Survival Analysis of Coal Workers’ Pneumoconiosis (CWP) Patients in a State-Owned Mine in the East of China from 1963 to 2014
Abstract
:1. Introduction
2. Materials and Methods
2.1. Subjects
2.2. Data Source
2.3. Definition of Death Cause and Censored Data
2.4. Statistical Analysis
3. Results
3.1. Death Probability of CWP Patients in Different Age Groups
3.2. Life Expectancy of CWP Patients in Different Age Groups
3.3. Effects of Several Major Causes of Death on Life Expectancy of CWP Patients
3.4. Comparison of Survival Curves between CWP Patients with Pulmonary Tuberculosis and Patients without Pulmonary Tuberculosis
3.5. Cox Model Analysis of Factors Influencing Survival Life of CWP Patients
4. Discussion
5. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
- Greenberg, M.I.; Waksman, J.; Curtis, J. Silicosis: A review. Dis. Mon. 2007, 53, 394–416. [Google Scholar] [CrossRef] [PubMed]
- Fernandez Alvarez, R. Guidelines for the diagnosis and monitoring of silicosis. Arch. Bronconeumol. 2015, 51, 86–93. [Google Scholar] [CrossRef] [PubMed]
- Merget, R. Health hazards due to the inhalation of amorphous silica. Arch. Toxicol. 2002, 75, 625–634. [Google Scholar] [CrossRef] [PubMed]
- Hedlund, U. Exposure-Response of silicosis mortality in Swedish iron ore miners. Ann. Occup. Hyg. 2008, 52, 3–7. [Google Scholar] [PubMed]
- Napierska, D. The nanosilica hazard: Another variable entity. Part. Fibre Toxicol. 2010, 7, 39. [Google Scholar] [CrossRef] [PubMed]
- Honma, K. Proposed criteria for mixed-dust pneumoconiosis: Definition, descriptions, and guidelines for pathologic diagnosis and clinical correlation. Hum. Pathol. 2004, 35, 1515–1523. [Google Scholar] [CrossRef] [PubMed]
- Zhang, M. Silicosis in automobile foundry workers: A 29-year cohort study. Biomed. Environ. Sci. 2010, 23, 121–129. [Google Scholar] [CrossRef]
- Wang, X.T. Prevalence of pneumoconiosis in a coal enterprise from 2002 to 2013. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2016, 34, 681–682. (In Chinese) [Google Scholar] [PubMed]
- Park, H.H. Incidence of tuberculosis and HIV and progression of silicosis and lung function impairment among former Basotho gold miners. Am. J. Ind. Med. 2009, 52, 901–908. [Google Scholar] [CrossRef] [PubMed]
- Shen, F. Risk identification and prediction of coal workers’ pneumoconiosis in Kailuan Colliery Group in China: A historical cohort study. PLoS ONE 2013, 8, e82181. [Google Scholar] [CrossRef] [PubMed]
- Attfield, M.D.; Kuempel, E.D. Mortality among U.S. underground coal miners: A 23-year follow-up. Am. J. Ind. Med. 2008, 51, 231–245. [Google Scholar] [PubMed]
- Soutar, C.A. Dust concentrations and respiratory risks in coalminers: Key risk estimates from the British Pneumoconiosis Field Research. Occup. Environ. Med. 2004, 61, 477–481. [Google Scholar] [CrossRef] [PubMed]
- Tomaskova, H. Cancer incidence in Czech black coal miners in association with coalworkers’ pneumoconiosis. Int. J. Occup. Med. Environ. Health 2012, 25, 137–144. [Google Scholar] [CrossRef] [PubMed]
- Hosgood, H.D., 3rd. Coal mining is associated with lung cancer risk in Xuanwei, China. Am. J. Ind. Med. 2012, 55, 5–10. [Google Scholar] [CrossRef] [PubMed]
- Mo, J. Prevalence of coal workers’ pneumoconiosis in China: A systematic analysis of 2001–2011 studies. Int. J. Hyg. Environ Health 2014, 217, 46–51. [Google Scholar] [CrossRef] [PubMed]
- Chen, W. Long-Term exposure to silica dust and risk of total and cause-specific mortality in Chinese workers: A cohort study. PLoS Med. 2012, 9, e1001206. [Google Scholar] [CrossRef] [PubMed]
- Xiao, L.C. Retrospective survey on 957 death cases of coal workers pneumoconiosis. J. Environ. Occup. Med. 2005, 22, 432–444. [Google Scholar]
