The Assessment of Airway Resistance and Airtrapping in Elderly COPD Patients by Forced Oscillation Technique (FOT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01553812
Recruitment Status : Completed
First Posted : March 14, 2012
Last Update Posted : March 14, 2012
Information provided by (Responsible Party):
Tse Hoi Nam, Kwong Wah Hospital

Brief Summary:
The study hypothesize that parameters of new function machine---'forced oscillation technique' (FOT) can correlate well with the conventional lung function data for measurement of airway resistance and airtrapping in elderly COPD patients.

Condition or disease

Detailed Description:


Forced oscillation technique (FOT) may be a good supplementary tool to assess lung function in elderly since it is a simple and fast tool requiring minimal patients' cooperation.


To investigate the accuracy of forced oscillation test FOT in assessment of airway resistance and airtrapping in elderly COPD patients by comparing FOT parameters to various conventional lung function parameters including FEV1, FEF 25-75, RV/TLC ratio, IC etc. The best FOT parameter for airway resistance and airtrapping is also determined.


A cross-sectional study conducted in Kwong Wah Hospital, Hong Kong, SAR


COPD patients were recruited from 1st Jan, 2010 to 31st Dec 2011. Both of the lung function tests (forced oscillation technique (FOT) and conventional lung function test) were performed. Parameters of FOT (FRes FDep, RAvr, XAvr, were compared with conventional lung function test for assessment of both airway resistance and airtrapping in COPD subjects. Adjusted FOT parameters (FResRatio and FDep) were also compared with %FEV1 and different GOLD stages.


Comparison between FOT parameters and spirometric parameters was done by correlation test and expressed as Spearman coefficient. ANOVA test is used to compare FOT parameters among different groups of GOLD stages (stage 1 to 4) and groups with various degree of airtrapping (stage 1 to 3). Post hoc analysis was estimated by Bonferroni test.

Study Type : Observational
Actual Enrollment : 158 participants
Time Perspective: Cross-Sectional
Official Title: The Assessment of Airway Resistance and Airtrapping in Elderly COPD Patients by Forced Oscillation Technique (FOT)
Study Start Date : January 2010
Actual Primary Completion Date : December 2011
Actual Study Completion Date : December 2011

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Ages Eligible for Study:   60 Years to 90 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
COPD patients from both 'in-patient' and 'outpatient clinic' in Kwong Wah Hospital, Hong Kong, China

Inclusion Criteria:

  • COPD patients with previous lung function tests confirming irreversible obstructive pattern

Exclusion Criteria:

  • Lung function test failed to show any obstructive pattern
  • Paitents with co-existing pulmonary diseases including asthma, interstitial lung diseases, lung malignancy etc.
  • Patients with active infectious diseases like tuberculosis

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Tse Hoi Nam, Resident Specialist, Kwong Wah Hospital Identifier: NCT01553812     History of Changes
Other Study ID Numbers: KW/EX-12-030 (48-15)
First Posted: March 14, 2012    Key Record Dates
Last Update Posted: March 14, 2012
Last Verified: March 2012

Keywords provided by Tse Hoi Nam, Kwong Wah Hospital:
forced oscillation technique
airway resistance