title: The methodological quality of three foundational law enforcement Drug Influence Evaluation validation studies.
abstract: BACKGROUND
  A Drug Influence Evaluation (DIE) is a formal assessment of an impaired driving suspect, performed by a trained law enforcement officer who uses circumstantial facts, questioning, searching, and a physical exam to form an unstandardized opinion as to whether a suspect's driving was impaired by drugs. This paper first identifies the scientific studies commonly cited in American criminal trials as evidence of DIE accuracy, and second, uses the QUADAS tool to investigate whether the methodologies used by these studies allow them to correctly quantify the diagnostic accuracy of the DIEs currently administered by US law enforcement.
  
  
  RESULTS
  Three studies were selected for analysis. For each study, the QUADAS tool identified biases that distorted reported accuracies. The studies were subject to spectrum bias, selection bias, misclassification bias, verification bias, differential verification bias, incorporation bias, and review bias. The studies quantified DIE performance with prevalence-dependent accuracy statistics that are internally but not externally valid.
  
  
  CONCLUSIONS
  The accuracies reported by these studies do not quantify the accuracy of the DIE process now used by US law enforcement. These studies do not validate current DIE practice.
authors.affiliation: 10785 East Crestline Place, Englewood CO 80111, USA. GregKaneMD@hotmail.com.
authors.forename: Greg
authors.initials: G
authors.lastname: Kane
mesh_terms: D015982:Bias; D003955:Diagnostic Tests, Routine / Q000592:standards; D018450:Disease Progression; D006801:Humans; D035846:Law Enforcement / Q000379:methods*; D004364:Pharmaceutical Preparations / Q000032:analysis*; D011785:Quality Assurance, Health Care; D012015:Reference Standards; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
chemical_list: D004364:Pharmaceutical Preparations