title: RiskDiff: a web tool for the analysis of the difference due to risk and demographic factors for incidence or mortality data.
abstract: BACKGROUND
  Analysing the observed differences for incidence or mortality of a particular disease between two different situations (such as time points, geographical areas, gender or other social characteristics) can be useful both for scientific or administrative purposes. From an epidemiological and public health point of view, it is of great interest to assess the effect of demographic factors in these observed differences in order to elucidate the effect of the risk of developing a disease or dying from it. The method proposed by Bashir and Estève, which splits the observed variation into three components: risk, population structure and population size is a common choice at practice.
  
  
  RESULTS
  A web-based application, called RiskDiff has been implemented (available at http://rht.iconcologia.net/riskdiff.htm), to perform this kind of statistical analyses, providing text and graphical summaries. Code from the implemented functions in R is also provided. An application to cancer mortality data from Catalonia is used for illustration.
  
  
  CONCLUSIONS
  Combining epidemiological with demographical factors is crucial for analysing incidence or mortality from a disease, especially if the population pyramids show substantial differences. The tool implemented may serve to promote and divulgate the use of this method to give advice for epidemiologic interpretation and decision making in public health.
authors.affiliation: Catalan Cancer Registry, Catalan Institute of Oncology, Barcelona, Catalonia. joan.valls@iconcologia.net
authors.forename: Joan
authors.initials: J
authors.lastname: Valls
authors.forename: Ramon
authors.initials: R
authors.lastname: Clèries
authors.forename: Jordi
authors.initials: J
authors.lastname: Gálvez
authors.forename: Victor
authors.initials: V
authors.lastname: Moreno
authors.forename: Rosa
authors.initials: R
authors.lastname: Gispert
authors.forename: Josep M
authors.initials: JM
authors.lastname: Borràs
authors.forename: Josepa
authors.initials: J
authors.lastname: Ribes
mesh_terms: D003627:Data Interpretation, Statistical; D003710:Demography; D004812:Epidemiologic Methods; D006801:Humans; D015994:Incidence; D020407:Internet; D009026:Mortality; D009369:Neoplasms / Q000401:mortality; D012306:Risk; D013030:Spain / Q000453:epidemiology