Doll and Peto studied a group of British physicians who smoked and derived equations to predict the annual lung cancer incidence in the population as it aged. The study was done at the Radcliffe Infirmary at the University of Oxford in England.
Factors affecting incidence of lung cancer in cigarette smokers include:
(1) duration of smoking
(2) quantity of cigarettes smoked daily
(3) silica, uranium, asbestos and other inhaled dusts associated with pneumoconiosis
(4) radon and other radiation sources
(5) bronchitis and other chronic lung infections
In general, the cancer risk depends more on the duration of smoking than the daily dose-rate of cigarette smoking . ("Smoking 2 packs/day for 20 years is far less hazardous than smoking one pack/day for 40 years.", Finkelstein, 1998, page 248). Giving up smoking in later adult life is associated with a substantial decrease on risk 5-10 years later (Doll, 1978, page 303).
Patient criteria for equation of Doll and Peto:
(1) Patient who started smoking from between ages 16 and 25
(2) Patient smoked 1-40 cigarettes per day.
annual lung cancer incidence for ages 40-79 =
= 0.273 * 10^(-12) * (((cigarettes smoked per day) + 6)^2) * (((age in years) – 22.5)^4.5)
where:
• 0.273 * 10^(-12) is the incidence proportion
• (((cigarettes) + 6)^2) is the dose
• 4.5 as the age exponent
Alternative equations for different data approximations:
|
Model |
Incidence Proportion |
Dose |
Age Exponent |
|
curved |
1.74 * 10^(-12) |
(((daily cigarettes) + 6)^2) |
4 |
|
curved |
0.0423 * 10^(-12) |
(((daily cigarettes) + 6)^2) |
5 |
|
linear |
60.4 * 10^(-12) |
((daily cigarettes) + 1) |
4 |
|
linear |
9.46 * 10^(-12) |
((daily cigarettes) + 1) |
4.5 |
|
linear |
1.46 * 10^(-12) |
((daily cigarettes) + 1) |
5 |
Specialty: Toxicology, Emergency Medicine, Critical Care
ICD-10: ,
