title: Reliability and accuracy of cirtometry in healthy adults.
abstract: OBJECTIVE
  To determine the intrarater and interrater reliability of cirtometry (measurements of the circumference of the chest and abdomen taken during respiratory movements) as well as its correlation with pulmonary volumes measured by respiratory inductive plethysmography.
  
  
  METHODS
  A total of 40 healthy individuals were evaluated. The mean age was 28 years. The measurements were taken in the supine position at three different time points: at rest, at maximal inspiration, and at maximal expiration. Two trained investigators, each of whom was blinded as to the results obtained by the other, performed the measurements. The Friedman test was used to determine intrarater reliability, and the Wilcoxon test, together with the intraclass correlation coefficient, were used to determine interrater reliability. The correlation between the cirtometry measurements and the plethysmography results was obtained using Spearman's correlation coefficient. The level of significance was set at 0.05 for all tests.
  
  
  RESULTS
  Intrarater reliability was satisfactory. Regarding interrater reliability, statistically significant differences (2.8 cm at the most) were found in all sets of measurements. However, through the analysis of the intraclass correlation coefficient, the investigators were found to be responsible only for a small portion of the variability (1.2-5.08%) found among the measurements. When the cirtometry measurements were compared to the volumes measured by respiratory inductive plethysmography, low correlations (range, r = 0.170-0.343) were found.
  
  
  CONCLUSIONS
  The findings of this study suggest that, although cirtometry is a reliable measurement, it does not accurately measure pulmonary volumes.
authors.affiliation: Universidade Federal de Minas Gerais -UFMG, Federal University of Minas Gerais - Belo Horizonte (MG) Brazil.
authors.forename: Valéria da Silva
authors.initials: Vda S
authors.lastname: Caldeira
authors.forename: Célia Cristina Duarte
authors.initials: CC
authors.lastname: Starling
authors.forename: Raquel Rodrigues
authors.initials: RR
authors.lastname: Britto
authors.forename: Jocimar Avelar
authors.initials: JA
authors.lastname: Martins
authors.forename: Rosana Ferreira
authors.initials: RF
authors.lastname: Sampaio
authors.forename: Verônica Franco
authors.initials: VF
authors.lastname: Parreira
mesh_terms: D000005:Abdomen / Q000033:anatomy & histology*; D000328:Adult; D000886:Anthropometry / Q000379:methods*; D001365:Axilla; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008792:Metric System / Q000295:instrumentation / Q000592:standards*; D008875:Middle Aged; D010991:Plethysmography / Q000592:standards*; D015203:Reproducibility of Results; D012119:Respiration; D012146:Rest; D013147:Spirometry; D018709:Statistics, Nonparametric; D013909:Thorax / Q000033:anatomy & histology*; D014472:Umbilicus; D014989:Xiphoid Bone