title: Validation of patient health questionnaire (PHQ) for major depression in Chinese outpatients with multiple somatic symptoms: a multicenter cross-sectional study.
abstract: BACKGROUND
  Despite the high co-morbidity of depressive symptoms in patients with multiple somatic symptoms, the validity of the 9-item Patient Health Questionnaire (PHQ-9) has not yet been investigated in Chinese patients with multiple somatic symptoms.
  
  
  METHODS
  The multicenter cross-sectional study was conducted in ten outpatient departments located in four cities in China. The psychometric properties of the PHQ-9 were examined by confirmative factor analysis (CFA). Criterion validation was undertaken by comparing results with depression diagnoses obtained from the Mini International Neuropsychiatric Interview (MINI) as the gold standard.
  
  
  RESULTS
  Overall, 491 patients were recruited of whom 237 had multiple somatic symptoms (SOM+ group, PHQ-15≥10). Cronbach׳s α of the PHQ-9 was 0.87, 0.87, and 0.90 for SOM+ patients, SOM- patients, and total sample respectively. All items and the total score were moderately correlated. The factor models of PHQ-9 tested by CFA yielded similar diagnostic performance when compared to sum score estimation. Multi-group confirmatory factor analysis based on unidimensional model showed similar psychometric properties over the groups with low and high somatic symptom burden. The optimal cut-off point to detect depression in Chinese outpatients was 10 for PHQ-9 (sensitivity=0.77, specificity=0.76) and 3 for PHQ-2 (sensitivity=0.77, specificity=0.74).
  
  
  CONCLUSIONS
  Potential selection bias and nonresponse bias with applied sampling method.
  
  
  CONCLUSIONS
  PHQ-9 (cut-off point=10) and PHQ-2 (cut-off point=3) were reliable and valid to detect major depression in Chinese patients with multiple somatic symptoms.
authors.affiliation: Department of Psychological Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Shuaifuyuan 1, Dongcheng District, Beijing 100730, PR China.
authors.forename: Nana
authors.initials: N
authors.lastname: Xiong
authors.affiliation: Department of Psychosomatic Medicine and Psychotherapy, University Medical Centre Freiburg, Freiburg, Germany.
authors.forename: Kurt
authors.initials: K
authors.lastname: Fritzsche
authors.affiliation: Department of Psychological Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Shuaifuyuan 1, Dongcheng District, Beijing 100730, PR China. Electronic address: weijing@pumch.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Psychological Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Shuaifuyuan 1, Dongcheng District, Beijing 100730, PR China.
authors.forename: Xia
authors.initials: X
authors.lastname: Hong
authors.affiliation: Institute of Psychology, University of Freiburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Leonhart
authors.affiliation: Department of Psychosomatic Medicine, Dongfang Hospital, School of Medicine, Tongji University, Shanghai, PR China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Mental Health Centre, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Tian
authors.affiliation: Medical Clinic for Internal Medicine, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany; Population Health Strategic Research Centre, School of Health and Social Development, Deakin University, Burwood, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Nolte
authors.affiliation: Medical Clinic for Internal Medicine, Department of Psychosomatic Medicine, Charité - Universitätsmedizin Berlin, Germany; Institute for Social Medicine, Epidemiology and Health Economics, Charité - Universitätsmedizin Berlin, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Fischer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis* / Q000523:psychology; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000523:psychology; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D010045:Outpatients / Q000706:statistics & numerical data; D011594:Psychometrics; D012372:ROC Curve; D015203:Reproducibility of Results; D015983:Selection Bias; D012680:Sensitivity and Specificity; D013001:Somatoform Disorders / Q000523:psychology*; D011795:Surveys and Questionnaires / Q000592:standards
keywords: Chinese; Confirmative factor analysis; Depression; Multiple somatic symptoms; Patient Health Questionnaire-9; Somatic symptom disorder