title: Psychometric properties of the Persian version of the Mishel's Uncertainty in Illness Scale in patients with cancer.
abstract: OBJECTIVE
  Uncertainty is a major component in the illness experiences which extraordinarily can affect the psychological adjustment and the illness outcomes. Uncertainty in illness is defined as inability to define the illness-related events to the illness or disability in predicting the illness outcomes. The present study aimed to translate the Persian version of Uncertainty in Illness Scale (MUIS-A) and to investigate its psychometric properties on patients with cancer.
  
  
  METHODS
  In this methodological study, validation of the Persian version of MUIS-A was performed in Iran on 420 cancer patients attending two major hospitals in Tehran, Iran. The scale was translated into Persian and back translated into English and revised according to editorial comments of the scale designers. Then, content and face validity, construct validity, internal consistency reliability and stability of the Persian version were measured. Data were analyzed using SPSS version 16 and LISREL 8.5.
  
  
  RESULTS
  Mean of the participants MUIS-A score was 90.1 (16.8). Confirmatory factor analysis confirmed validity of the whole instrument and its four subscales. The consistency of the instrument with a three-week interval was r = 0.91. Cronbach's alpha was 0.89 for the whole scale of 32 MUIS-A items and α = 0.58-0.86 for its four factors.
  
  
  CONCLUSIONS
  The Persian version of the MUIS-A has good psychometric properties. It can be used to assess uncertainty in illness in Iranian patients with cancer.
authors.affiliation: Nursing & Midwifery School, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Gonabad University of Medical Sciences, Gonabad, Iran.
authors.forename: Moosa
authors.initials: M
authors.lastname: Sajjadi
authors.affiliation: Nursing & Midwifery School, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Pediatric Nursing Department, Nursing & Midwifery School, Shahid Beheshti University of Medical Sciences, Vali-e Asr Street, Niyayesh Cross, Tehran, Iran. Electronic address: Rassouli.m@gmail.com.
authors.forename: Maryam
authors.initials: M
authors.lastname: Rassouli
authors.affiliation: Department of Nursing, Nursing & Midwifery School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Abbaszadeh
authors.affiliation: Department of Biostatistics, School of Paramedical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Alavi Majd
authors.affiliation: Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Zendehdel
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D000368:Aged; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis / Q000523:psychology*; D011594:Psychometrics / Q000379:methods*; D036301:Qualitative Research; D012720:Severity of Illness Index; D014175:Translating; D055815:Young Adult
keywords: Cancer; Confirmatory factor analysis; MUIS-A; Psychometrics; Uncertainty in illness