title: Cancer incidence estimation at a district level without a national registry: a validation study for 24 cancer sites using French health insurance and registry data.
abstract: BACKGROUND
  District-level cancer incidence estimation is an important issue in countries without a national cancer registry. This study aims to both evaluate the validity of district-level estimations in France for 24 cancer sites, using health insurance data (ALD demands--Affection de Longue Durée) and to provide estimations when considered valid. Incidence is estimated at a district-level by applying the ratio between the number of first ALD demands and incident cases (ALD/I ratio), observed in those districts with cancer registries, to the number of first ALD demands available in all districts. These district-level estimations are valid if the ratio does not vary greatly across the districts or if variations remain moderate compared with variations in incidence rates.
  
  
  METHODS
  Validation was performed in the districts covered by cancer registries over the period 2000-2005. The district variability of the ALD/I ratio was studied, adjusted for age (mixed-effects Poisson model), and compared with the district variability in incidence rate. The epidemiological context is also considered in addition to statistical analyses.
  
  
  RESULTS
  District-level estimation using the ALD/I ratio was considered valid for eight cancer sites out of the 24 studied (lip-oral cavity-pharynx, oesophagus, stomach, colon-rectum, lung, breast, ovary and testis) and incidence maps were provided for these cancer sites.
  
  
  CONCLUSIONS
  Estimating cancer incidence at a sub-national level remains a difficult task without a national registry and there are few studies on this topic. Our validation approach may be applied in other countries, using health insurance or hospital discharge data as correlate of incidence.
authors.affiliation: Institut de veille sanitaire, Départements des maladies chroniques et des traumatismes, Saint-Maurice, France. z.uhry@invs.sante.fr
authors.forename: Zoé
authors.initials: Z
authors.lastname: Uhry
authors.forename: Laurent
authors.initials: L
authors.lastname: Remontet
authors.forename: Marc
authors.initials: M
authors.lastname: Colonna
authors.forename: Aurélien
authors.initials: A
authors.lastname: Belot
authors.forename: Pascale
authors.initials: P
authors.lastname: Grosclaude
authors.forename: Nicolas
authors.initials: N
authors.lastname: Mitton
authors.forename: Solenne
authors.initials: S
authors.lastname: Delacour-Billon
authors.forename: Julie
authors.initials: J
authors.lastname: Gentil
authors.forename: Marjorie
authors.initials: M
authors.lastname: Boussac-Zarebska
authors.forename: Nadine
authors.initials: N
authors.lastname: Bossard
authors.forename: Arlette
authors.initials: A
authors.lastname: Danzon
authors.forename: Michelle
authors.initials: M
authors.lastname: Altana
authors.forename: François
authors.initials: F
authors.lastname: Frete
authors.forename: Alain
authors.initials: A
authors.lastname: Weill
authors.forename: Agnès
authors.initials: A
authors.lastname: Rogel
mesh_terms: D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007348:Insurance, Health; D008297:Male; D008962:Models, Theoretical; D009369:Neoplasms / Q000453:epidemiology*; D012042:Registries