Introductory Biostatistics
low-up times because they were enrolled sequentially at di¤erent times. Times in weeks were: 6-MP group:6, 6, 6, 7, 10, 13, 16, ...
Note: An SAS program would include these instructions: PROC PHREG DATA = CANCER; MODEL WEEKS*RELAPSE(0) = DRUG TESTEE; TESTEE = ...
11.5.1 Model Consider a case–control design and suppose that each person in a large popu- lation has been classified as exposed ...
similar values for the important confounding variables. The simplest example of pair-matched data occurs with a single binary ex ...
statistic, z¼ n 10 n 01 ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi n 10 þn 01 p is compared to percentiles of the s ...
California from 1971 to 1975, each disease person was matched withR¼ 4 controls who were alive and living in the community at th ...
m¼Mþ1 [similar toð;Þandðþ;þÞcells in the 1:1 matching design] will be ignored. If we fix the numbermof exposed persons in each ...
The result turns out to be, quite simply, dORMH¼ P ðMmþ 1 Þn 1 ;m 1 P mn 0 ;m and the Mantel–Haenszel estimate has been used w ...
The Mantel–Haenszel estimate for the odds ratio is dORMH¼ ð 4 Þð 4 Þþð 3 Þð 17 Þþð 2 Þð 11 Þþð 1 Þð 9 Þ ð 1 Þð 6 Þþð 2 Þð 3 Þþð ...
w^2 ES¼ 4 ^1 210 þ 17 ^2 520 þ 11 ^3 512 þ 9 ^4 510 þ 1 ^1 41 þ 3 ^2 43 2 1 25 ½ð^1 ...
ered within five days of the case in the same hospital. The risk factors of inter- est are the mother’s bleeding in this pregnan ...
TABLE 11.14 Matched Set Case Mother’s Weight Hypertension Smoking Uterine Irritability 1 1 130 0 0 0 0 112 0 0 0 0 135 1 0 0 0 2 ...
L¼ YN i¼ 1 expðbxiÞ expðbxiÞþ Pmi j expðbxijÞ from which we can obtain an estimate of the parameterb. The likelihood function ab ...
The odds ratio due to a 1-unit increase ifXis continuous (X¼xþ 1 versusX¼x). Afterbb^and its standard error have been obtained ...
(if the covariate under investigation is on a continuous scale). Of course, application of the conditional logistic model is sti ...
actions). Therefore, to provide a more comprehensive analysis, it is very desir- able to consider a large number of factors and ...
exp½bb^iG 1 :96 SEðbb^iÞ These results are necessary in the e¤ort to identify important risk factors in matched designs. Of cou ...
likelihood ratio test, Wald’s test, and the score test. All three statistics are pro- vided by most standard computer programs s ...
computer-packaged programs such as SAS. In performing this test, we refer the value of thezscore to percentiles of the standard ...
type of test to check for linearity. It can also be used to check for a single product representing an e¤ect modification. Examp ...
«
17
18
19
20
21
22
23
24
25
26
»
Free download pdf