title: Psychological factors influence the overlap syndrome in functional gastrointestinal disorders and their effect on quality of life among firefighters in South Korea.
abstract: OBJECTIVE
  The aim of this study was to investigate the predictor variables that could influence overlap syndrome in functional gastrointestinal disorders (FGID) among firefighters in Korea.
  
  
  METHODS
  Data collected from 1217 firefighters in Korea were reviewed. FGID were diagnosed according to the Rome III diagnostic criteria. Psychological factors were measured by self-reported questionnaires. The scores for depression, anxiety, quality of life (QOL) and occupational job stress were analyzed. The correlation between psychological factors and QOL was analyzed and a stepwise multiple regression analysis was performed.
  
  
  RESULTS
  FGID were observed in 461 (37.9%) participants. In those with FGID, functional heartburn (FH) was most common (32.2%), followed by functional dyspepsia (12.2%). Patients with overlap syndrome had the highest depression, anxiety and occupational stress score than those having non-overlap syndrome and healthy controls, respectively (depression: F = 142.29, η(2)  = 0.190; anxiety: F = 88.33, η(2)  = 0.127; occupational stress: F = 43.68, η(2)  = 0.067; all P < 0.001). Healthy controls had the highest QOL score (F = 73.39, P < 0.001, η(2)  = 0.108). Pychological factors were significantly correlated with QOL in the overlap syndrome of FGID. After the stepwise selection, the final model explained 45.6% of predictable variance and contained four significant variables: depression, self-esteem, occupational stress and anxiety.
  
  
  CONCLUSIONS
  Psychological factors are associated with the overlap syndrome of FGID. Acknowledging this common comorbidity may facilitate the recognition and treatment of patients with FGID.
authors.affiliation: Department of Psychiatry, School of Medicine, Wonkwang University, Iksan, Korea.
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Jang
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Korea.
authors.forename: Han-Seung
authors.initials: HS
authors.lastname: Ryu
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, School of Medicine, Wonkwang University, Iksan, Korea.
authors.forename: Suck-Chei
authors.initials: SC
authors.lastname: Choi
authors.affiliation: Department of Psychiatry, School of Medicine, Wonkwang University, Iksan, Korea.
authors.forename: Sang-Yeol
authors.initials: SY
authors.lastname: Lee
mesh_terms: D000328:Adult; D001007:Anxiety / Q000175:diagnosis; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis; D005260:Female; D061388:Firefighters / Q000523:psychology*; D005767:Gastrointestinal Diseases / Q000175:diagnosis / Q000523:psychology*; D006356:Heartburn / Q000175:diagnosis / Q000523:psychology; D006801:Humans; D008297:Male; D054527:Mass Casualty Incidents / Q000523:psychology; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis / Q000523:psychology*; D011788:Quality of Life; D012044:Regression Analysis; D056910:Republic of Korea; D057566:Self Report; D013315:Stress, Psychological / Q000175:diagnosis / Q000523:psychology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: anxiety; depression; functional gastrointestinal disorders; occupational job stress; overlap syndrome; quality of life