ASSIGNMENT #2 – Biostatistics (48 points)

1) Pulmonary Disease

Book Problems: 2.23 briefly discuss each the results for each variable (5 pts.), 2.24 discuss important findings (4 pts.), 2.25(3 pts.)

Data Files:FEV.JMPFEV.lsp

2) Diabetes Data

These data are courtesy of Dr John Schorling, Department of Medicine, University of Virginia School of Medicine.

Data File: Diabetes.JMP

The data consist of 19 variables on 403 subjects from 1046 subjects who were interviewed in a study to understand the prevalence of obesity, diabetes, and other cardiovascular risk factors in central Virginia for African Americans. According to Dr John Hong, Diabetes Mellitus Type II (adult onset diabetes) is associated most strongly with obesity. The waist/hip ratio may be a predictor in diabetes and heart disease. DM II is also agssociated with hypertension - they may both be part of "Syndrome X". The 403 subjects were the ones who were actually screened for diabetes. Glycosolated hemoglobin > 7.0 is usually taken as a positive diagnosis of diabetes. For more information about this study see
Willems JP, Saunders JT, DE Hunt, JB Schorling: Prevalence of coronary heart disease risk factors among rural blacks: A community-based study. Southern Medical Journal 90:814-820; 1997
and
Schorling JB, Roach J, Siegel M, Baturka N, HuntDE, Guterbock TM, Stewart HL: A trial of church-based smoking cessation interventions for rural African Americans. Preventive Medicine 26:92-101; 1997.

Variable Descriptions

Variable Name / Labels
id / Subject ID
chol / Total Cholesterol
stab.glu / Stabilized Glucose
hdl / High Density Lipoprotein
ratio / Cholesterol/HDL Ratio
glyhb / Glycosolated Hemoglobin
location / Buckingham or Louisa
age / Age of patient
gender
height
weight
frame / Body frame size (small, medium, large)
bp.1s / First Systolic Blood Pressure
bp.1d / First Diastolic Blood Pressure
bp.2s / Second Systolic Blood Pressure
bp.2d / Second Diastolic Blood Pressure
waist / Waistline
hip / Hip measurement
time.ppn / Postprandial Time when Labs were Drawn

a) From the discussion what is the population of interest to the researchers in this study?

(1 pt.)

b) Is the sample used likely to be representative of that population? Explain. (2 pts.)

Assessment of introductory statistics knowledge – I believe that all of you, in previous classes, have learned how to conduct and interpret the results from inferential procedures that could be used to investigate the following questions. Discuss the results in such a way that the medical researchers (who are not statisticians) will understand

c) Use appropriate statistical methods to compare the mean waistline of diabetics to non-diabetics in this population and discuss the results. (4 pts.)

d) Use appropriate statistical methods to compare the first systolic blood pressure reading to the second systolic blood pressure reading for these patients and discuss the results. (4 pts.)

e) Complete the table below and provide an appropriate graphic showing the results visually. Briefly discuss the results. (4 pts.)

Body Frame Size / % Diabetic

Looking ahead a bit…

f) Estimate how many times more likely is a large frame person to be diabetic than a person with a small frame. Does your answer change if you consider gender? Explain. (3 pts.)

Read All of Chapter 3 then do the problems below...
Chapter 3 Book Problems:
Mental Health
3.17 - 3.28 (16 pts.)
Pulmonary Disease
3.52 - 3.56 (6 pts.)