Back to Conference page
The 13th World Conference on Tobacco OR Health
Building capacity for a tobacco-free world
July 12-15, 2006, Washington, DC, USA
Objective: The objective of this study was to describe trends in the incidence rates from primary lung cancer in a geographically defined Chinese population.
Methods: Primary lung cancer cases (N=39,731) diagnosed between 1981 and 2000 were identified by the Tianjin Cancer Registry, which covers a population of five million. Age-sex specific incidence rates were calculated. Age-adjusted incidence rates were calculated using the world standard population. The coefficient for each term was the log-scaled relative risk. Age, period, and cohort (APC) effects were fitted in log-linear models. As the incidence rates of lung cancer are very low before 40 years of age, they were not included in the APC model. The maximum likelihood method was performed to estimate the parameters associated with the APC model. The goodness-of-fit for the specified model was measured by deviance defined as twice the difference between the log-likelihood of a perfectly fitting model and the current model. The SAS PROC GENMOD was used for model fitting.
Results: Resulte shows that over the 20-year study period (1981 to 2000), 40,022 lung cancer cases were identified; 58.5% occurred in males. The mean age at diagnosis for the study population was 65.0 years (S.D.=10.3 years), with no difference between males and females (65.0 and 65.1 years for males and females, respectively). Also, in the APC model, using 1981-85 as a baseline incidence rates were higher for later periods, particularly in men.