title: Estimation of disease incidence in claims data dependent on the length of follow-up: a methodological approach.
abstract: OBJECTIVE
  To analyze the impact of the length of disease-free intervals on incidence estimation.
  
  
  METHODS
  Statutory health insurance sample in Germany.
  
  
  METHODS
  Overestimation of the incidence in the first quarter of 2008 for three selected diseases, diabetes mellitus, colorectal cancer, and heart failure, depending on different lengths of preceding disease-free intervals.
  
  
  METHODS
  Continuously insured from 2000 until 2008 ≥ 18 years (N = 144,907).
  
  
  RESULTS
  Compared with an 8-year disease-free period, incidence overestimations for diabetes, colorectal cancer, and heart failure were 40, 23, and 43 percent defining a 1-year, and 5, 9, and 5 percent defining a 5-year disease-free period, respectively.
  
  
  CONCLUSIONS
  Depending on the specific disease, caution has to be taken while using short disease-free periods because incidence estimates may be extremely overestimated.
authors.affiliation: PMV Research Group at the Department of Child and Adolescent Psychiatry and Psychotherapy, University of Cologne, Herderstr. 52, 50931 Cologne, Germany. Sascha.Abbas@uk-koeln.de
authors.forename: Sascha
authors.initials: S
authors.lastname: Abbas
authors.forename: Peter
authors.initials: P
authors.lastname: Ihle
authors.forename: Ingrid
authors.initials: I
authors.lastname: Köster
authors.forename: Ingrid
authors.initials: I
authors.lastname: Schubert
mesh_terms: D015179:Colorectal Neoplasms / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007344:Insurance Claim Reporting / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic; D013997:Time Factors