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.
吸烟者的肺癌发病率与剂量率(每天吸烟的支数)大致成正比,但随着吸烟时间的延长,发病率增加得更快。多年来,人们已经知道,发病率与终生总剂量(剂量率与吸烟时间的乘积)成正比的假设是错误的,但在对流行病学数据进行回归分析时,仍经常单独或与更基本的参数(如剂量率)一起使用以年包数表示的总剂量。这在数学上是不必要的,在科学上也没有帮助。