Question

I am interested in studying a rare disease that also is highly stigmatized and a long incubation period. I am interested in studying multiple exposures in a single study and I am interested in studying the association with those risk factors. Please tell me what study design would be best for this study, what the best recruitment method would be, and what bias i should be concerned about. should the study be retrospective or prospective? would the findings allow for the calculation of the odds Ratio, Risk Ratio or both? Justify your answer fully.  

Answer 1

I will choose Observational Prospective Cohort Study in which an observation is done for till future because these rare diseases like HIV etc has long incubation time and it will take time for the symptoms to appear . The sample will be selected by probability sampling method using simple randomisation ,by using the probability method the chances of bias is nil and every individual will get the chance to get enrolled in the study . The study must be prospective means expecting of a specific thing in the future. The findings will allow for the calculation of both odd ratio and risk ratio.

Risk ratio is the ratio of probability of an outcome in an exposed group to the ratio of probability of an outcome in an unexposed group .

Odd ratio is the measure of association between an exposure and an outcome