title: A study of diagnostic accuracy of the Florida Obsessive-Compulsive Inventory--Thai Version (FOCI-T).
abstract: BACKGROUND
  The Florida Obsessive-Compulsive Inventory (FOCI) is a self-reported measure to assess the symptoms and severity of obsessive-compulsive disorder (OCD), which can be completed in five minutes. Although preliminary studies have shown its good psychometric properties, the study of receiver operating characteristics (ROC) to use it as a screening tool has never been reported elsewhere. This study aimed to use the ROC analysis to determine the optimal cut-off score of the Thai version of the FOCI (FOCI-T).
  
  
  METHODS
  A total of 197 participants completed the FOCI-T, the Patient Health Questionnaire (PHQ-9), and the Pictorial Thai Quality of Life (PTQL), and they were also interviewed with the Mini International Neuropsychiatric Interview (MINI) for their diagnosis. The ROC analyses of the FOCI-T Severity Scores were computed to determine the best cut-off score.
  
  
  RESULTS
  When the Thai version of the MINI was used in the interview, it was found that 38 participants were diagnosed with OCD, 43 participants were non-OCD, and 116 participants were healthy adults. The ROC analyses indicated that the FOCI-T Severity Scale could significantly distinguish OCD patients from non-OCD patients and healthy adults. The area under curve was estimated to be 0.945 (95%CI = 0.903-0.972). A cut-off score of ≥ 5 provided the best sensitivity (0.92) and specificity (0.82).
  
  
  CONCLUSIONS
  The Thai version of the Florida Obsessive-Compulsive Inventory has demonstrated its good predictive abilities, so it could be used as a brief screening tool to detect obsessive-compulsive disorder patients with high sensitivity and specificity.
authors.affiliation: Department of Psychiatry, Ramathibodi Hospital; Faculty of Medicine, Mahidol University, Mahidol, Thailand. ratana.sai@mahidol.ac.th.
authors.forename: Ratana
authors.initials: R
authors.lastname: Saipanish
authors.affiliation: Department of Psychiatry, Ramathibodi Hospital; Faculty of Medicine, Mahidol University, Mahidol, Thailand. thanita.hin@mahidol.edu.
authors.forename: Thanita
authors.initials: T
authors.lastname: Hiranyatheb
authors.affiliation: Department of Psychiatry, Ramathibodi Hospital; Faculty of Medicine, Mahidol University, Mahidol, Thailand. porpsy@gmail.com.
authors.forename: Sudawan
authors.initials: S
authors.lastname: Jullagate
authors.affiliation: Department of Psychiatry, Ramathibodi Hospital; Faculty of Medicine, Mahidol University, Mahidol, Thailand. drmanote@gmail.com.
authors.forename: Manote
authors.initials: M
authors.lastname: Lotrakul
mesh_terms: D000328:Adult; D044466:Asian People; D005260:Female; D005431:Florida; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis*; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics; D011788:Quality of Life; D012372:ROC Curve; D055815:Young Adult