title: Regional variation in the modeling of donation frequency: the case of Héma-Québec, Canada.
abstract: BACKGROUND
  Many studies on factors that can affect the frequency of blood donation have shown the influence of several individual characteristics. However, few studies have analyzed regional variations in blood donation frequency. The objective of this article is to verify to what extent individual and geographic variables influence blood donation in the Province of Québec, Canada.
  
  
  METHODS
  This article used a database provided by Héma-Québec (the organization in charge of blood collection in Québec), which included 426,247 donors, who made 1.4 million donations over a period of 5 years. Using the donors' residential postal codes and those of the blood collection sites, we created two geographic variables: the distance between the donor's place of residence and his or her collection site and each donor's region of residence. We subsequently modeled the frequency of blood donation and the different donor categories (based on the number of blood donations) using both a negative binomial regression model and an ordinal logistic regression model.
  
  
  RESULTS
  The results indicate that, once the individual characteristics have been taken into account, the geographic variables, including proximity to the collection site, have a significant impact on the frequency of blood donation. Likewise, according to the results of the negative binomial model, among the 17 regions in the Province of Québec, there are five regions where blood donation incidence rate ratios (IRRs) are very high, that is, Abitibi-Témiscamingue (IRR, 1.77; 95% confidence interval [CI], 1.61-1.95); Bas-Saint-Laurent (IRR, 1.75; 95% CI, 1.59-1.93); Saguenay-Lac-Saint-Jean (IRR, 1.68; 95% CI, 1.53-1.84); Centre-du-Québec (IRR, 1.66; 95% CI, 1.51-1.83); and Chaudière-Appalaches (IRR, 1.62; 95% CI, 1.48-1.78).
  
  
  CONCLUSIONS
  Such knowledge of the geography of blood donations makes it possible to better target certain regions when planning new blood drives, to ensure a constant blood supply.
authors.affiliation: Centre Urbanisation Culture Société, Institut National de la Recherche Scientifique, Montréal, Québec, Canada.
authors.forename: Marie-Soleil
authors.initials: MS
authors.lastname: Cloutier
authors.forename: Philippe
authors.initials: P
authors.lastname: Apparicio
authors.forename: Jean
authors.initials: J
authors.lastname: Dubé
authors.forename: Johanne
authors.initials: J
authors.lastname: Charbonneau
authors.forename: Gilles
authors.initials: G
authors.lastname: Delage
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001771:Blood Banks / Q000706:statistics & numerical data*; D001782:Blood Donors / Q000706:statistics & numerical data*; D016208:Databases, Factual / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011792:Quebec / Q000453:epidemiology; D017678:Sex Distribution; D019371:Topography, Medical / Q000706:statistics & numerical data; D055815:Young Adult