@article{3051536,
    title = "Population density and childhood leukaemia: Results of the EUROCLUS
study",
    author = "Alexander, FE and Boyle, P and Carli, PM and Coebergh, JW and Ekbom, A and and Levi, F and McKinney, PA and McWhirter, W and Michaelis, J and and Peris-Bonet, R and Petridou, E and Pompe-Kirn, V and Plesko, I and and Pukkala, E and Rahu, M and Stiller, CA and Storm, H and Terracini, B and and Vatten, L and Wray, N and EUROCLUS Project",
    journal = "EUROPEAN JOURNAL OF CANCER",
    year = "1999",
    volume = "35",
    number = "3",
    pages = "439-444",
    publisher = "Elsevier Sci Ltd, Exeter, United Kingdom",
    doi = "10.1016/S0959-8049(98)00385-2",
    keywords = "childhood leukaemia; clustering; population density; infections;
epidemiology; Poisson regression",
    abstract = "The EUROCLUS study assembled incidence data for 13 551 cases of
childhood leukaemia (CL) diagnosed between 1980 and 1989 in 17 countries
(or regions of countries). These were referenced by location at
diagnosis to small census areas of which there were 25 723 in the study
area. Population counts, surface area and, hence, population density
were available for all these small areas. Previous analyses have shown
limited extra-Poisson variation (EPV) of case counts within small areas;
this is most pronounced in areas of intermediate population density
(150-499 persons/km(2)). In this study, the data set was examined in
more detail for evidence that variations in incidence and EPV of CL are
associated with population density. Incidence showed a curvilinear
association with population density and was highest in areas which were
somewhat more densely populated (500-750 persons/km(2)), where the
incidence rate ratio relative to areas having greater than or equal to
1000 persons/km(2) was 1.16 (95% confidence interval 1.07-1.26) and the
P value for quadratic trend across eight strata of population density
was 0.02. Incidence in these areas is uniformly elevated and showed no
evidence of heterogeneity (i.e. EPV). Statistically significant evidence
of EPV was evident amongst some of the areas previously classified as
intermediate density areas (specifically, those with a density of
250-499 persons/km(2), P < 0.001 for CL). These results were interpreted
in terms of the current aetiological hypotheses for CL which propose
that exposure to localised epidemics of one or more common infectious
agent may contribute to the development of leukaemia. They suggest that
such epidemics arise regularly in moderately densely populated areas and
also sporadically in areas which are somewhat less densely populated.
Although other interpretations are possible, these results may assist:
in the identification of characteristics which infectious agents must
possess if direct or indirect causes of CL. (C) 1999 Elsevier Science
Ltd. All rights reserved."
}