| Background:Bladder cancer is one of the most common malignant tumors.According to the 2015 annual report of the National Cancer Registry,bladder cancer is the sixth most common tumor in males in China,and the first frequent tumor of the urinary system.The incidence and mortality of bladder cancer in China have been increasing in recent years.This study aimed to analyze the secular trends of bladder cancer mortality in China using Joinpoint regression,find the joinpoints of bladder cancer mortality in China and estimate the independent effects of chronological age,time period and birth cohort using age-period-cohort(APC)analysis,so as to provide scientific basis for the bladder cancer prevention strategy in China.Method:Data of bladder cancer mortality between 1991 and 2015 were obtained from WHO Mortality Database and China Health Statistical Yearbook.Age-standardized mortality rates(ASMR)were calculated based on the data of the National Population Sampling Survey in 2015.The trends of ASMRs by gender were estimated by Joinpoint regression.Age-period-cohort analysis was employed to estimate the independent effects of age,time period,and birth cohort on bladder cancer mortality by the intrinsic estimator method.The parameter estimation method selected intrinsic estimator(IE)method.Stata,R and JMP software were used in the statistical analysis.The significant level was 0.05.Results:The age-standardized mortality rates(ASMRs,1/100,000)of total residents(from 2.33 to 1.87),male residents(from 3.45 to 2.89)and female residents(from 1.24 to 0.82)showed a decreasing trend in the observation period.Mortality rates were higher among male residents than that among female residents.The bladder cancer ASMRs of male residents increased lightly in recent years.The bladder cancer ASMRs of total residents showed a decreasing trend by 3.94% in the period of 1991-2005.For males,the bladder cancer ASMRs showed a decreasing trend by 6.62% in the period of 1998-2005.At the period of 2005-2009,the bladder cancer ASMRs of male residents increased 7.37% per year.And the bladder cancer ASMRs of male residents decreased in 2009-2013,with a percentage of annual change of 6.67%.The bladder cancer ASMRs of female residents showed a decreasing trend by 1.7% per year from 1991 to 2015.The age effects increased consistently with age in all age groups from 35 to 84 years in all populations(total:-2.02 to 1.91,male:-2.06 to 2.02,female:-2.04 to 1.81).The risk of bladder cancer was lower in male under 49 years old,while male over 65 and female over 69 were at greater risk of death from bladder cancer.The cohort effects decreased overall in all populations(total: 0.96 to-1.62,male: 1.11 to-1.66,female: 0.78 to-1.46).Male born before 1935 had a higher risk of death from bladder cancer.The period effect is not found in this study.Compared with other models of age-period-cohort model,the optimal model for bladder cancer mortality in China was the age-period-cohort model.Conclusion:1.The overall mortality rates of bladder cancer showed decreasing trends in China in the period 1991-2015.The bladder cancer mortality of males were higher than that in females.2.Compared with other models of age-period-cohort model,the whole model has better fitting effect on the bladder cancer mortality in China.3.The bladder cancer mortality rates increased with age and decreased with birth cohort.The period effect is not found in this study.But the cohort is a factor that affects bladder cancer mortality for male only. |
PDF Full Text Request