title: Irritable bowel syndrome-specific health-related quality of life instrument: development and psychometric evaluation.
abstract: BACKGROUND
  Health-related quality of life (HRQOL) is an important outcome indicator for chronic disease, and particularly in the absence of biological markers for illness, such as with irritable bowel syndrome (IBS). The aims of this study were to develop and evaluate a new IBS-specific HRQOL instrument (IBS-HR-QOL).
  
  
  METHODS
  This methodological study comprised three steps: conceptualization of the IBS-HR-QOL, item extraction and establishment of content validity, and psychometric evaluation of the instrument with 267 IBS patients recruited from four university hospitals.
  
  
  RESULTS
  The content validity of the developed IBS-HR-QOL was assessed by 11 experts. Exploratory and confirmatory factor analyses yielded four factors. The criterion and convergent validities of the IBS-HR-QOL were demonstrated using the Short Form-36 and the Hospital Anxiety and Depression Scale, respectively. Known-groups validity was demonstrated using a symptom-severity scale. The internal consistency reliability and test-retest reliability were satisfactory, with a Cronbach's alpha and intraclass correlation coefficient of 0.93 and 0.88, respectively.
  
  
  CONCLUSIONS
  The IBS-HR-QOL comprises a total of 16 items. The IBS-HR-QOL demonstrated good psychometric properties. This instrument is easily comprehensible and short, rendering it feasible for use in clinical practice and research.
authors.affiliation: Graduate School of Public Health, Ajou University, 164 Worldcup-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 443-380, Republic of Korea. ehlee@ajou.ac.kr.
authors.forename: Eun-Hyun
authors.initials: EH
authors.lastname: Lee
authors.affiliation: Department of Food & Nutritional Sciences, Ewha Womans University, Seoul, Republic of Korea.
authors.forename: Oran
authors.initials: O
authors.lastname: Kwon
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea.
authors.forename: Ki Baik
authors.initials: KB
authors.lastname: Hahm
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea.
authors.forename: WonHee
authors.initials: W
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, The Catholic University of Korea, Yeouido St. Mary's Hospital, Seoul, Republic of Korea.
authors.forename: Jin Il
authors.initials: JI
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, The Catholic University of Korea, Yeouido St. Mary's Hospital, Seoul, Republic of Korea.
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Cheung
authors.affiliation: Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Yoon Jae
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea.
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea.
authors.forename: Jong-Jae
authors.initials: JJ
authors.lastname: Park
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea.
authors.forename: Moon Kyung
authors.initials: MK
authors.lastname: Joo
mesh_terms: D000328:Adult; D002908:Chronic Disease; D032882:Comprehension; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000523:psychology* / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult