| ObjectiveWith mortality data in National Retrospective Surveys on Mortality and Routine Death Registration System (DRS), we explore the tendency in mortality of lung cancer in Xuanwei. Also, a survey was conducted in Xuanwei exploring residents’ exposure to risk factors of lung cancer currently and ten years ago in varied regions.Materials and Methods1. Study on mortality of lung cancer:Mortality data are collected in Xuanwei during the 2nd and 3rd National Retrospective Sampling Survey and DRS during 2011-2013. A survey on under-reported death was conducted in 30 villages in Xuanwei to evaluate completeness of data from DRS. Mortality data from DRS were adjusted for under-reported rates of death stratified by regions. With these data, disease-specified mortality rate, ASMR and 45Q15 were calculated and compared with those in rural areas in China.2. Survey on risk factors of lung cancer:Totally 24 villages in 6 towns were selected in high-mortality, median-mortality and low-mortality regions. Participants were asked about their exposure to main risk factors of lung cancer, including occupational history, use of stoves and fuels, dietary factors, smoking and second-hand smoking, drinking, history of disease, et al. Prevalence of risk factors of lung cancer was descript and compared in these three regions.Results1. The completeness of mortality data from DRS in Xuanwei needs improvement. Total under-reported rate of death during 2011-2013 was 31.88%. In high-mortality, medium-mortality and low-mortality regions, under-reported rates were 17.48%,38.01% and 36.22% respectively with a significant difference (x2=213.25, P<0.001). After adjustment of data from DRS stratified by regions, during three periods,1990-1992, 2004-2005 and 2011-2013, lung cancer contributed to 56.86%,58.45% and 63.03% of deaths from all cancers respectively which kept at high levels and are much higher than those in rural areas nationally. The ASMR of lung cancer of males surged from 41.43/105 to 88.17/105 during 1990-2005 and it surged from 37.70/105 to 74.45/105 for females. Although it declined slightly during 2011-2013 with ASMR of 82.53/105 and 62.52/105 for males and females respectively, it was three times of that in rural areas in China among males and six times for females. The 45Q15 of lung cancer for males in Xuanwei was 3-5 times of that in rural areas of China and for females it was 7-9 times. The high-mortality areas of lung cancer were located in Laibin, Longchang, Wanshui and Shuanglong Communities. The differences in mortality rates of lung cancer did not change regionally. High-mortality areas of lung cancer expanded to their surrounding areas and those in southeast.2. Among 2346 participants in the survey on risk factors of lung cancer, more than 50% of participants used smoky coal and very few of them used unvented fire pit. More than 60% of males ever smoked and nearly 50% of all participants heavily exposed to second-hand smoking. Consumption of vegetables, smoking rate and exposure rate to second-hand smoking in high-mortality regions were higher than those in low-mortality regions. Compared with the situation a decade ago, residents consumed less smoky coal and firewood, but more electricity. More residents used portable stoves or electric heater and fewer of them used unvented fire pit or vented pit furnace with small proportions in high-mortality areas than low-mortality areas.ConclusionsWith mortality data evaluated by completeness, patterns of death in Xuanwei were explored. During the past two decades, as a long-known high-mortality area of lung cancer, patterns of total mortality in Xuanwei have changed. Although interventions have been conducted on indoor air pollution caused by smoky coal and main risk factors have been controlled, mortality rate of lung cancer in Xuanwei kept increasing and stayed at a high level. Also, characteristics of lung cancer mortality have not obviously changed. Therefore further study should be conducted to explore risk factors of lung cancer in Xuanwei comprehensively. |
PDF Full Text Request