title: Case identification of subjects with airflow limitations using the handheld spirometer "Hi-Checker™" : comparison against an electronic desktop spirometer.
abstract: BACKGROUND
  Systematic case identification has been proposed as a strategy to improve diagnosis rates and to enable the early detection of subjects with COPD. We hypothesized that case identification could be possible using the handheld spirometer Hi-Checker™.
  
  
  OBJECTIVE
  To determine how to modify the FEV(1)/FEV(6) values obtained using the Hi-Checker™ to screen for cases with airflow limitation.
  
  
  METHODS
  Spirometry was performed with both an electronic desktop spirometer and with the Hi-Checker™ in 312 male subjects.
  
  
  RESULTS
  The average FEV(1) (mean ± SD) measured using a conventional spirometer and the Hi-Checker™ was 2.99 ± 0.56L and 3.07 ± 0.57L, respectively. These results were significantly different (P<0.001, paired t-test for both). This difference of -0.08 ± 0.13L (95% confidence interval: -0.094-0.066L) was normally distributed, and thought to be random. Statistically significant correlations were found for all measurements between the spirometer and the Hi-Checker™ ; the Pearson's correlation coefficient (R) between the FEV(1)/FVC and FEV(1)/FEV(6) values was 0.881. If one defines a FEV(1/)FVC smaller than 0.7 measured by the spirometer as airflow limitation, then a FEV(1)/FEV(6) smaller than 0.746 measured by the Hi-Checker™ best matches this definition, and Cohen's kappa coefficient was 0.672.
  
  
  CONCLUSIONS
  Although the Hi-Checker™ estimates resembled those from conventional spirometry, it should be emphasized that the two methods did not produce identical results due to random measurement error. Although one must be careful about overinterpreting these results, since the Hi-Checker™ is small and inexpensive, it could make a significant contribution in facilitating the case selection of patients with airflow limitation.
authors.affiliation: Niigata Association of Occupational Health Incorporated, Niigata, Japan. koichi-nishimura@nifty.com
authors.forename: Koichi
authors.initials: K
authors.lastname: Nishimura
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Nakayasu
authors.forename: Atsuko
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mitsuma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D012372:ROC Curve; D013147:Spirometry / Q000295:instrumentation*