title: Design of stepwise screening for prediabetes and type 2 diabetes based on costs and cases detected.
abstract: OBJECTIVE
  To provide insight into the trade-off between cost per case detected (CPCD) and the detection rate in questionnaire-based stepwise screening for impaired fasting glucose and undiagnosed type 2 diabetes.
  
  
  METHODS
  We considered a stepwise screening in which individuals whose risk score exceeds a predetermined cutoff value are invited for further blood glucose testing. Using individual patient data to determine questionnaire sensitivity and specificity and external sources to determine screening costs and patient response rates, we rolled back a decision tree to estimate the CPCD and the detection rate for all possible cutoffs on the questionnaire.
  
  
  RESULTS
  We found a U-shaped relation between CPCD and detection rate, with high costs per case detected at very low and very high detection rates. Changes in patient response rates had a large impact on both the detection rate and the CPCD, whereas screening costs and questionnaire accuracy mainly impacted the CPCD.
  
  
  CONCLUSIONS
  Our applied method makes it possible to identify a range of efficient cutoffs where higher detection rates can be achieved at an additional cost per detected patient. This enables decision makers to choose an optimal cutoff based on their willingness to pay for additional detected patients.
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30.001 9700 RB, Groningen, The Netherlands. Electronic address: gimon.degraaf@gmail.com.
authors.forename: Gimon
authors.initials: G
authors.lastname: de Graaf
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30.001 9700 RB, Groningen, The Netherlands.
authors.forename: Douwe
authors.initials: D
authors.lastname: Postmus
authors.affiliation: Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30.001 9700 RB, Groningen, The Netherlands.
authors.forename: Stephan J L
authors.initials: SJ
authors.lastname: Bakker
authors.affiliation: Department of Epidemiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 30.001 9700 RB, Groningen, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Buskens
mesh_terms: D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011236:Prediabetic State / Q000175:diagnosis* / Q000453:epidemiology; D011322:Primary Prevention; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
keywords: Decision analysis; Diabetes mellitus; Health services research; Prediabetic state; Primary prevention; Screening; Technology assessment; Type 2