Background Respiratory diseases, including pneumoconiosis, asthma, chronic obstructive pulmonary disease (COPD) and respiratory malignancies, are featured by their multi-etiological nature and long latency periods, adding to the difficulties in recognizing their work-relatedness. Due to their heavy overall disease burdens and high healthcare spending, examining the fraction of respiratory diseases attributable to occupational factors is helpful in understanding the magnitude of under-estimation of occupational injuries and diseases.

Methods Prevalence rates of various occupational exposures were assessed retrospectively with self-reported surveys or job-exposure matrices. Relative risks of theses exposures were drawn from international epidemiological literatures. The above two parameters were used to calculate population attributable risk percentages (PAR%), and with that the numbers of visiting and amounts of payment attributable to occupational factors were estimated based on the claim data of the National Health Insurance (NHI). The estimates were compared with the data of actual payment by the Workers’ Compensation Insurance (WCI).

Results We estimated that around 15 000 patients visited medical facilities for occupational respiratory diseases in 2015, costing a total of 10 million USD. In contrast, less than 200 cases were approved by WCI in the same year. A 100-fold gap between the estimated and actual payment was also noted. Estimation analyses further indicated that 9.6% of cases and 48.1% of healthcare costs were asbestos-related.

Conclusion For occupational respiratory diseases with long latency periods and great causal complexity, the scope of under-estimation was substantial, and their medical expenses had been largely paid by NHI rather than WCI. To increase the visibility of occupational respiratory diseases, workplace exposure assessment and disease surveillance should be improved and public awareness of occupational diseases should be raised.