title: Comparison of surveillance-based metrics for the assessment and monitoring of disease detection: simulation study about type 2 diabetes.
abstract: Screening and detection of cases are a common public health priority for treatable chronic conditions with long subclinical periods. However, the validity of commonly-used metrics from surveillance systems for rates of detection (or case-finding) have not been evaluated.
  
  
  
  Using data from a Danish diabetes register and a recently developed illness-death model of chronic diseases with subclinical conditions, we simulate two scenarios of different performance of case-finding. We report different epidemiological indices to assess case-finding in both scenarios and compare the validity of the results.
  
  
  
  The commonly used ratio of detected cases over total cases may lead to misleading conclusions. Instead, the ratio of undetected cases over persons without a diagnosis is a more valid index to distinguish the quality of case-finding. However, incidence-based measures are preferable to prevalence based indicators.
  
  
  
  Prevalence-based indices for assessing case-finding should be interpreted with caution. If possible, incidence-based indices should be preferred.
authors.affiliation: German Diabetes Center, Leibniz Institute for Diabetes Research at the Heinrich-Heine-University Düsseldorf, Institute for Biometry and Epidemiology, Auf'm Hennekamp 65, Düsseldorf, 40225, Germany. Ralph.Brinks@ddz.uni-duesseldorf.de.|University Hospital at the Heinrich-Heine-University Düesseldorf, Hiller Research Unit for Rheumatology, Moorenstrasse 5, Düsseldorf, 40225, Germany. Ralph.Brinks@ddz.uni-duesseldorf.de.
authors.forename: Ralph
authors.initials: R
authors.lastname: Brinks
authors.affiliation: German Diabetes Center, Leibniz Institute for Diabetes Research at the Heinrich-Heine-University Düsseldorf, Institute for Biometry and Epidemiology, Auf'm Hennekamp 65, Düsseldorf, 40225, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Hoyer
authors.affiliation: Centers for Disease Control and Prevention, Division of Diabetes Translation, Atlanta, Georgia, USA.
authors.forename: Deborah B
authors.initials: DB
authors.lastname: Rolka
authors.affiliation: German Diabetes Center, Leibniz Institute for Diabetes Research at the Heinrich-Heine-University Düsseldorf, Institute for Biometry and Epidemiology, Auf'm Hennekamp 65, Düsseldorf, 40225, Germany.|German Center for Diabetes Research (DZD), Munich-Neuherberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Kuss
authors.affiliation: Centers for Disease Control and Prevention, Division of Diabetes Translation, Atlanta, Georgia, USA.
authors.forename: Edward W
authors.initials: EW
authors.lastname: Gregg
mesh_terms: D002908:Chronic Disease / Q000453:epidemiology*; D003718:Denmark / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*
keywords: Case-finding; Chronic disease; Compartment model; Diabetes; Incidence; Prevalence; Screening; Undiagnosed disease