Epidemiology problem solving

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Epidemiology Problem Solving
Question 1 (a)
The survey administered in Western Nebraska is an ecological study. The nature of the questions asked implies that one was seeking to independently and separately establish the rate of being overweight and smoking amongst the participants (sample). The analysis of the data collected in the study can then be used to identify possible cases that need to be studied, like the relationship between smoking and being overweight.
Question 1 (b)
To analyze this data, I will compute the basic statistics (measures of dispersion and measures of central tendency) of each variable (smoking and being overweight) separately. That would give a statistical summary of each of the variables. After that, I will try to establish if there is a relationship between the variables or not by computing the correlation between being overweight and smoking.
Question 2 (a)
The kind of study in this question is a case-control study. In establishing the sample, the study demanded a specified population pointing to a specific case. For this study, the case was stomach ulcers, and the established comparison group (controls) is individuals without stomach ulcers. Both the controls and the case group are evaluated of their past exposure to coffee he researchers sought to establish any connection between coffee and stomach ulcers and therefore, the goal of the study is already defined and tied to the case.
Question 2 (b)
An odds ratio gives a comparison between the possibility of exposure between the case and the controls.

Case population = 1000
The case exposed to coffee = 300
Odds of exposure = 300/1000 = 0.3
Control population = 800
Control exposed to coffee = 50
Odds of exposure = 50/800 = 0.0625
The odds ratio is given by dividing the odds of exposure for the case by that of the controls
= 0.3/0.0625
= 4.8
Odds ratio = 4.8
This odds ratio is greater than 1 and therefore confirms that coffee is associated with stomach ulcers according to the data from the study.
Question 3 (a)
The appropriate measure of association for the mentioned study is the odds ratio. The case (having cervical cancer) is determined as is the control (not having cervical cancer) and the risk factor (Having HPV antibodies). The odds ratio is a measure of association that establishes any connection between the two variables through the evaluation of the risk factor.
Question 3 (b)
Case population = 350
Odds of exposure = 90/100 = 0.9
Control population = 500
Odds of exposure = 63/100 = 0.63
The odds ratio is given by dividing the odds of exposure for the case by that of the controls
= 0.9/0.63
= 1.4285714286 = 1.43
Odds ratio = 1.43
This odds ratio is greater than 1 and therefore confirms that testing positive for HPV antibodies has a relation to having cervical cancer as per the data from the study.
Question 4 (a)
This study in this question is a cohort study. In it, a group of people (500) from a community that lived near the Three-Mile Island has to be followed over a period of 23 years. Another group of people (400) from the same community but living elsewhere but near the 3M Island is also to be followed by the same amount of time. The goal is to see if they developed leukemia or not and the risk factor is living close to the 3M Island three months before the accident that occurred there. The outcomes of developing leukemia are compared between the two groups is then compared. (“Study Design 101 – Cohort Study”).
Question 4 (b)
Relative risk is given by comparing the risk of developing the disease in the group that is exposed to that that is not exposed.
Risk of developing the disease in the exposed group:
= 15/500 = 0.03
Risk of developing the disease in the unexposed group:
= 10/400 = 0.025
Relative Risk (RR) = 0.03/0.025
= 1.2
The relative risk of 1.2 portrays an increased risk of the disease to those that were exposed to the risk factor.
Works Cited
“Study Design 101 – Cohort Study.” Himmelfarb.gwu, himmelfarb.gwu.edu/tutorials/studydesign101/cohorts.html. Accessed 14 Apr. 2018.