Article Text

Download PDFPDF
Decline in lung function and mortality: implications for medical monitoring
  1. Kanta Sircar,
  2. Eva Hnizdo,
  3. Edward Petsonk,
  4. Michael Attfield
  1. National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
  1. Correspondence to:
 Dr K Sircar
 National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA; KSircar{at}


Aim: To investigate the risk of death associated with selected cut-off points for rate of decline of forced expiratory volume in one second (FEV1).

Methods: Mortality rates of a cohort of 1730 coal miners who had performed two pulmonary function tests 12.8 years apart were followed up for an additional 12 years. Based on previous studies, cut-off points for FEV1 rate of decline (ml/year) were selected as 30, 60 and 90 ml/year. Cox proportional hazard regression was used to estimate multivariate risk ratio of death in each category.

Results: The risk ratios (compared to “below 30 ml/year”) were 1.39 (95% CI 0.99 to 1.97) in the “60 to less than 90 ml/year” category and 1.90 (95% CI 1.32 to 2.76) in the “90 ml/year and above” category. Rates of decline above 90 ml/year were consistently related to excess mortality. In non-smokers and those with neither restrictive nor obstructive patterns at the first survey, rates of decline above 60 ml/year were significantly associated with increased mortality.

Conclusions: Risk of death increases in individuals with rates of decline above about 60 ml/year and is statistically significant with declines of 90 ml/year or more. These results should be useful to healthcare providers in assessing lung function declines observed in individuals.

  • ATS, American Thoracic Society
  • BMI, body mass index
  • FEV1, forced expiratory volume in one second
  • ICD-9, International Classification of Diseases Ninth Revision
  • NSCWP, National Study of Coal Workers’ Pneumoconiosis
  • PFT, pulmonary function test

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Published Online First 1 March 2007

  • Funding: National Institute for Occupational Safety and Health.

  • Competing interests: None.

  • The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.