title: Inter- and intra-observer variability of ultrasonographic arm muscle thickness measurement by critical care physicians.
abstract: OBJECTIVE
  The aim of this study was to assess inter- and intra-observer variability of arm muscle thickness measured by critical care physicians using bedside ultrasonography (USG).
  
  
  METHODS
  This prospective study included twenty patients admitted with sepsis. Three measurements of thickness of right arm muscles of each patient using B-mode USG were taken by two critical care fellows, independently. Intra- and inter-observer reliability was tested using intraclass correlation coefficient (ICC).
  
  
  RESULTS
  The mean 1st, 2nd, and 3rd measurements of muscle thickness recorded by observer 1 and 2 were 23.620 (±4.171) versus 23.840 (±3.849) mm, 23.235 (±3.620) versus 23.625 (±4.062) mm, and 24.125 (±4.098) versus 23.965 (±3.651) mm, respectively. The average muscle thickness measured by first and second observer was 23.660 (±3.834) mm and 23.810 (±3.674) mm, respectively. ICC for intra-observer variability for observer 1 and 2 was 0.964 (95% confidence interval [CI] 0.924-0.985) and 0.949 (95% CI 0.892-0.978), respectively. ICC for inter-observer variability was 0.995 (95% CI 0.988-0.998).
  
  
  CONCLUSIONS
  USG is a reliable tool for assessment of arm muscle thickness by critical care physicians.
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: V
authors.initials: V
authors.lastname: Hadda
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: A
authors.initials: A
authors.lastname: Dhungana
authors.affiliation: Department of Biostatistics, All Institute of Medical Sciences, New Delhi, India.
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: K
authors.initials: K
authors.lastname: Madan
authors.affiliation: Department of Pulmonary Medicine and Sleep Disorders, All Institute of Medical Sciences, New Delhi, India.
authors.forename: G C
authors.initials: GC
authors.lastname: Khilnani
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D003422:Critical Care; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010820:Physicians; D000067716:Point-of-Care Testing; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D018805:Sepsis / Q000503:physiopathology / Q000628:therapy*; D014463:Ultrasonography