title: Validity of the Patient Health Questionnaire (PHQ)-9 and PHQ-2 in general internal medicine primary care at a Japanese rural hospital: a cross-sectional study.
abstract: OBJECTIVE
  Two depression screening tools, Patient Health Questionnaire (PHQ)-9 and PHQ-2, have not had their validity examined in general internal medicine settings in Japan. We examined the validity of these screening tools.
  
  
  METHODS
  A total of 598 outpatients of an internal medicine clinic in a rural general hospital were enrolled consecutively and stratified by PHQ-9 score. Seventy-five patients randomly selected and 29 patients whose results from the PHQ-9 were considered to be positive for depressive disorder were then interviewed with a semistructured interview, the Mini International Neuropsychiatric Interview. We calculated diagnostic accuracy of the PHQ-9 and PHQ-2 to detect major depression and that of the suicidality item of the PHQ-9 to detect suicidality using sampling weights with multiple imputations.
  
  
  RESULTS
  Sensitivity and specificity for depression were 0.86 and 0.85, respectively, for the PHQ-9 with cutoff points of 4/5, and 0.77 and 0.95, respectively, for the PHQ-2 with cutoff points of 2/3. Sensitivity and specificity of the suicidality item of the PHQ-9 were 0.70 and 0.97, respectively.
  
  
  CONCLUSIONS
  In internal medicine clinics in Japanese rural hospitals, the PHQ-2 with an optimal cutoff point for each setting plus the suicidality item of the PHQ-9 can be recommended to detect depression without missing suicidality.
authors.affiliation: Department of Neuropsychiatry, Okayama University Hospital, Okayama, Japan; Center for Suicide Prevention, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan. Electronic address: masatoshiinagaki@okayama-u.ac.jp.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Inagaki
authors.forename: Tsuyuka
authors.initials: T
authors.lastname: Ohtsuki
authors.forename: Naohiro
authors.initials: N
authors.lastname: Yonemoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kawashima
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Saitoh
authors.forename: Yuetsu
authors.initials: Y
authors.lastname: Oikawa
authors.forename: Mie
authors.initials: M
authors.lastname: Kurosawa
authors.forename: Kumiko
authors.initials: K
authors.lastname: Muramatsu
authors.forename: Toshi A
authors.initials: TA
authors.lastname: Furukawa
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Yamada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003866:Depressive Disorder / Q000175:diagnosis; D003865:Major Depressive Disorder / Q000175:diagnosis*; D005260:Female; D006780:Hospitals, Rural; D006801:Humans; D007388:Internal Medicine; D007564:Japan; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D011320:Primary Health Care; D011594:Psychometrics / Q000295:instrumentation; D015203:Reproducibility of Results; D012424:Rural Population; D012680:Sensitivity and Specificity; D059020:Suicidal Ideation; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Depression; Internal medicine; Patient Health Questionnaire; Primary care; Screening