title: Test-retest reliability of respiratory resistance measured with the airflow perturbation device.
abstract: OBJECTIVE
  In this study, the authors aimed to determine reliability of the airflow perturbation device (APD) to measure respiratory resistance within and across sessions during resting tidal (RTB) and postexercise breathing in healthy athletes, and during RTB across trials within a session in athletes with paradoxical vocal fold motion (PVFM) disorder.
  
  
  METHODS
  Prospective, repeated-measures design. The APD measured respiratory resistance during 3 baseline assessments in 24 teenage female athletes, 12 with and 12 without PVFM. Control athletes provided data at rest and following a customized exercise challenge during each of 3 sessions. Intraclass correlation coefficient (ICC) analysis assessed strength of relationships, and repeated-measures analysis of variance assessed differences across trials and sessions.
  
  
  RESULTS
  ICC analyses confirmed strong correlations across RTB trials for inspiratory, expiratory, and mean respiratory resistance in both groups. Inspiratory resistance decreased ~5% between sessions for control participants; expiratory and mean respiratory resistances were stable. Data from control athletes across sessions and following rigorous exercise were strongly correlated when taken at comparable intervals.
  
  
  CONCLUSIONS
  APD-measured respiratory resistance, including separate assessments for the inspiratory and expiratory phases, has strong test-retest reliability during RTB and after exercising. This suggests that the APD is a useful measurement tool for the assessment of airway function in patients suspected of having PVFM.
authors.forename: Sally K
authors.initials: SK
authors.lastname: Gallena
authors.forename: Nancy Pearl
authors.initials: NP
authors.lastname: Solomon
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Johnson
authors.forename: Jafar
authors.initials: J
authors.lastname: Vossoughi
authors.forename: Wei
authors.initials: W
authors.lastname: Tian
mesh_terms: D000293:Adolescent; D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology; D000403:Airway Resistance / Q000502:physiology*; D056352:Athletes; D016022:Case-Control Studies; D004867:Equipment Design; D015444:Exercise / Q000502:physiology; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D011446:Prospective Studies; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000295:instrumentation / Q000592:standards*; D064706:Vocal Cord Dysfunction / Q000150:complications / Q000503:physiopathology*