The Reliability,Validity And Cut-off Point Of The Chinese Version Of Florida Obsessive-compulsive Inventory

Background: Obsessive-Compulsive Disorder is a common mental disorder with which the patients always have obsessive thoughts and compulsive behaviors as the main clinical manifestation.OCD patients suffer from instructive thoughts,images and impulse which makes them feel so anxiety and painful,that they usually make repetitive actions or mental activity to relieve the pain over and over again.So the assessment tools of OCD are more and more important for clinical work and research,the Florida Obsessive-Compulsive Inventory can detect whether OCD symptoms exist and the severity of OCD in the same time.It is a self report inventory which developed from Yale-Brown Obsessive-Compulsive Scale that is the "gold standard" in the assessment tools of OCD symptoms.This study tries to discuss the reliability and validity of the Chinese version of the FOCI in clinical sample and to determine the cut-off point with the results of the study.Methods: One psychotherapist from Shanghai Mental Health Center translate FOCI to Chinese Version,then it was translated back by another psychotherapist,both of them passed the CET-6,the translation and back-translation were confirmed by the team of Professor Goodman and Professor Storch,then the FOCI was assessed by 20 OCD patients and 20 healthy people respectively,according to the feedback,the translator discussed with Storch and modified the 13 rd and 19 th items.153 OCD patients,150 patients in case-control group and 150 healthy people participated in this study.The case-control group consist of the patients who were diagnosed as Anxiety disorder,Depression disorder.150 healthy controls participated in this study.All the three groups completed general situation Questionnaires,including Yale-Brown Obsessive-Compulsive Scale(YBOCS),Florida Obsessive-Compulsive Inventory(FOCI),Obsessive-Compulsive Inventory-revised(OCI-R),the second edition of Beck Depression Inventory(BDI-?),Beck Anxiety Inventory(BAI),the Mos 36-item short-form health survey(SF-36).Among the OCD patients,47 participants were re-tested in two weeks interval.The study used the receiver operating characteristic curve(ROC curve)to choose the cut-off point of the Chinese version of FOCI.Results: The internal consistency reliability of the FOCI in the OCD group is as below-the K-R20 value of symptom checklist is 0.813,and its Cronabach's alpha coefficient of the severity scale is 0.840.Its retest reliability of symptom checklist and severity scale is 0.934 and 0.935 respectively.Both of the translation and back translation of Chinese version of FOCI have been confirmed by Goodman's team,and it was tested in the Chinese population so that the Chinese version of FOCI has good content validity.The correlation between the symptom checklist of FOCI and the YBOCS-SC was 0.806,the correlation between the symptom checklist of FOCI and OCI-R was 0.713.The correlation between the severity scale of the FOCI and Y-BOCS was 0.840.The correlation between the severity scale of FOCI and OCI-R was 0.450.The correlation between the FOCI symptom checklist and BDI-?,BAI,SF-36 is poor to moderate,the correlation between FOCI severity scale and BDI-?,BAI,SF-36 were moderate,indicating that the discriminant validity of FOCI was acceptable.The differences among the OCD patients,case-controls and healthy controls were significant(p?0.01).Both of the significant differences of symptom checklist and severity scale shows that the scores of the patients from OCD group were significantly higher than those from case-control group which were higher than those from healthy group(p?0.01).The results of the ROC curve analysis showed that the area under the curve(AUC)of symptom checklist was 0.766(95% CI: 0.724 0.809,p?0.01).The AUC of severity scale of FOCI was 0.914(95% CI: 0.88 0.940,p?0.01),and the Youden index was 0.723,the sensitivity was 87.6% and the specificity was 84.6%,its cut-off point was 8.Conclusions: The Chinese version of FOCI has good internal consistency and retest reliability,content validity,convergent validity,factor validity and discriminate validity,empirical validity in Chinese clinical sample.It was able to distinguish OCD patients,case-controls and healthy controls,the ROC curve analysis shows strong diagnostic performance of FOCI severity scale,and its cut-off point was 8.