Human papilloma virus (HPV) is a group of more than 150 related viruses. They are contagious and can spread from person to person via intimate skin-toskin contact. The virus is most commonly spread through sexual contact. Some strains of HPV can cause cancer, but there is a vaccine for the strains that cause most of these cancers.
In other words, there is a vaccine that can prevent about 91% of HPV-related cancers. Resources CDC. (2016a). “What is HPV?” Retrieved from https://www.cdc.gov/hpv/parents/whatishpv.html CDC. (2016b). “HPV vaccines: Vaccinating your preteen or teen.” Retrieved from https://www.cdc.gov/hpv/parents/vaccine.html.
Then, in your initial post, address the following:
1. Create a research question to investigate HPV.
2. Explain whether you would use an observational or experimental design to investigate the research question. Be sure to justify your choice.
Observational studies look for associations between risk factors and health outcomes. This is accomplished by observing behavior. The investigator does not control the independent variable(s). Because we have been discussing infectious disease, we will use an outbreak as example. During an outbreak of an infectious disease, a case-control study is one type of observational study that might be used. The term case refers to individuals who have the disease, and the term control refers to a population that does not have the disease. Cases and controls are identified in various ways that you will read about in this module. The important thing about this type of study is that the cases are already sick, or have been sick, when they are identified. Investigators are then able to ask these individuals about behaviors (i.e., exposures) that may have contributed to developing the sickness. In the instance of a foodborne outbreak, the individuals may be asked where they ate in the last week, what they ate, how much of the specific food they ate, and so on. Investigators will compare the answers from the cases to the answers from the controls. This information can then be used to develop odds ratios. These calculations assist in narrowing down information and allowing epidemiologists to make informed estimates of which food item(s) were responsible for the outbreak. The key to remember with observational studies is that the cases are already sick. The researchers did not give them anything that may or may not make them sick. Because of this limitation, observational studies cannot prove causality.
In an experimental study, the investigators control the independent variables to see what effect they have on a dependent variable. This type of study examines causation, which is a change in the independent variable resulting in a change in the dependent variable. New medications are a good example of an experimental study. A pharmaceutical company may be interested in a newly developed Alzheimer’s medication (independent variable) that was developed to slow cognitive decline (dependent variable). To do this, they recruit 60 people at a similar stage of Alzheimer’s disease and randomly divide them into groups—randomness is a key element. Let us say they were divided into two groups of 30. One group would receive the new medication and the other would receive a placebo (a sugar pill that looks exactly like the medication). The people in the two groups do not know which group they belong to. In other words, participants do not know if they are receiving the new medication or a placebo. The researchers then study the individuals over a specified amount of time and compare the outcomes from the two groups. If the medication works, it is expected that the group receiving the medication will have a better outcome (slower cognitive decline) than the group receiving the placebo. In this example, the researchers controlled the independent variable (medication) to see the effect on the dependent variable (cognitive decline). This is a randomized, placebo-controlled trial. It is an experimental study because the researchers controlled the independent variable.