title: Incidence of childhood-onset type 1 diabetes in Biscay, Spain, 1990-2013.
abstract: To identify the incidence rate (IR) and epidemiologic trends of childhood type 1 diabetes mellitus (T1DM) in children aged 0 to 14-yr-old from 1990 to 2013, in the north of Spain (Biscay).
  
  
  
  A prospective-retrospective study was performed. Capture-recapture method was used: primary cases were ascertained from hospital register and a secondary independent data source was obtained from diabetes associations and public health plan database. Age and sex-standardized incidence rates were calculated using direct method, assuming an equal distribution in each age/sex group. In order to identify and analyse trends the period studied was divided into two (1990-2001 and 2002-2013) 11-year periods. The 95% confidence interval (CI) was estimated assuming the Poisson distribution.
  
  
  
  A total of 399 new cases were identified throughout the study. Mean age at diagnosis was 8.9 ± 3.7 yr. Completeness of ascertainment was 99.1%. Mean annual age-standardized IR was 10.7 (95% CI: 9.6-11.7). The mean incidence for the 0-4, 5-9 and 10-14 age groups was 5.1, 14.6 and 13.2 per 100,000 children/yr, respectively. The incidence rate trend in the whole group was not statistically significant. In the 10-14 age group we found a yearly average increase (2.5% [CI 95% 0.4-4.6]; P < 0.05) and analysing by sex, this statistically significant incidence trend was observed only in boys. We did not find a seasonal onset pattern.
  
  
  
  The IR did not increase in this population during the period studied unlike the results in other Spanish regions and European Countries.
authors.affiliation: Paediatric Endocrinology Unit, Basurto University Hospital, Bilbao, Spain.|BioCruces Health Research Institute.|University of the Basque Country (EHU/UPV).
authors.forename: Concepción
authors.initials: C
authors.lastname: Fernández-Ramos
authors.affiliation: Clinical Epidemiology Unit, Cruces University Hospital, Baracaldo, Spain.|BioCruces Health Research Institute.
authors.forename: Eunate
authors.initials: E
authors.lastname: Arana-Arri
authors.affiliation: Paediatric Endocrinology Unit, Cruces University Hospital, Baracaldo, Spain.|BioCruces Health Research Institute.
authors.forename: Paloma
authors.initials: P
authors.lastname: Jiménez-Huertas
authors.affiliation: Paediatric Endocrinology Unit, Cruces University Hospital, Baracaldo, Spain.|BioCruces Health Research Institute.|University of the Basque Country (EHU/UPV).|CIBERDEM.
authors.forename: Amaia
authors.initials: A
authors.lastname: Vela
authors.affiliation: Paediatric Endocrinology Unit, Cruces University Hospital, Baracaldo, Spain.|BioCruces Health Research Institute.|CIBERDEM.
authors.forename: Itxaso
authors.initials: I
authors.lastname: Rica
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies; D013030:Spain / Q000453:epidemiology
keywords: Spain; epidemiology; incidence; incidence trend; type 1 diabetes mellitus