title: Validity and reliability of the MSKCC Bowel Function instrument in a sample of Italian rectal cancer patients.
abstract: OBJECTIVE
  The purpose of this study was to translate the Memorial Sloan Kettering Cancer Centre (MSKCC) Bowel Function Instrument into Italian and to test its psychometric validity and reliability in a sample of Italian rectal cancer patients.
  
  
  METHODS
  The MSKCC questionnaire was translated into Italian using a standard procedure of double-back translation. Construct validity was tested using a factor analysis and internal reliability was estimated using the Cronbach's alpha coefficient. Concurrent validity was determined by correlations with European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 quality of life scales. A non-parametric analysis of variance was used to establish the discriminant validity of the questionnaire. Test-retest reliability was assessed using the intra-class correlation coefficient.
  
  
  RESULTS
  124 rectal cancer patients participated in the validation study. The number of missing items was 2.2%. The factorial structure was found to be quite similar to the original one and the internal reliability was 0.7 for urgency, 0.6 for frequency, and 0.7 for dietary subscale. The test-retest reliability was acceptable with one exception: the dietary subscale showed a low reproducibility (ICC = 0.4). All three subscales showed a significant correlation with the QLQ-C30 and QLQ-CR38 domains and were able to discriminate several groups of clinical relevance.
  
  
  CONCLUSIONS
  The Italian version of the MSKCC Bowel Function Instrument shows acceptable psychometric properties and can be considered a valuable and specific instrument to assess bowel functions in rectal cancer patients, both for research purposes and in clinical practise.
authors.affiliation: Department of Clinical-Specialty Services & Support, National Cancer Institute CRO, Aviano, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Zotti
authors.forename: P
authors.initials: P
authors.lastname: Del Bianco
authors.forename: S
authors.initials: S
authors.lastname: Serpentini
authors.forename: P
authors.initials: P
authors.lastname: Trevisanut
authors.forename: M C
authors.initials: MC
authors.lastname: Barba
authors.forename: V
authors.initials: V
authors.lastname: Valentini
authors.forename: A
authors.initials: A
authors.lastname: De Paoli
authors.forename: S
authors.initials: S
authors.lastname: Pucciarelli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001828:Body Image; D003672:Defecation / Q000502:physiology; D013505:Digestive System Surgical Procedures / Q000009:adverse effects*; D005242:Fecal Incontinence / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007422:Intestines / Q000503:physiopathology*; D007558:Italy; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D012004:Rectal Neoplasms / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D015203:Reproducibility of Results; D012735:Sexual Dysfunction, Physiological / Q000523:psychology; D011795:Surveys and Questionnaires