- Shi, C.B. Analysis of life expectancy and death causes of CWP patients in high altitude area. J. Med. Qinghai 2000, 30, 17–20. [Google Scholar]
- Oyunbileg, S. Health impact of pneumoconiosis in Mongolia: Estimation of losses in life expectancy and quality adjusted life expectancy. Am. J. Ind. Med. 2011, 54, 285–292. [Google Scholar] [CrossRef] [PubMed]
- Centers for Disease Control and Prevention. Coal workers’ pneumoconiosis-related years of potential life lost before age 65 years—United States, 1968–2006. MMWR Morb. Mortal. Wkly. Rep. 2009, 58, 1412–1416. [Google Scholar]
- Zhang, Q. Investigation and analysis of 1153 CWP cases. Chin. Occup. Med. 2004, 31, 57–58. [Google Scholar]
- Song, Q.R. Analysis on death causes and influential factors in coal workers with pneumoconiosis. Chin. J. Public Health 2008, 24, 488–489. [Google Scholar]
- Donroe, J.A. Surveillance for early silicosis in high altitude miners using pulse oximetry. Int. J. Occup. Environ. Health 2008, 14, 187–192. [Google Scholar] [CrossRef] [PubMed]
- Kambouchner, M.; Bernaudin, J.F. The pathologist’s view of silicosis in 1930 and in 2015. The Johannesburg Conference legacy. Am. J. Ind. Med. 2015, 58, S48–S58. [Google Scholar] [CrossRef] [PubMed]
- Tse, L.A. Prediction models and risk assessment for silicosis using a retrospective cohort study among workers exposed to silica in China. Sci. Rep. 2015, 5, 11059. [Google Scholar] [CrossRef] [PubMed]
- Shen, F. Cost-Effectiveness of Coal Workers’ Pneumoconiosis Prevention Based on Its Predicted Incidence within the Datong Coal Mine Group in China. PLoS ONE 2015, 10, e0130958. [Google Scholar] [CrossRef] [PubMed]
- Han, L. Prevalence Characteristics of Coal Workers’ Pneumoconiosis (CWP) in a State-Owned Mine in Eastern China. Int. J. Environ. Res. Public Health 2015, 12, 7856–7867. [Google Scholar] [CrossRef] [PubMed]
Variable Name | Assignment Description |
---|---|
Initial dust exposure year (X1) | Continuous variable |
Dust exposure years (X2) | Continuous variable |
Age of onset (X3) | Continuous variable |
Time since first exposure (X4) | Continuous variable |
First diagnostic stage (X5) | Object of observation = 0, Stage I = 1, Stage II = 2, Stage III = 3 |
Work type (X6) | Mining = 1, Transportation assistance = 0 |
Complicated with pulmonary tuberculosis or not (X7) | Yes = 1, No = 0 |
Age Groups | Observed Patients 1 | Surviving Patients 2 | Died Patients 3 | Cumulatively Observed Patients 4 | Corrected Observed Patients 5 | Mortality Rate 6 | Survival Rate 7 | Cumulatively Survival Rate | Cumulatively Mortality Rate | Death Probability |
---|---|---|---|---|---|---|---|---|---|---|
25~ | 6 | 4 | 2 | 495 | 493 | 0.0041 | 0.9959 | 0.9959 | 0.0041 | 0.0201 |
30~ | 21 | 17 | 4 | 489 | 480.5 | 0.0083 | 0.9917 | 0.9877 | 0.0123 | 0.0408 |
35~ | 65 | 43 | 22 | 468 | 446.5 | 0.0493 | 0.9507 | 0.9390 | 0.0610 | 0.2193 |
40~ | 83 | 51 | 32 | 403 | 377.5 | 0.0848 | 0.9152 | 0.8594 | 0.1406 | 0.3497 |
45~ | 71 | 61 | 10 | 320 | 289.5 | 0.0345 | 0.9655 | 0.8297 | 0.1703 | 0.1590 |
50~ | 78 | 62 | 16 | 249 | 218 | 0.0734 | 0.9266 | 0.7688 | 0.2312 | 0.3101 |
55~ | 71 | 69 | 2 | 171 | 136.5 | 0.0147 | 0.9853 | 0.7575 | 0.2425 | 0.0707 |
60~ | 37 | 35 | 2 | 100 | 82.5 | 0.0242 | 0.9758 | 0.7392 | 0.2608 | 0.1143 |
65~ | 35 | 32 | 3 | 63 | 47 | 0.0638 | 0.9362 | 0.6920 | 0.3080 | 0.2752 |
70~ | 28 | 26 | 2 | 28 | 15 | 0.1333 | 0.8667 | 0.5997 | 0.4003 | 0.5000 |
Age Groups | Cumulatively Observed Patients | Deceased Patients | Mortality Rate | Death Probability | Surviving Patients | Projected Died Patients | Surviving Person Years | Total Surviving Person Years | Life Expectancy |
---|---|---|---|---|---|---|---|---|---|
