Analysing the difference due to risk and demographic factors for incidence or mortality

Abstract

From an epidemiological and public health perspective there is an interest in quantifying differences in incidence and mortality between either time points, geographical areas or males and females. We propose a method for splitting such a difference in the number of cases/deaths into three components: (1) those due to risk; (2) those due to population structure (i.e. age distribution); and (3) those due to population size. We also propose graphical methods for presenting the results. Three examples are used to illustrate our methodology.

Cancer incidence in France over the 1980–2012 period: Hematological malignancies

“…No indicator for department I d was included because all registries covered the entire period. We partitioned the difference in the total number of cases between 1980 and 2012 into three components using the Bashir method: differences due to the change in the population size; differences due to the change in the population structure (age distribution); differences due to the change in cancer incidence [12].…”

Burden of cancer mortality and differences attributable to demographic aging and risk factors in Argentina, 1986-2011

“…Thus, represents the proportional change between the observed rates in two groups, which is then divided into the proportional change due to population structure and the proportional change due to differences in risk 10 . The RiskDiff web-based application (Registre de Càncer de Catalunya, 2009-2014) was implemented to perform this analysis 9 .…”

“…The year 1986 was used as a baseline and 2011 as a comparison year, along with other intermediate temporal segments (1986-1991; 1991-1996; 1996-2001; 2001-2011). More detail about the algebraic formulation of this can be found in Bashir & Estève 10 .…”

“…These factors are highly relevant given the new context of demographic aging and its potential impact on the development of rational health policies. Therefore, Bashir & Estève 10 proposed a method for partitioning the variation in mortality data between two chronological dates, in terms of demographic variation (population size and population age structure) and differences attributed to changes in risk.…”

Mortalité par cancer en France: le nombre de décès augmente, mais le risque de décès par cancer diminue

“…La méthode est simple et nous l'avons exposée pour les variations entre 1980 et 2000. Elle a été décrite plus en détail dans Bashir et Estève [1].…”