Concept explainers
A study was conducted of genetic and environmental influences on cholesterol levels. The data set used for the study were obtained from a twin registry in Sweden [10]. Specifically, four populations of adult twins were studied: (1) monozygotic (MZ) twins reared apart, (2) MZ twins reared together, (3) dizygotic (DZ) twins reared apart, and (4) DZ twins reared together. One issue is whether it is necessary to correct for gender before performing more complex genetic analyses. The data in Table 8.17 were presented for total cholesterol levels for MZ twins reared apart, by gender.
Table 8.17 Comparison of mean total cholesterol for MZ twins reared apart, by gender
Note: n = number of people (e.g., for males, 22 pairs of twins = 44 people) the cholesterol levels within each sample consist of independent observation.
If we assume (a) serum cholesterol is
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- What is meant by the sample space of an experiment?arrow_forwardWhat is an experiment?arrow_forwardAn important issue is whether there are racial differences in hypertension among children. We define hypertension as being above the 95th percentile for either systolic blood pressure (SBP) or diastolic blood pressure (DBP) among children of the same age, height, and sex. Since some of the children were observed at multiple visits, a GEE model was run of hypertension on ethnic group. There were three ethnic groups considered: Caucasian, African American, and Hispanic. The results among boys are given in Table 13.54. TABLE 13.54 Relationship between hypertension and ethnic group among 27,009 boys in the Pediatric Task Force Data Variable Regression Coefficient SE Intercept -2.07 0.026 African American 0.049 0.041 Hispanic 0.328 0.059 What is the estimated OR for hypertension comparing Hispanic boys vs. Caucasian boys? (Call this OR1.) What is a 95% CI for this estimate?arrow_forward
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