Read the following article and answer the questions:

• McConnell R, Berhane K, Gilliland F, London SJ, Islam T, Gauderman WJ, Avol E, Margolis HG, & Peters JM. (2002). Asthma in exercising children exposed to ozone: a cohort study.Lancet, 359(9304), 386-391.

There are 2 parts. In the first part, explain the differences between how prospective and retrospective cohort studies are conducted. In the second part, address the article provided:

• How data are collected in prospective and retrospective cohort studies.
• Each method's strengths and limitations.
• Why an investigator might choose to use one or the other.
• Review the peer-reviewed article reporting on a cohort study. Discuss the above considerations in the report to illustrate the concepts.
• Describe the analysis plan used and explain why they used these analytical methods.
• Imagine you were to conduct the study from the other perspective and describe how you would design the study and conduct the analysis.