.
3.Inability to link exposure with the disease in particular individual.
Disadvantages of correlational study
1.Correlation data represent average exposure level rather than actual individual values. Data on exposure and data on outcome are collected independently.
2.No assurance that persons with exposure (risk factor) of interest are the same ones with outcome (disease) of interest.
3.Inability to link exposure with the disease in particular individual.•Cross-Sectional studies (prevalence studies or surveys)
It is a study of a group of people at a point in time for the prevalence of a disease or an attribute in a well defined population but data is collected at individual levels. In this study the measurements of exposure and effect are made at the same time .
Survey either:
Population survey= census
Or Sample survey•Cross-Sectional studies (prevalence studies or surveys)
It is a study of a group of people at a point in time for the prevalence of a disease or an attribute in a well defined population but data is collected at individual levels. In this study the measurements of exposure and effect are made at the same time .
Survey either:
Population survey= census
Or Sample survey