An investigator wants to test whether exposure to secondhand smoke before 1 year of life is associated with development of childhood asthma (defined as asthma diagnosed before 5 years of age). Give two possible study designs.

Question
Study design
asked 2020-11-01
An investigator wants to test whether exposure to secondhand smoke before 1 year of life is associated with development of childhood asthma (defined as asthma diagnosed before 5 years of age). Give two possible study designs.

Answers (1)

2020-11-02
Step 1
Two study design can be used for this scenario:
(i) Two-Sample Independent t-test:
This test is used because:
(a) It is very easy to interpret the output of independent samples.
(b) A small number of subjects for independent t-test samples are required.
(c) T-test enables us to compare the average values of the two data set samples and determine whether the sample subjects come from the same population.
(d) The test gives you all the information you need to know about the population.
Step 2
(ii) Two samples Paired t-test:
This test is used because:
(a) T-test repeated measure design results in small effects since the amount of error from samples is very small.
(b) Only one group is available for testing and this can result in less noise of data.
(c) Only one value from each subject is needed, it requires values of subjects from the two sample groups on a quantitative variable.
(d) Standard software programs that support statistical functions like Microsoft Excel can be used to calculate t-test data.
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