title: Randomized response estimates for doping and illicit drug use in elite athletes.
abstract: BACKGROUND
  To date, there are estimates for the percentage of unknown cases of doping and illicit drug use in fitness sports, but not for elite sports. This can be attributed to the problem of implementing questionnaires and surveys to get reliable epidemiological estimates of deviant or illicit behaviour.
  
  
  METHODS
  All athletes questioned were subject to doping controls as members or junior members of the national teams. In order to estimate the prevalence of doping and illicit drug abuse, the athletes were either issued an anonymous standardized questionnaire (SQ; n=1394) or were interviewed using randomized response technique (RRT; n=480). We used a two-sided z-test to compare the SQ and RRT results with the respective official German NADA data on the prevalence of doping.
  
  
  RESULTS
  Official doping tests only reveal 0.81% (n=25,437; 95% CI: 0.70-0.92%) of positive test results, while according to RRT 6.8% (n=480; 95% CI: 2.7-10.9%) of our athletes confessed to having practiced doping (z=2.91, p=0.004). SQ and RRT both revealed a prevalence of about 7% for illicit drug use, but SQ failed to indicate a realistic prevalence of doping (0.20%; 95% CI: 0.02-0.74%).
  
  
  CONCLUSIONS
  We demonstrate for the first time that data from official doping tests underestimate the true prevalence of doping in elite sports by more than a factor of eight. Our results indicate that implementing RRT before and after anti-doping measures could be a promising method for evaluating the effectiveness of anti-doping programs.
authors.affiliation: Medical Clinic, Department of Sports Medicine, University of Tübingen, Silcherstrasse 5, Tübingen, Germany. heiko.striegel@med.uni-tuebingen.de
authors.forename: Heiko
authors.initials: H
authors.lastname: Striegel
authors.forename: Rolf
authors.initials: R
authors.lastname: Ulrich
authors.forename: Perikles
authors.initials: P
authors.lastname: Simon
mesh_terms: D000293:Adolescent; D004300:Doping in Sports / Q000706:statistics & numerical data*; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D015995:Prevalence; D019966:Substance-Related Disorders / Q000453:epidemiology*; D011795:Surveys and Questionnaires