25~ | 495 | 2 | 0.0041 | 0.0201 | 100,000 | 2008 | 494,980 | 2,562,275 | 25.6 |
30~ | 489 | 4 | 0.0083 | 0.0408 | 97,992 | 3996 | 479,971 | 2,067,295 | 21.1 |
35~ | 468 | 22 | 0.0493 | 0.2193 | 93,996 | 20,617 | 418,438 | 1,587,325 | 16.9 |
40~ | 403 | 32 | 0.0848 | 0.3497 | 73,379 | 25,663 | 302,739 | 1,168,886 | 15.9 |
45~ | 320 | 10 | 0.0345 | 0.1590 | 47,716 | 7586 | 219,617 | 866,148 | 18.2 |
50~ | 249 | 16 | 0.0734 | 0.3101 | 40,130 | 12,444 | 169,543 | 646,531 | 16.1 |
55~ | 171 | 2 | 0.0147 | 0.0707 | 27,687 | 1957 | 133,542 | 476,988 | 17.2 |
60~ | 100 | 2 | 0.0242 | 0.1143 | 25,730 | 2941 | 121,299 | 343,445 | 13.3 |
65~ | 63 | 3 | 0.0638 | 0.2752 | 22,790 | 6272 | 98,267 | 222,146 | 9.7 |
70~ | 28 | 2 | 0.1333 | 0.5000 | 16,517 | 8259 | 123,879 | 123,879 | 7.5 |
Age Groups | Cumulatively Observed Patients | Life Expectancy | Without the Death Cause of Pneumonia | Without the Death Cause of Pulmonary Tuberculosis | Without the Death Cause of Lung Cancer | Without the Death Cause of Pulmonary Heart Disease | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Deceased Patients | Death Probability | Life Expectancy | Deceased Patients | Death Probability | Life Expectancy | Deceased Patients | Death Probability | Life Expectancy | Actually Died Patients | Death Probability | Life Expectancy | |||
25~ | 495 | 25.6 | 2 | 0.0201 | 29.9 | 2 | 0.0201 | 27.0 | 2 | 0.0201 | 26.8 | 2 | 0.0201 | 27.0 |
30~ | 489 | 21.1 | 2 | 0.0206 | 25.4 | 4 | 0.0408 | 22.5 | 4 | 0.0408 | 22.3 | 4 | 0.0408 | 22.5 |
35~ | 468 | 16.9 | 14 | 0.1466 | 20.9 | 18 | 0.1839 | 18.4 | 21 | 0.2106 | 18.2 | 20 | 0.2018 | 18.3 |
40~ | 403 | 15.9 | 23 | 0.2671 | 19.1 | 28 | 0.3143 | 16.9 | 27 | 0.3051 | 17.3 | 27 | 0.3051 | 17.3 |
45~ | 320 | 18.2 | 4 | 0.0675 | 20.1 | 10 | 0.1590 | 18.6 | 8 | 0.1297 | 18.8 | 9 | 0.1445 | 18.8 |
50~ | 249 | 16.1 | 12 | 0.2439 | 16.4 | 14 | 0.2778 | 16.6 | 15 | 0.2941 | 16.3 | 14 | 0.2778 | 16.6 |
55~ | 171 | 17.2 | 2 | 0.0707 | 15.8 | 1 | 0.0361 | 17.0 | 2 | 0.0707 | 17.0 | 1 | 0.0361 | 17.0 |
60~ | 100 | 13.3 | 2 | 0.1143 | 11.9 | 2 | 0.1143 | 12.6 | 1 | 0.0592 | 13.1 | 2 | 0.1143 | 12.5 |
65~ | 63 | 9.7 | 2 | 0.1942 | 8.1 | 3 | 0.2752 | 8.9 | 3 | 0.2752 | 8.8 | 3 | 0.2752 | 8.8 |
70~ | 28 | 7.5 | 1 | 0.2941 | 4.4 | 2 | 0.5000 | 6.3 | 1 | 0.2941 | 6.2 | 2 | 0.5000 | 6.2 |
Variable | Regression Coefficients | Standard Error | Wald χ2 Value | p Value | RR | 95% CI |
---|---|---|---|---|---|---|
Initial dust exposure Age | −0.104 | 0.015 | 47.025 | <0.001 | 0.902 | 0.875–0.929 |
Age of onset | −0.059 | 0.016 | 13.729 | <0.001 | 0.943 | 0.914–0.973 |
First diagnosis of age | 0.640 | 0.171 | 14.020 | <0.001 | 1.897 | 1.357–2.653 |
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Han, L.; Gao, Q.; Yang, J.; Wu, Q.; Zhu, B.; Zhang, H.; Ding, B.; Ni, C. Survival Analysis of Coal Workers’ Pneumoconiosis (CWP) Patients in a State-Owned Mine in the East of China from 1963 to 2014. Int. J. Environ. Res. Public Health 2017, 14, 489. https://doi.org/10.3390/ijerph14050489
Han L, Gao Q, Yang J, Wu Q, Zhu B, Zhang H, Ding B, Ni C. Survival Analysis of Coal Workers’ Pneumoconiosis (CWP) Patients in a State-Owned Mine in the East of China from 1963 to 2014. International Journal of Environmental Research and Public Health. 2017; 14(5):489. https://doi.org/10.3390/ijerph14050489
Chicago/Turabian StyleHan, Lei, Qianqian Gao, Jingjin Yang, Qiuyun Wu, Baoli Zhu, Hengdong Zhang, Bangmei Ding, and Chunhui Ni. 2017. "Survival Analysis of Coal Workers’ Pneumoconiosis (CWP) Patients in a State-Owned Mine in the East of China from 1963 to 2014" International Journal of Environmental Research and Public Health 14, no. 5: 489. https://doi.org/10.3390/ijerph14050489