Search PubMed⌕ Search

Biomedical subjects

P Fraser

Publications and source records attributed to P Fraser.

98 records · Page 6Linked to original sources
PubMed1979

On the estimation of relative risk from vital statistical data.

A method is described for the determination of a measure of relative risk from vital statistical data. If the frequency of disease in a population is linearly related to the level of exposure to a given factor, then a measure of the relative risk can be estimated from the slope and intercept of the regression line. For example, when the exposure is measured in terms of the proportion of the population exposed to the factor, then the relative risk is equal to (Formula: see text). This offers an indirect but simple and inexpensive method for estimating relative risk. It should be used with caution, particularly where confounding factors may be responsible for the apparent association between disease and factor. Applications of the method to estimate the relative risk of (a) circulatory diseases in women using oral contraceptives and (b) ovarian cancer in women with different average family sizes, both yielded relative risk estimates comparable with those obtained from case-control and prospective studies.

Cardiovascular Diseases↗
PubMed1978

Does pregnancy protect against ovarian cancer?

A clear inverse relation between average completed family size and mortality from ovarian cancer in different populations of women is seen from one country to another; for successive generations of women living within the same country; in married and single women; and in different social, religious, immigrant, and ethnic groups. The findings suggest that pregnancy--or some component of the child-bearing process--protects directly against ovarian cancer. This protection seems to persist throughout life. The more-than-twofold increase in the age-standardised ovarian-cancer death-rate in England and Wales since 1931 can be explained largely by changes in the average completed family size.

Adult↗
PubMedDate not supplied

Methods for age-adjustment of rates.

Different age structures in two populations complicate any comparison of their levels of mortality. Many methods exist which provide death rates or mortality indices adjusted for age and other factors. Such summary measures inevitably lose information, but they are useful for the initial examination of large quantities of data and for the presentation of results. This paper reviews a number of techniques available for producing age-adjusted death rates or mortality indices, emphasizing their historical development. Formulae are given for their calculation. The appropriate context for using each method, and its associated disadvantages are described.

Age Factors↗
PubMedDate not supplied

Spatial learning in transgenic mice expressing human presenilin 1 (PS1) transgenes.

Dominant mutations in the Presenilin 1 gene are linked to an aggressive, early-onset form of familial Alzheimer's Disease (FAD). Spatial memory of transgenic (Tg) mice expressing either mutant (lines Tg(M146L)1, Tg(M146L)76, Tg(L286V)198) or wild type (line Tg(PS1wt)195) human PS1 transgenes was investigated in the Morris water maze (WM) test at 6 and 9 months of age. The results showed that the mutated Tg mice had increased swim speed when compared to non-Tg littermates or Tg PS1 wild type mice. The swim speed difference did not, however, significantly affect the spatial learning in the WM test and all groups showed comparable search paths during training and similar spatial bias during probe trials. When re-tested at 9 months, all mice showed significantly improved learning acquisition of spatial information. The lack of progressive spatial learning impairment in mice expressing the mutated human PS1 transgene in the WM does not preclude impairments in other cognitive tasks but suggests that full phenotypic expression of mutant PS1 alleles may require co-expression of human versions of other AD-associated genes.

Alzheimer Disease↗