What is the proportion of lung cancer deaths among all smokers that can be attributed to smoking? What is the proportion of lung cancer deaths in the total population that can be attributed to smoking? Assume that the mortality from lung cancer in the total population is 0.94 x 1,000 person-years.

Table 4 shows the mortality rate x 1,000 person-years and rate ratio of mortality for non-smokers, ex-smokers (according to the number of years since quit smoking) and smokers:

* Tabla 4. Tasa de mortalidad y razn de tasas segn el hbito de tabaquismo Muertes Tasa x 1,000 Razn aos-persona de tasas No fumadores 3 0.07 1.0 Ex-fumadores (aos desde que dej de fumar) 20 aos 2 0.19 2.7 Fumadores actuales 133 1.30 18.5 *Grupo de referencia * Tabla 4. Tasa de mortalidad y razn de tasas segn el hbito de tabaquismo Muertes Tasa x 1,000 Razn aos-persona de tasas No fumadores 3 0.07 1.0 Ex-fumadores (aos desde que dej de fumar) 20 aos 2 0.19 2.7 Fumadores actuales 133 1.30 18.5 *Grupo de referencia