title: Should psychological distress screening in the community account for self-perceived health status?
abstract: OBJECTIVE
  Psychological distress questionnaires are often used as screening instruments for mental disorders in clinical and epidemiologic settings. Poor physical health may affect the screening properties of a questionnaire. We evaluate the effect of self-perceived health status on the screening performance of the Kessler K10 and K6 scales in a community sample.
  
  
  METHODS
  We used data from the Canadian Community Health Survey: Mental Health and Well-Being (CCHS 1.2). Psychological distress was measured by the 6-item (K6) and the 10-item (K10) Kessler instrument. Depression and anxiety disorders were assessed using the World Mental Health Composite International Diagnostic Interview (1-month estimates). Optimal cut-off points regarding health status were determined by finding the K6 and K10 values that allowed for the best balance between sensitivity and specificity. Stratum-specific likelihood ratios (SSLRs) were computed to define strata with discriminating power.
  
  
  RESULTS
  There was a strong association between the screening performance of the K6 and K10 scales and self-perceived health status: for the K10 scale, a cut-off point of 5/6 yielded the best balance between sensitivity and specificity for subjects with excellent or very good health status, while a cut-off point of 14/15 yielded the best balance between sensitivity and specificity for subjects with poor health status.
  
  
  CONCLUSIONS
  The combination of the K6 and K10 scales, with a self-rated health status item, may improve screening properties of the 2 scales.
authors.affiliation: Department of Psychiatry, McGill University, Douglas Hospital Research Centre, Montreal, Quebec. norbert.schmitz@douglas.mcgill.ca
authors.forename: Norbert
authors.initials: N
authors.lastname: Schmitz
authors.forename: Alain
authors.initials: A
authors.lastname: Lesage
authors.forename: Jianli
authors.initials: J
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000379:Agoraphobia / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D001294:Attitude to Health; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D002170:Canada; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D015577:Geriatric Assessment; D006304:Health Status; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D008875:Middle Aged; D016584:Panic Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult