Which among the following is the major practical problem in a coho study?
Disadvantages of coho studies: Have to follow large numbers of subjects for a long time. They can be very expensive and time consuming. They are not good for rare diseases. They are not good for diseases with a long latency. Differential loss to follow up can introduce bias.
Differential loss of follow up
Long duration of study
Can be used only for rare conditions
None of the above
Differential loss of follow up