Prevalence of coal worker's pneumoconiosis: a systematic review and meta-analysis

Global prevalence trend and regional differences of coal worker's pneumoconiosis (CWP) remain unclear. This study aimed to provide systematic and comprehensive evidence for the global prevalence of CWP. Literature research for studies that reported prevalence of CWP was conducted in PubMed, CNKI, and Web of Science. The identified studies were strictly screened according to predetermined inclusion and exclusion criteria. The pooled prevalence of CWP in different periods and regions was calculated. A total of 37 studies were included after screening, and data from the Coal Workers' Health Surveillance Program was additionally included in the meta-analysis. The global pooled prevalence of CWP decreased from 23.33% (95% confidence interval [CI]: 18.03%, 28.62%) before 1970 to 6.00% (95% CI: 4.11%, 7.90%) in 1981-1990, but indicated a rebound (10.35%, 95% CI: 8.08%, 12.62%) in 1991-2000 and finally dropped to 2.29% (95% CI: 2.06%, 2.51%) in 2011-2020. In the recent 30 years, the top three pooled prevalence of CWP was found in Europe, China, and the USA, respectively. Few articles have reported the prevalence in developing regions, but available evidence indicated that the prevalence in developing regions was much higher than that in developed regions. Higher pooled prevalence was observed in studies which reported larger number of miners in collieries, older average age of miners, underground collieries, and longer dust exposure time. The global prevalence of CWP indicates a rebound in 1990s, but the overall trend is downward in the recent 60 years. The prevention and treatment of CWP should be currently emphasized in developing countries.

Automated summary

This study investigated the global prevalence trend and regional differences of coal worker's pneumoconiosis (CWP) and found that the global prevalence of CWP has been declining over the past 60 years, with a rebound in the 1990s. Europe, China, and the USA have had the highest prevalence of CWP in the past 30 years. The prevalence in developing countries is higher than that in developed countries. Factors such as longer work duration, older age, and working in underground coal mines are associated with a higher prevalence of CWP. The prevention and treatment of CWP should be focused on in developing countries.