What is Epidemiology?
Prep Assignment for Part 1: Epidemiology Due: Tuesday, 9/22 by 10:15am on Canvas Overview The overall goal of this assignment is to apply the concepts learned regarding epidemiological study types by having you design your own studies. You will use this worksheet to write a short paper on epidemiology for Part 1 of your Cancer Portfolio. Step 1: Do a little research online to find out what lifestyle factors or environmental exposures, if any, are thought to be linked with your assigned cancer type. List them below, and note your sources. Note: age and genes are NOT lifestyle/environmental exposures. Cancer type: Colon Cancer (Colorectal cancer) Lifestyle Factors or Exposures: Source(s): Step 2: Using the questions below, design two epidemiological studies to test the link between one of these lifestyle/environmental factors and your cancer type. If your cancer type does not have any known or suspected lifestyle or environmental exposures, think of something that might be a risk factor (there doesnt need to be any prior evidence supporting a link; jut use logical reasoning) and design your studies to investigate it. What lifestyle factor or environmental exposure will you be investigating? What is your predicted correlation? Design a Prospective Cohort Study to answer your question Be specific and precise and answer each part of the questions. You may write a short paragraph or use bullet points to answer each question. How will you recruit people to be in your cohort study? How many people will you need to recruit? How do you ascertain this? (Hint: You will need to know what your cancer incidence rate is- *see below – in order to reasonably answer this question. Use your incidence rate to explain your reasoning. What factors will you track within your cohort? Hint: a good study would attempt to account for obvious confounding variables. How long will your study last? Explain your reasoning. Design a Prospective Case-Control Study to answer your question Be specific and precise. You may write a short paragraph or use bullet points to answer each question. Who will you recruit to be in your case-control study and how will you go about it? How many people will you need to recruit (again, think about incidence rate)? For a case-control study, what types of retrospective questions will you ask the participants in the study? Hint: a good study would attempt to account for obvious confounding variables. How might the issue of recall bias affect your interpretation of your results? In your answer, be sure to clearly illustrate your understanding of recall bias. Comparing study design (cohort or case control) pros and cons How will Recruitment and Retention differ between your prospective cohort and your retrospective case-control study? Discuss the pros and cons for your two types of studies. Will one type of study have less Potential Biases than the other? Why? Will one type of study have a higher cost than the other? Do a brief Cost Comparison taking into account sample size and length of study, and discuss whether either or both seem logistically doable or not. *Incidence rates are a measure of how rare a disease is within a population. They are usually expressed as some number per 100,000 people, or sometimes as a percentage of the population. If your cancer type is very rare, then you will need to have a very large sample size. For example, if your cancer type occurs in 4 out of 100,000 people, youll need a sample size of at least 1 million people to follow, in order to see 40 cases. Youll also need to tailor your sample size to the population from which you will be recruiting subjects; some countries have higher incidence rates for certain types of cancers. If you are recruiting from the US population, use the US incidence rate; if you are recruiting from a different country, use the incidence rate specific to that country.
