title: On diagnosing rare disorders rarely: appropriate use of screening instruments.
abstract: The main aim of this study was to determine whether child mental health professionals who regularly use questionnaires to screen for mental disorders know that these questionnaires have a low predictive value when the base rate of a disorder is low. The study was based on a representative sample of professionals who used questionnaires regularly to screen for mental disorders. They were set a problem in which a clinic sample was screened with a questionnaire that, at a certain cut-point, had 80 % sensitivity and 80 % specificity, and in which the true base rate of disorder was 10%. Only 10% (5/48) of respondents answered correctly that just 30 % of individuals who scored above this cut-point would actually have the disorder and more than half of respondents believed that 80 % would have the disorder. Both users and designers of questionnaires need to be more aware of and explicit about their drawbacks as screens for mental disorders.
authors: Royal Manchester Children's Hospital, Pendlebury, UK.
authors: A
authors: A
authors: Clark
authors: R
authors: R
authors: Harrington
mesh_terms: D002648:Child; D002662:Child Health Services / Q000592:standards*; D002665:Child Psychiatry / Q000592:standards; D004739:England; D019538:Health Care Surveys; D006801:Humans; D015994:Incidence; D001523:Mental Disorders / Q000175:diagnosis* / Q000453:epidemiology; D008605:Mental Health Services / Q000592:standards*; D011364:Professional Practice / Q000592:standards / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales / Q000592:standards / Q000706:statistics & numerical data*; D012016:Reference Values; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards / Q000706:statistics & numerical data*