Question

Instead, consider the setting up an Observational Study. read about and consider the three types of studies: Cohort, Case-control and Crossectional Studies. Choose one of these three approach-es, and briefly describe how you would do it. Be sure to say what your comparison group would be.

Answer 1

Answer1) The descriptive and analytical studies are often called as the 'observational studies '

a)setting up an observational studies-

The study can be done on the caries, fluorine hypothesis in areas of the natural fluoride water constitutes the "analytical phase" .

These studies are concerned with the observation of the distribution of the disease events in the human population and identification of the characteristics of the disease with which it is associated.

There are various steps that are involved in the descriptive study that are-

1)defining the population to be studied .

2)defining the disease under study

3)describing the disease in terms of the a)timeb)placec)person

4)measurement of the disease

5)comparing with the known indices

6)formulating an ecological hypothesis

crosssectional studies can be used as an approach for the study design including a simple random sampling -

cross sectional can also be called as the prevalence studies and where a set of individuals are chosen who will represent a sample or of the special sub groups for example school children, workers in a particular community .

1)screening camps for school children ageing 15 years old can be conducted to establish the prevalence of the dental fluorosis and dental caries .

2)so we have taken a certain age group for the study design and then there should be a recording of the intra oral findings and clinical history taking of the patient regarding the source of the drinking water.

3)identifying the risk factors associated with the disease and the we can collect the data and subject to analysis between those children with fluorosis against those without fluorosis.

4)calculating the incidence of the disease which will provide a valuable information. An independent sample test can be calculated comparing the average caries in children with fluorosis with those without it.

The essence of the any epidemiological study is make comparing and comparisons group between the different populations and the and subgroups of the same population.

selection of the comparisons group -

there are many ways to assemble the comparison groups -

A)internal comparisons :

In some of the no outside comparisons groups are required .they can be within like for knowing effected students we can take the age of the student from 7 years to 15 years they are accordingly to the level of explosure to risk.the group can be then compared

B)external comparisons - when the degree of explosure is not available, it is better to evaluate with the experienced groups.

And the end could be follow up procedures

A) periodic clinical examination of the each of the member of the cross sectional study.

B) reviews of the records

C)routine surveillance of records and telephone calls.