When is FEV1 loss excessive? - An investigation of the relationship between year-to-year and long-term spirometry changes.
Wang ML; Avashia B; Petsonk EL
Eur Respir J 2004 Sep; 24(48):434S
Spirometry is performed to monitor lung health, but variability between tests can hinder recognition of excessive FEV1 declines. We explored the relationship between year-to-year and long-term (average 18 yrs) FEV1 slopes, using 21,821 results from 1,884 workers who participated in annual spirometry at a chemical plant between 1973 and 2003. Workers with >/=5 valid results over >/= 10 years were included (initial age: mean 35, range 18-62 yrs; 91% male; 35% current smokers, 41% nonsmokers). Long-term FEV1 slopes (ml/yr) were calculated for each worker by simple linear regression using all available results, and compared to year-to-year differences (deltaFEV1) in both % and milliliters. Long-term slopes averaged -29.1 ml/yr (-27, -29, -37 ml/yr for male, and -20, -26, and -27 ml/yr for female non-, ex- and cur- smokers, respectively). Excessive long-term decline was defined by the lower 5th%ile of all individual slopes, -68.0 ml/yr. When interpreting yearly FEV1 change using the 5th%ile of deltaFEV1 (-10% or -360 ml) as normal limits, individuals with abnormal short-term declines are more likely to ultimately show excessive long-term declines (odds ratio=3.8).
Pulmonary-system-disorders; Pulmonary-disorders; Respiratory-system-disorders; Mortality-rates; Mortality-data; Mortality-surveys; Epidemiology; Statistical-analysis; Spirometry; Lung-function; Pulmonary-function; Pulmonary-function-tests; Surveillance
Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV
European Respiratory Journal. 14th ERS Annual Congress, Glasgow, UK, September 4-8, 2004