Logistic Regression: A Self-learning Text, Third Edition (Statistics in the Health Sciences)

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  1. If the study design had been case-control, what kind of
    measure of association could you have legitimately
    computed from the above models?

  2. For Model 2, compute and interpret the estimated odds
    ratio for the effect of SOC, controlling for SMK and
    SBP? (Again, if you do not have a calculator, just state
    the computations that are required.)

  3. Which of the following general formulae is not
    appropriate for computing the effect of SOC
    controlling for SMK and SBP inModel 1? (Circle one
    choice.) Explain your answer.
    a. exp(bS), wherebSis the coefficient of SOC in model 1.
    b. exp[~bi(X 1 iX 0 i)].
    c. P{exp[bi(X 1 iX 0 i)]}.


Test True or False (Circle T or F)


T F 1. We can use the logistic model provided all the
independent variables in the model are
continuous.
T F 2. Suppose the dependent variable for a certain
multivariable analysis is systolic blood
pressure, treated continuously. Then, a
logistic model should be used to carry out the
analysis.
T F 3. One reason for the popularity of the logistic
model is that the range of the logistic
function, from which the model is derived, lies
between 0 and 1.
T F 4. Another reason for the popularity of the logistic
model is that the shape of the logistic function
is linear.
T F 5. The logistic model describes the probability of
disease development, i.e., risk for the disease,
for a given set of independent variables.
T F 6. The study design framework within which the
logistic model is defined is a follow-up study.
T F 7. Given a fitted logistic model from case-control
data, we can estimate the disease risk for a
specific individual.
T F 8. In follow-up studies, we can use a fitted logistic
model to estimate a risk ratio comparing two
groups whenever all the independent variables
in the model are specified for both groups.

34 1. Introduction to Logistic Regression

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