Question

If you wanted to study the risk factors for a rare and mostly unknown form of cancer (CancerM) in a small community (population = approx10,000) in Alaska, where the cancer mainly impacts people aged 30-50 years old (both males and females), but there is some variability. Which research design is best to use: cross sectional, case control, or cohort (retrospective or prospective)?

Answer 1

Case control study will be suitable for studying a small population for a rare disease. Since, not much is known about the this disease, case control study will be the right choice.

in case control study design, the study of rare disease or preliminary study without much knowledge about the association or risk factor is possible. This is an observational study of people with the disease of interest and a suitable control.

in case control studies, both exposure and outcomes a have already occurred. This study focuses on effect and goes backwards towards causation.

case-control study are less costly and shorter in duration.

In this study design, the population of Alaska can be scanned for people for this particular rare type of cancer. Further it can be clarified if the people who developed this types of cancer falls between the age of 30-50. This will give a preliminary idea about the disease and its causation.

Further, cohort study design can be used for detailed studies.

we cannot do a cohort study because it involved tracking people who are already in a risk factor category but do not show the rare disease over time. (We do not know what are the risk factors for this case. We have limited information.)The people will then be tested for the diesease development timely. This is more expensive, time consuming and requires a good knowledge about the disease. It is not suitable for an unknown rare disease .

cross-sectional studies needs data from the entire population whereas case control studies focuses on people with the disease. Cross-sectional studies are descriptive in nature. They are expensive and not suitable for rare disease.they are used to test prevalence of acute or chronic disease in a population.