5 epidemiology questions with statistic calculation

Epidemiology Question 1

(Total 10 pts.)

Please draw a 2×2 table adding the following descriptors:

o Exposure

o No-exposure

o Diseased

o Healthy

…and add the letters “A”, “B”, “C” and “D” to the four boxes (4 pts.):

 

Referring to your 2×2 table above, give the formula that needs to be used to calculate the values listed below. Use the letters A, B, C and D in the numerator and denominator in your formulas:

 

Relative Risk (2 pts.):

 

Odds Ratio (2 pts.):

 

Exposure Rate (2 pts.):

 

Question 2 (Total 12 pts.)

Draw flow diagrams for the three study designs listed below and list the advantages and disadvantages of each.

o Case-control study (2 pts.):

Advantages (1 pt.) Disadvantages (1 pt.):

 

o Cohort study (2 pts.):

 

Advantages (1 pt.): Disadvantages (1 pt.):

 

o Experiment (2 pts):

 

Advantages (1 pt.): Disadvantages (1 pt.):

 

Epidemiology Question 3

(Total 12 pts.)

Please draw a 2×2 diagnostic test table adding the following descriptors: o Test outcome – positive

o Test outcome – negative

o Patient has the disease

o Patient does not have the disease

o True positive

o False positive

o True negative

o False negative

 

….. and add the letters “A”, “B”, “C” and “D” to the four boxes (8pts.):

 

Referring to your 2×2 table drawn above, give the formulas for calculating the parameters listed below. Use the letters A, B, C and D in the numerators and denominators:

 

Sensitivity (2 pts.):

 

Specificity (2 pts.):

 

Epidemiology Question 4 (Total 4 pts.)

Briefly explain the potential advantages and disadvantages associated with the following outcomes in a community diagnostic screening test:

 

False positive (2 pts.):

 

False negative (2 pts.):

 

Epidemiology Question 5 (2 pts.)

Briefly explain why randomization in test subject assignment to either the exposure group or the “control” group in an experimental design is important.