Practice
Exercises
True or False (Circle T or F)T F 1. In a case-control study, category pair-matching
on age and sex is a procedure by which, for each
control in the study, a case is found as its pair to
be in the same age category and same sex cate-
gory as the control.
T F 2. In a follow-up study, pair-matching on age is a
procedure by which the age distribution of
cases (i.e., those with the disease) in the study
is constrained to be the same as the age distri-
bution of noncases in the study.
T F 3. In a 3-to-1 matched case-control study, the num-
ber of observations in each stratum, assuming
sufficient controls are found for each case, is
four.
T F 4. An advantage of matching over not matching is
that a more precise estimate of the odds ratio
may be obtained from matching.
T F 5. One reason for deciding to match is to gain
validity in estimating the odds ratio of interest.
T F 6. When in doubt, it is safer to match than not to
match.
T F 7. A matched analysis can be carried out using a
stratified analysis in which the strata consists of
the collection of matched sets.
T F 8. In a pair-matched case-control study, the Man-
tel–Haenszel odds ratio (i.e., the MOR) is equiv-
alent to McNemar’s test statistic (XY)^2 /
(XþY). (Note:Xdenotes the number of pairs
for which the case is exposed and the control is
unexposed, andYdenotes the number of pairs
for which the case is unexposed and the control
is exposed.)
T F 9. When carrying out a Mantel–Haenszel chi-square
test for 4-to-1 matched case-control data, the
number of strata is equal to 5.
T F 10. Suppose in a pair-matched case-control study,
that the number of pairs in each of the four
cells of the table used for McNemar’s test is
given byW¼50,X¼40,Y¼20, andZ¼100.
Then, the computed value of McNemar’s test
statistic is given by 2.- For the pair-matched case-control study described in
Exercise 10, letEdenote the (0, 1) exposure variable
and letDdenote the (0, 1) disease variable. State the
420 11. Analysis of Matched Data Using Logistic Regression