That the effects of smoking should be measured in pack-years: misconceptions 4

Br J Cancer. 2012 Jul 24;107(3):406-7. doi: 10.1038/bjc.2012.97.


Lung cancer incidence in smokers is roughly proportional to dose rate (cigarettes per day) but increases much more rapidly with duration of smoking. The assumption that the incidence rate is proportional to total lifetime dose (the product of dose rate and duration) has been known to be wrong for many years, but total dose in pack-years is still often included, either alone or together, with more fundamental parameters such as dose rate, in regression analysis of epidemiological data. This is mathematically unnecessary and scientifically unhelpful.

Publication types

  • Editorial

MeSH terms

  • Environmental Exposure / adverse effects
  • Environmental Exposure / statistics & numerical data*
  • Humans
  • Incidence
  • Lung Neoplasms / epidemiology*
  • Lung Neoplasms / etiology
  • Risk Factors
  • Smoking / adverse effects
  • Smoking / epidemiology*