title: The Patient Health Questionnaire 12 Somatic Symptom scale as a predictor of symptom severity and consulting behaviour in patients with irritable bowel syndrome and symptomatic diverticular disease.
abstract: BACKGROUND
  Anxiety, depression and nongastrointestinal symptoms are often prominent in irritable bowel syndrome (IBS), but their relative value in patient management has not been quantitatively assessed. We modified the Patient Health Questionnaire 15 (PHQ-15) by excluding three gastrointestinal items to create the PHQ-12 Somatic Symptom (PHQ-12 SS) scale.
  
  
  OBJECTIVE
  To compare the value of the PHQ-12 SS scale with the Hospital Anxiety and Depression (HAD) scale in predicting symptoms and patient behaviour in IBS and diverticular disease.
  
  
  METHODS
  We compared 151 healthy volunteers (HV), 319 IBS patients and 296 patients with diverticular disease (DD), 113 asymptomatic [ASYMPDD] and 173 symptomatic DD (SYMPDD).
  
  
  RESULTS
  Patient Health Questionnaire 12 SS scores for IBS and SYMPDD were significantly higher than HV. Receiver-operator curves showed a PHQ-12 SS >6, gave a sensitivity for IBS of 66.4% with a specificity of 94.7% and a positive likelihood ratio (PLR) = 13.2, significantly better than that associated with an HAD anxiety score >7, PLR = 3.0 and depression score >7 PLR = 6.5. PHQ-12 SS correlated strongly with IBS severity scale and GP visits in both IBS and DD.
  
  
  CONCLUSIONS
  The PHQ-12 SS scale is a useful clinical tool which correlates with patient behaviour in both IBS and symptomatic DD.
authors.affiliation: Nottingham Digestive Diseases Centre, University Hospital, UK. robin.spiller@nottingham.ac.uk
authors.forename: R C
authors.initials: RC
authors.lastname: Spiller
authors.forename: D J
authors.initials: DJ
authors.lastname: Humes
authors.forename: E
authors.initials: E
authors.lastname: Campbell
authors.forename: M
authors.initials: M
authors.lastname: Hastings
authors.forename: K R
authors.initials: KR
authors.lastname: Neal
authors.forename: G E
authors.initials: GE
authors.lastname: Dukes
authors.forename: P J
authors.initials: PJ
authors.lastname: Whorwell
mesh_terms: D000328:Adult; D000368:Aged; D001007:Anxiety / Q000209:etiology* / Q000523:psychology; D003863:Depression / Q000209:etiology* / Q000523:psychology; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012017:Referral and Consultation; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires