Survival and disease burden of pneumoconiosis patients in Nanjing, 1956 – 2021: a retrospective follow-up analysis

  Objective  To examine the survival, disease burden and their associates among pneumoconiosis patients reported in Nanjing city during 1956 – 2021 for developing targeted measures on pneumoconiosis prevention and control.

  Methods  The records of 3456 confirmed pneumoconiosis patients reported in Nanjing from 1956 through 2021 were extracted from the Information Management System for Occupational Disease Prevention and Control of Jiangsu Province and face-to-face or telephone interviews were conducted among the patients in October 2022 for a follow-up survey. Life table and the Kaplan-Meier methods were used in survival analysis, and Cox proportional hazard regression model was applied to analyze influencing factors of survival time. Disease burden of pneumoconiosis was assessed comprehensively using disability adjusted life years (DALY), years of life lost (YLL), and years lost due to disability (YLD).

  Results  Of the 3 333 patients with valid responses, 89.3% were male; 89.3% had stage I pneumoconiosis at the first diagnosis; and 72.1% were diagnosed as silicosis. The median survival time for all the patients up to December 31, was 30.20 (95% confidence interval 95%CI: 29.53 – 30.86) years. The results of Cox proportional hazard regression analysis showed that aged ≥ 30 years and having stage III pneumoconiosis at the first diagnosis were risk factors of low survival; while, being female and being engaged in manufacturing industry were protective factors of survival for the patients. In terms of disease burden caused by pneumoconiosis during the follow-up period for all the patients, the person-years of total cumulative DALY, YLD, and YLL were 27 529.49, 23 440.46, and 4 089.03 and the years of per capita DALY, YLD, and YLL were 8.26, 7.03, and 2.53, respectively. Significantly declining trend over the follow-up period was observed in years period per capita DALY (χ²_trend = 776.437), YLD (χ²_trend = 206.153), and YLL (χ²_trend = 1 040.571) (P < 0.001 for all). The highest year period-specific YLD (10 042.02 person-years) and DALY (10 619.02 person-years) were observed in 1991 – 2000 but the year period-specific YLL increased gradually over the follow-up period, with the highest of 1 956.35 person-years for the years from 2011 to 2021.

  Conclusion  The prevalence of pneumoconiosis among workers in Nanjing city was generally under control during 1956 – 2021 but the disease burden caused by the occupational disease still needs to be concerned, especially among groups at higher risk of the disease.