title: Discriminant validity of the 12-item version of the general health questionnaire in a Swedish case-control study.
abstract: BACKGROUND
  The 12-item version of the General Health Questionnaire (GHQ-12) is widely used as a proxy for Affective Disorders in public health surveys, although the cut-off points for distress vary considerably between studies. The agreement between the GHQ-12 score and having a clinical disorder in the study population is usually unknown.
  
  
  OBJECTIVE
  This study aimed to assess the criterion validity and to determine the sensitivity and specificity of the GHQ-12 in the Swedish population.
  
  
  METHODS
  This study used 556 patient cases surveyed in specialized psychiatric care outpatient age- and sex-matched with 556 controls from the Stockholm Health Survey. Criterion validity for two scoring methods of GHQ-12 was tested using Receiver Operating Characteristics (ROC) analyses with Area Under the Curve (AUC) as a measure of agreement. Reference standard was (1) specialized psychiatric care and (2) current depression, anxiety or adjustment disorder.
  
  
  RESULTS
  Both the Likert and Standard GHQ-12 scoring method discriminated excellently between individuals using specialized psychiatric services and healthy controls (Likert index AUC = 0.86, GHQ index AUC = 0.83), and between individuals with current disorder from healthy controls (Likert index AUC = 0.90, GHQ index AUC = 0.88). The best cut-off point for the GHQ index was ≥4 (sensitivity = 81.7 and specificity = 85.4), and for the Likert index ≥14 (sensitivity = 85.5 and specificity = 83.2).
  
  
  CONCLUSIONS
  The GHQ-12 has excellent discriminant validity and is well suited as a non-specific measure of affective disorders in public mental health surveys.
authors: a Department of Public Health Sciences , Karolinska Institutet , Stockholm , Sweden.|b Centre for Epidemiology and Community Medicine, Stockholm County Council , Stockholm , Sweden.
authors: Andreas
authors: A
authors: Lundin
authors: a Department of Public Health Sciences , Karolinska Institutet , Stockholm , Sweden.
authors: Jill
authors: J
authors: Åhs
authors: b Centre for Epidemiology and Community Medicine, Stockholm County Council , Stockholm , Sweden.
authors: Nina
authors: N
authors: Åsbring
authors: a Department of Public Health Sciences , Karolinska Institutet , Stockholm , Sweden.|b Centre for Epidemiology and Community Medicine, Stockholm County Council , Stockholm , Sweden.
authors: Kyriaki
authors: K
authors: Kosidou
authors: a Department of Public Health Sciences , Karolinska Institutet , Stockholm , Sweden.|b Centre for Epidemiology and Community Medicine, Stockholm County Council , Stockholm , Sweden.
authors: Henrik
authors: H
authors: Dal
authors: c Department of Clinical Neuroscience , Karolinska Institutet , Stockholm , Sweden.|d Red Cross University Collage , Stockholm , Sweden.
authors: Petter
authors: P
authors: Tinghög
authors: c Department of Clinical Neuroscience , Karolinska Institutet , Stockholm , Sweden.|d Red Cross University Collage , Stockholm , Sweden.
authors: Fredrik
authors: F
authors: Saboonchi
authors: a Department of Public Health Sciences , Karolinska Institutet , Stockholm , Sweden.|b Centre for Epidemiology and Community Medicine, Stockholm County Council , Stockholm , Sweden.
authors: Christina
authors: C
authors: Dalman
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D059026:Diagnostic Self Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000175:diagnosis*; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*; D013548:Sweden; D055815:Young Adult
keywords: GHQ; Sensitivity and specificity; affective disorder; area under the curve; screening; self-assessment