Metrics details. For quitters, quit-years and corresponding RRs were used, and the pooled dichotomous RR value was used as the starting point to avoid overestimation. A total of 12 studies were included.
In all models, less than 60 pack-years presented RRs below For former smokers, the RR decreased to 1 when quit-years reached up to 7 years. The risk of lung cancer mortality rose with pack-years and decreased with quit-years among Chinese adults, and both values were far below global level.
The results suggested that the doseβresponse RR of lung cancer deaths associated with smoking in China should be estimated separately. Peer Review reports. China has a large number of smokers, up to million in [ 3 ]. Moreover, the mortality rate of lung cancer is still on the rise in China, which ranks first in both morbidity and mortality rates from malignant tumors [ 4 ]. In , there were approximately , diagnosed patients and , deaths due to lung cancer in China [ 5 ].
There is a lag effect of smoking exposure on cancer, and although smoking prevalence in the general Chinese population has declined over the past three decades, a study predicted that smoking-related mortality would continue to surge in the next 20 years [ 6 ]. The high exposure to cooking oil fumes and biomass fuels has competing effects on the Chinese population due to burning coal for domestic heating and the unique cooking style in China.
Therefore, the relative risks RRs of smoking-attributable diseases were significantly different in China compared with those in developed countries [ 7 , 8 , 9 ].
