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The natural variability in forced expiratory volume in one second (FEV1) over 20 minutes was determined in 54 fit hospital employees and 13 patients with restrictive lung disorders. Initial FEV1 ranged from 1.1 to 6.3 1 BTPS. Variability when expressed as absolute change was similar at all levels of FEV1, so that, when expressed as percentage change, variability decreased with increasing FEV1. Smoking habits did not appear to affect variability but activity before the test did. On the basis of these results an absolute change in FEV1 of 190 ml would be necessary for 95% confidence that the change in FEV1 occurred other than by chance in any one individual. This suggests that the absolute change in FEV1 might be a more reliable criterion than percentage change when distinguishing between natural variability and a response to inhalation of bronchodilators.
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
January 1997,
Cardiology,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
October 1989,
The European respiratory journal,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
July 1987,
Thorax,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
September 1993,
The Science of the total environment,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
January 1987,
Sozial- und Praventivmedizin,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
June 1994,
The European respiratory journal,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
April 1994,
British journal of urology,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
August 1991,
The American review of respiratory disease,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
May 1989,
Thorax,
P M Tweeddale, and
S Merchant, and
M Leslie, and
F Alexander, and
G J McHardy
January 1972,
La Prensa medica mexicana,
