## Disease Detectives B/C

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### Re: Disease Detectives B/C

Explain the difference between retrospective cohort and case control studies. Can cohort studies be prospective? Can case control studies be prospective?

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### Re: Disease Detectives B/C

Explain the difference between retrospective cohort and case control studies. Can cohort studies be prospective? Can case control studies be prospective?

Cohort studies can be prospective Case-control cannot be prospective. They can only be retrospective.
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IcsTam
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### Re: Disease Detectives B/C

Explain the difference between retrospective cohort and case control studies. Can cohort studies be prospective? Can case control studies be prospective?

Cohort studies can be prospective Case-control cannot be prospective. They can only be retrospective.
Also, the difference between them is that retrospective cohort is enrolled based on exposure while retrospective case-control is enrolled based on disease status (which obviously cannot be prospective because we wouldn't know disease status beforehand.)
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### Re: Disease Detectives B/C

Explain the difference between retrospective cohort and case control studies. Can cohort studies be prospective? Can case control studies be prospective?

Cohort studies can be prospective Case-control cannot be prospective. They can only be retrospective.
Also, the difference between them is that retrospective cohort is enrolled based on exposure while retrospective case-control is enrolled based on disease status (which obviously cannot be prospective because we wouldn't know disease status beforehand.)
Actually, case-control studies can be prospective. IcsTam, you can go

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### Re: Disease Detectives B/C

Given a 2x2 table, how would you calculate the standard deviation? (qualitative explanation, although if using numbers as an example would help you, then feel free to)
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### Re: Disease Detectives B/C

Given a 2x2 table, how would you calculate the standard deviation? (qualitative explanation, although if using numbers as an example would help you, then feel free to)
Standard deviation of what? A 2x2 table measures categorical data.

(If you mean the sampling distribution of proportions, you can calculate the std dev. of the sampling distribution with $\sqrt{\frac{p(1-p)}{n}}$ or $\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}$ if a proportion is not given.)

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### Re: Disease Detectives B/C

Given a 2x2 table, how would you calculate the standard deviation? (qualitative explanation, although if using numbers as an example would help you, then feel free to)
Standard deviation of what? A 2x2 table measures categorical data.

(If you mean the sampling distribution of proportions, you can calculate the std dev. of the sampling distribution with $\sqrt{\frac{p(1-p)}{n}}$ or $\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}$ if a proportion is not given.)
Oh shoot, I messed up the question, my bad. That's pretty much what I meant. Go for it
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### Re: Disease Detectives B/C

What are the different types of carriers?

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### Re: Disease Detectives B/C

What are the different types of carriers?
Active Carrier - A person who can transmit a disease to others but shows no signs or symptoms
Convalescent Carrier - A person who recently recovered from a disease but can still transmit the disease to others
There may be others but that's all I know.
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### Re: Disease Detectives B/C

What are the different types of carriers?
Active Carrier - A person who can transmit a disease to others but shows no signs or symptoms
Convalescent Carrier - A person who recently recovered from a disease but can still transmit the disease to others
There may be others but that's all I know.