title: Surveyance of disease frequency in a population by linkage to diagnostic laboratory databases. A system for monitoring the incidences of hyper- and hypothyroidism as part of the Danish iodine supplementation program.
abstract: In Denmark an increase in iodine intake through salt iodization has been introduced in 1998. In parallel a program for surveyance of thyroid diseases in the population was developed as recommended by UNICEF and WHO.
  
  
  OBJECTIVE
  To develop and evaluate a computer based system to identify and register new cases of hyper- and hypothyroidism in a well defined cohort, by linkage to diagnostic laboratory databases.
  
  
  RESULTS
  (1) Two sub cohorts for monitoring were defined (n=535,859), and evaluated to minimize loss of new cases. Collaboration was established with laboratories covering thyroid hormone analyses in the cohort; (2) a diagnostic algorithm was defined and evaluated against clinical practice; (3) evaluation of the laboratory methods employed by the four participating laboratories, to ensure they would reach the same diagnosis in a patient; (4) a register database was developed which used data imported from the laboratory databases to automatically identify previously unknown cases of hyper- and hypothyroidism and record diagnostic activity in the area. All parts of the registration were carefully evaluated.
  
  
  CONCLUSIONS
  We describe for the first time a computer based system for prospective measuring the incidence rate of hyper- and hypothyroidism. The system is particularly useful for monitoring of iodine supplementation programmes.
authors.affiliation: Department of Endocrinology and Medicine, Aalborg Hospital, Reberbansgade, DK-9000 Aalborg, Denmark. ibulow@aas.nja.dk
authors.forename: Inge Bülow
authors.initials: IB
authors.lastname: Pedersen
authors.forename: Peter
authors.initials: P
authors.lastname: Laurberg
authors.forename: Terkel
authors.initials: T
authors.lastname: Arnfred
authors.forename: Nils
authors.initials: N
authors.lastname: Knudsen
authors.forename: Torben
authors.initials: T
authors.lastname: Jørgensen
authors.forename: Hans
authors.initials: H
authors.lastname: Perrild
authors.forename: Lars
authors.initials: L
authors.lastname: Ovesen
mesh_terms: D016208:Databases, Factual; D003718:Denmark / Q000453:epidemiology; D019587:Dietary Supplements; D006801:Humans; D006980:Hyperthyroidism / Q000453:epidemiology*; D007037:Hypothyroidism / Q000453:epidemiology*; D015994:Incidence; D007455:Iodine; D007753:Laboratories; D009313:National Health Programs; D011159:Population Surveillance / Q000379:methods*; D011446:Prospective Studies
chemical_list: D007455:Iodine