Question

describe, briefly, the challenges to the validity of study designs; relate these challenges to case-control studies, cohort studies, and randomized controlled trials.

Answer 1

Validity in research means how well the study findings measure truly represent the phenomenon to be measured. There are many challenges to the validity of the study designs such as:

# population validity

# ecological validity

# more intervention treatment interference

# carry over effect

The challenge of validity in cohort studies are as follows:

# faulty measurement devices

# hawthorne effect were by sample knows how to behave for the study

# distortion resulting from intervention

# information bias like misclassification of the samples

# exposure of interest and outcome

# differential loss to follow up

The challenge of validity in case control studies are as follows :

# sample selection bias

# confounder affected with exposure

# confounder affected with outcome

# interviewer bias

# recall bias

The challenge of validity in randomised control trials are:

# withdrawl bias

# challenging trials

# conflict of interest

# ethical

# blindfold issues