Survival Time Analysis Of The Silicosis Patients In A Copper Mine

Objective:To analyze the survival time and main influencing factors on the death silicosis in a copper mine.Methods:Retrospective analysis carried out on the death among217ilicosis patients from December2005to June2010.all silicosis patients were sampled as study participants in the Tongling Nonferrous Metals Second Hospital (Occupational Disease Treatment Centers), calculation was made on the actual length of exposed to dust, age of exposed to dust, incidence ages of pneumoconiosis, times of exposed to dust and post-pneumoconiosis life span (survival time), disease stage, number of complications, etc. Survey data were analyzed with statistical analysis software of SPSS13.0.The survival time and main influencing factors were studied with Kaplan-Meier and Cox Regression.Results:217pneumoconiosis cases, male216cases, female1cases, were underground mining; mean age75.7±5.7years old; drilling engineering in97cases, accounting for44.7%; transportation work in62cases, accounting for28.6%; blasting in16cases, accounting for7.4%; pillar industry in17cases, accounting for7.8%; other25cases with mine, accounted for11.5%. Ⅰ period of169cases of silicosis, accounted for77.88%; Ⅱ period of33cases of silicosis, accounted for15.2%; Ⅲ period of15cases of silicosis6.91%,Average time of exposure for22.73years, a minimum of2years, a maximum of38years. The average age was57.94years old, minimum25, maximum65years. The average dust age23years, minimum12years, maximum38years.Average latency period of34years, a minimum of3years, a maximum of62years. Ⅰ incidence of tuberculosis in17.8%, Ⅱ incidence of tuberculosis in25%, Ⅲ tuberculosis incidence rate20%; between each period of tuberculosis morbidity compared with no statistical significance (X24.356,P>0.05). The average incidence of lung cancer in20.7%, which I silicosis incidence rate of lung cancer in17.8%, Ⅱ silicosis incidence rate of lung cancer in36.4%, Ⅲ silicosis incidence rate of lung cancer20%. Between each period the incidence of lung cancer in comparison with statistical significance (X2=5.824,P0.05). I phase silicosis survival time (=death time-Ⅰ diagnosis time) for17.4years on average, median survival time (P25, P75) for1years (12.2,21.8); Ⅱ phase silicosis survival time (=death time-Ⅱ diagnosis time) for21years on average, median survival time (P25, P75) to22(20.1,23.9); Ⅲ phase silicosis survival time (=death time-Ⅲ diagnosis time) for18.8years on average, median survival time (P25, P75) for23years (16.4,29.6). The means age of exposed to dust is22.73±0.3289a,The means of length of exposed to dust is23.0±0.32years,The means of incidence ages of pneumoconiosis is57.94±0.905a, Median post-pneumoconiosis life span (survival time)(P25,P75) is17.35(12.2,21.7) years.COX proportional hazards model regression analysis determine Phase I diagnostic age x1, Exposure ageX2, age of onset X3, as the independent variables are statistically significant variables to construct equation, regression equation:λ(T)=λ0(T) exp (2.523X1-0.088X2+0.103X3). By the COX model equations can be derived for each variable relative risk (RR) value. The variable I diagnosis time RR12.468, each forward a time (10years) in a moment of silicosis patients death of RR increased by12.468times; Exposure age coefficientβ-0.088, RR0.916, that age were protective factors of dust, dust age increase every1years at some point, silicosis patient death of RR increased by0.916times; the age of onset of RR1.109, age of onset of increase of1per year, a moment of silicosis patients death of RR increased1.109times. Actual time of exposure, with lung cancer, complicated with tuberculosis, jobs and variable into the equation. Conclusion:Survival analysis method is effective in treatment of silicosis death cases of pneumoconiosis patients survival; the survival time is influenced by many factors, I diagnosis time, exposure age, age of onset, Complication is a comprehensive analysis of pneumoconiosis development law, evaluate the control effect of the main parameters. Silicosis prevention properly, can obtain average or higher life expectancy. Different diagnostic age of silicosis death causes changes closer to the diagnosis of s silicon tuberculosis has declined, pneumoconiosis, pulmonary heart disease, lung cancer has increased. Silicosis incidence age increasingwhich brings new social problems.