Study of estimation method for incidence of new cases of coal workers' pneumoconiosis in China

Abstract

To estimate the coverage level of case reporting for coal workers' pneumoconiosis (CWP) and the incidence of CWP in China according to the data from CWP reporting database in China as well as the data on annual raw coal output, coal workers, etc. from relevant year books, and to provide scientific data for CWP control measures. The data on the numbers of coal workers and annual raw coal outputs of national top 100 enterprises in coal sector (Top 100 in coal sector) were acquired from China Coal Industry Yearbook; the annual per capita output of raw coal in each enterprise was calculated. The numbers of coal workers in the enterprises other than the Top 100 were estimated based on the annual per capita output of raw coal in the Top 100 and the annual raw coal outputs of the enterprises other than the Top 100. The numbers of coal workers in the enterprises that reported CWP cases were estimated based on the distribution of these enterprises in China, and the coverage rates of case reporting in the Top 100 and other enterprises were calculated accordingly. The total number of CWP cases and the number of CWP cases due to per million tons of raw coal output were estimated according to the coverage rates of case reporting and the total numbers of reported CWP cases in China. The mean coverage rates of case reporting in the Top 100 and other enterprises were 55.34% and 5.18%, respectively. The estimated mean numbers of new CWP cases in the Top 100 and other enterprises were 3088 and 98205, respectively; the estimated total number of new CWP cases nationwide was 101293. The estimated mean numbers of new CWP cases due to per million tons of raw coal output were 2.05 in the Top 100 and 7341 in other enterprises. The number of reported CWP cases accounted for 6.7% of the estimated number of CWP cases (6796/101293). It is urgent to enhance occupational disease control in coal sector, and the estimation results for CWP should be spread and applied. The system of occupational disease control should be further improved.