Biomaterial Database

[Comparison of observed and expected person-years: a simulated approach]. 1990

D Luce, and A Leclerc, and J F Chastang, and M Goldberg

INSERM Unité 88, Paris.

In Epidemiology, no simple test is available for comparing an observed number of exposed person-years with an expected number. The number of person-years is a sum of lengths of stays which is not normally distributed under the null hypothesis. A method is proposed and an example is given. The objective was to study in the French territory of New-Caledonia the relationship between past places of living and occurrence of respiratory cancers. The total observed number of person-years in a zone, among cases, was compared to an expected distribution, based on censuses and controlling for two confounding factors, period of stay and ethnic group. Different methods are compared: a test based on a simulated distribution, and parametric approaches with normality assumption. If the number of cases is small, the simulation test seems to be the best approach.

UI	MeSH Term	Description	Entries
D009510	New Caledonia	A group of islands in Melanesia constituting a French overseas territory. The group includes New Caledonia (the main island), Ile des Pins, Loyalty Island, and several other islet groups. The capital is Noumea. It was discovered by Captain Cook in 1774 and visited by various navigators, explorers, and traders from 1792 to 1840. Occupied by the French in 1853, it was set up as a penal colony 1864-94. In 1946 it was made a French overseas territory. It was named by Captain Cook with the 5th and 6th century A.D. Latin name for Scotland, Caledonia. (From Webster's New Geographical Dictionary, 1988, p830 & Room, Brewer's Dictionary of Names, 1992, p375)
D012142	Respiratory Tract Neoplasms	Tumors or cancer of the RESPIRATORY SYSTEM.	Respiratory Neoplasms,Respiratory System Neoplasms,Neoplasm, Respiratory,Neoplasm, Respiratory System,Neoplasm, Respiratory Tract,Respiratory Neoplasm,Respiratory System Neoplasm,Respiratory Tract Neoplasm
D004777	Environment	The external elements and conditions which surround, influence, and affect the life and development of an organism or population.	Environmental Impact,Environmental Impacts,Impact, Environmental,Impacts, Environmental,Environments
D004812	Epidemiologic Methods	Research techniques that focus on study designs and data gathering methods in human and animal populations.	Epidemiologic Method,Epidemiological Methods,Methods, Epidemiologic,Epidemiological Method,Method, Epidemiologic,Method, Epidemiological,Methods, Epidemiological
D005006	Ethnicity	A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.	Ethnic Groups,Nationality,Ethnic Group,Nationalities
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
D015986	Confounding Factors, Epidemiologic	Factors that can cause or prevent the outcome of interest but are not intermediate variables of the factor(s) under investigation.	Confounding Factor, Epidemiologic,Confounding Factors, Epidemiological,Confounding Factors, Epidemiology,Confounding Variables,Confounding Variables, Epidemiologic,Confounding Variables, Epidemiological,Confounding Factor, Epidemiological,Confounding Factor, Epidemiology,Confounding Variable,Confounding Variable, Epidemiologic,Confounding Variable, Epidemiological,Epidemiologic Confounding Factor,Epidemiologic Confounding Factors,Epidemiologic Confounding Variable,Epidemiologic Confounding Variables,Epidemiological Confounding Factor,Epidemiological Confounding Factors,Epidemiological Confounding Variable,Epidemiological Confounding Variables,Epidemiology Confounding Factor,Epidemiology Confounding Factors,Variable, Confounding,Variable, Epidemiologic Confounding,Variable, Epidemiological Confounding,Variables, Confounding,Variables, Epidemiologic Confounding,Variables, Epidemiological Confounding