title: Validity of the Greek version of the PHQ 15-item Somatic Symptom Severity Scale in patients with chronic medical conditions and correlations with emergency department use and illness perceptions.
abstract: BACKGROUND
  The PHQ-15 is a brief measure assessing the severity of somatic symptoms and is widely used in different health care settings. We aimed to assess the psychometric properties of its Greek version in patients with chronic physical illnesses seeking urgent or unscheduled care in the Accident and Emergency Department (AED).
  
  
  METHODS
  The PHQ-15 was translated into Greek using back-translation, and it was administered to 303 patients with diabetes, COPD and rheumatic diseases visiting our AED during a one-year period. Patients were interviewed with the MINI. Depressive (PHQ-9) and somatization symptoms (SCL-12), illness perceptions (B-IPQ) and health-related quality of life (WHOQOL-BREF) were also assessed to test criterion and concurrent validity.
  
  
  RESULTS
  The Greek version of the PHQ-15 showed acceptable internal consistency. Convergent validity was established by the strong associations observed between PHQ-15 scores and functional status, depressive symptom severity and AED visits during the previous year. PHQ-15 scores were also associated with the patients' concerns about personal and treatment illness's control and their beliefs regarding the number of bodily symptoms attributed to their illness (illness identity). The highly acceptable convergent and discriminant validity of the five individual bodily symptoms assessed by both the PHQ-15 and SCL-12 is a further construct validity indicator.
  
  
  CONCLUSIONS
  The present findings support the applicability of the Greek version of PHQ-15 in assessing common somatic symptoms either medically explained or unexplained in patients seeking care in the AED, further confirming that it can be considered suitable for use in a broad range of populations in clinical research.
authors.affiliation: University of Ioannina, Greece. Electronic address: tyfantis@cc.uoi.gr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hyphantis
authors.affiliation: Indiana University, USA.
authors.forename: Kurt
authors.initials: K
authors.lastname: Kroenke
authors.affiliation: University of Ioannina, Greece.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Papatheodorou
authors.affiliation: University of Ioannina, Greece.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Paika
authors.affiliation: University of Ioannina, Greece.
authors.forename: Nicholaos
authors.initials: N
authors.lastname: Theocharopoulos
authors.affiliation: University of Ioannina, Greece.
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Ninou
authors.affiliation: University of Manchester, UK.
authors.forename: Barbara
authors.initials: B
authors.lastname: Tomenson
authors.affiliation: University of Ceara, Fortaleza, Brazil.
authors.forename: Andre F
authors.initials: AF
authors.lastname: Carvalho
authors.affiliation: University of Manchester, UK.
authors.forename: Elspeth
authors.initials: E
authors.lastname: Guthrie
mesh_terms: D000368:Aged; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000523:psychology; D004636:Emergency Service, Hospital; D005260:Female; D006115:Greece; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics / Q000295:instrumentation*; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000523:psychology; D011788:Quality of Life; D015203:Reproducibility of Results; D012216:Rheumatic Diseases / Q000175:diagnosis* / Q000523:psychology; D012720:Severity of Illness Index; D013001:Somatoform Disorders / Q000175:diagnosis* / Q000523:psychology