Improving power with repeated measures: diet and serum lipids
نویسندگان
چکیده
منابع مشابه
Repeated measures with zeros.
Consider repeated measures data with many zeros. For the case with one grouping factor and one repeated measure, we examine several models, assuming that the nonzero data are roughly lognormal. One of the simplest approaches is to model the zeros as left-censored observations from the lognormal distribution. A random effect is assumed for subjects. The censored model makes a strong assumption a...
متن کاملRepeated Measures
Repeated measures refer to the observations taken on the same subject (plant, animal, person, etc). There is usually a variation among the subjects, which is modeled by random effects. Here is an example. A completely randomized design with a single factor (with fertilizer or without). Each treatment is applied to three plants and the root length of each plant is measured on five occasions (wee...
متن کاملRepeated measures.
A repeated-measures design is one in which multiple, or repeated, measurements are made on each experimental unit. The experimental unit could be a person or an animal, and repeated measurements might be taken serially in time, such as in weekly systolic blood pressures or monthly weights. The repeated assessments might be measured under different experimental conditions. Repeated measurements ...
متن کاملDiet and the Blood Lipids
There is in general a fair agreement between workers as regards the lipid levels of the blood, but there are occasional groups of “normal” values for the lipids, both of whole blood and plasma, which are out of line, and even in a single series occasional widely discrepant values may be found. Inadequacy of methods, while undoubtedly responsible for some of the differences, does not account for...
متن کاملSerum Lipids and Atherosclerosis
That hyperlipemia may be responsible for atherosclerosis has long been hypothecated on the grounds of what might be termed circumstantial evidence. The first experimental proof of this concept was provided by Anitschkow's demonstration in 1913 that atheroma can be produced in rabbits by feeding cholesterol. In recent years similar lesions have been induced by similar methods in five other speci...
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ژورنال
عنوان ژورنال: The American Journal of Clinical Nutrition
سال: 1998
ISSN: 0002-9165,1938-3207
DOI: 10.1093/ajcn/67.5.934