Repeated measures of FEV1 over six to twelve months: what change is abnormal?

J Occup Environ Med. 2004 Jun;46(6):591-5. doi: 10.1097/01.jom.0000128159.09520.2a.


Monitoring change in FEV1 (deltaFEV1) is useful for assessing adverse respiratory effects in an individual, but high variability impedes reliable recognition of accelerated decline. The American Thoracic Society (ATS) recommends a > or =15% year-to-year FEV1 decline for clinical significance. To evaluate the applicability of this criterion in health monitoring programs, we examined the mean, lower 5th percentile, and lower 5% cutoff value of deltaFEV1 determined from 2 tests at 6- and 12-month intervals using data obtained with ATS-recommended equipment and procedures in 389 white male workers, each with 3 to 11 spirometry tests over 5 years. Results indicate that when healthy working males perform spirometry according to ATS standards, a yearly decline in FEV1 greater than 8% or 330 mL should not be considered normal, whereas the 15% ATS criterion could be appropriate in clinical settings.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Coal Mining
  • Follow-Up Studies
  • Forced Expiratory Volume / physiology*
  • Humans
  • Linear Models
  • Male
  • Methacholine Chloride
  • Middle Aged
  • Occupational Exposure / adverse effects*
  • Practice Guidelines as Topic*
  • Reference Values
  • Respiratory Function Tests
  • Smoking / adverse effects
  • Societies, Medical
  • Spirometry / standards*
  • Whites / statistics & numerical data


  • Methacholine Chloride