Methods for estimating cohort replacement effects.

G Firebaugh

Home/Archive/PubMed

PubMed · 12317058

Methods for estimating cohort replacement effects.

G Firebaugh

View original source ↗Export metadata ↓

Abstract

The author reexamines the hypothesis developed by Norman Ryder that the birth and death of individuals constitutes a massive process of personnel replacement that holds enormous potential for social change. "In this paper I describe and illustrate six possible ways to estimate cohort (personnel) replacement effects: three based on algebra (Kitagawa's two-component method, forward partitioning, and backward partitioning), and three based on regression (regression standardization, survey metric analysis, and linear decomposition). Assuming monotonic change, regression methods typically are better, because standard algebraic methods are ill suited for analyzing change with regard to birth cohorts that enter or exit during the period studied."

Explore related subjects

Cohort Studies Methods Regression Analysis Research Social Change Statistics as Topic Cohort Analysis Comparative Studies Data Analysis Methodological Studies Research Methodology Statistical Regression Studies World Comparative Study Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

G Firebaugh. 1989. Methods for estimating cohort replacement effects.. https://pubmed.ncbi.nlm.nih.gov/12317058/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2005

Measurement error model for misclassified binary responses.

The article considers regression models for binary response in a situation when the response is subject to classification error. It is also assumed that some of the covariates are unobservable, but measurements on its surrogates are available. Likelihood based analysis is developed to fit the model. A sensitivity analysis is also carried out through simulation to ascertain the effect of ignoring classification error and/or measurement error on the estimation of regression parameters. At the end, the methodology developed in this paper is illustrated through an example.

Cohort Studies↗

PubMed2005

Evaluation of germline PTEN mutations in endometrial cancer patients.

BACKGROUND AND OBJECTIVE: Cowden Syndrome is a rare autosomal dominant disorder characterized by multiple hamartomas, increased risks of breast and thyroid cancers, and possibly endometrial carcinoma. Susceptibility to Cowden syndrome is conferred by germline mutation of the PTEN tumor suppressor gene, and somatic mutations of PTEN are common in sporadic endometrial carcinomas. The aim of this study was to test whether a substantial proportion of endometrial cancers are associated with germline mutations of the PTEN gene, not necessarily in association with clinically overt Cowden syndrome. METHODS: A retrospective cohort of 240 consecutive patients with pathologically confirmed endometrial carcinoma diagnosed at our institution from 1999 to 2002 was ascertained for study. Genomic DNA was isolated from peripheral blood lymphocytes and the entire PTEN coding region and exon-intron junctions were screened for mutations by single strand conformation polymorphism analysis. Potential variants were subjected to direct sequence analysis. RESULTS: No clearly deleterious PTEN sequence variant was identified in this screened cohort of endometrial cancer patients. One patient harbored a 5-bp deletion in the intronic region adjacent to the splice acceptor site of PTEN exon 4, but this variant has been previously classified as a rare polymorphism. CONCLUSIONS: Although these data do not preclude the possibility of an increased risk of endometrial cancer in association with the Cowden syndrome, they indicate that germline PTEN mutations do not account for a significant proportion of genetic attributable risk for endometrial carcinoma.

Cohort Studies↗

PubMed2005

Comparability of dietary patterns assessed by multiple dietary assessment methods: results from the 1946 British Birth Cohort.

OBJECTIVE: The aim of this study is to evaluate the consistency of dietary patterns assessed through the use of a dietary recall and a 5-day food diary. DESIGN: Participants (n = 2265) of a longitudinal study of health and development completed 48-h dietary recall at interview, followed by a 5-day food diary and with the 24 h immediately preceding the interview analysed separately as a 24-h recall. Mean intakes of foods and nutrients were calculated and dietary patterns were assessed using exploratory factor analysis, using the method of principal components. Paired t-tests and correlation coefficients were used to compare the three dietary assessment methods. RESULTS: Five distinct dietary patterns were identified using the food diary and the 48-h recall but were less consistent on the 24-h recall. Correlations between factor scores on the 48-h recall and the food diary (r = 0.13-0.67) were higher than those between the 24-h recall and food diary (r = -0.01-0.59). The recall methods were effective at ranking subjects according to food and nutrient intakes, with the 48-h recall and food diary showing higher correlations in both males and females. CONCLUSIONS: This study indicates that a 48-h recall effectively characterises dietary patterns in British adults when compared to a food diary and ranks participants appropriately with respect to most nutrients and foods and is superior to a single 24-h recall. These results have implications for longitudinal studies where maximising response rates to repeat dietary assessment tools is essential.

Cohort Studies↗