Estimating impacts of asbestosrelated malignant mesothelioma: Quantification of life expectancy lost and lifetime healthcare expenditures in Taiwan

Malignant mesothelioma (MM) can be considered as a marker malignancy related to previous asbestos exposure. This study determines the impact of MM using average life years lost and lifetime healthcare expenditures in Taiwan. We collected patients diagnosed with pleural MM (ICD-O 163) and peritoneal MM (ICD-O 158) during 1998-2009 with histological evidence from the Taiwan Cancer Registry (TCR), which were inter-linked with the National Mortality Registry (NMR) and the National Health Insurance (NHI) reimbursement database up to 2011 to estimate survival and lifetime direct medical costs. For each MM patient, we simulated age-and gender-matched referents based on the vital statistics of Taiwan to estimate expected years of life lost (EYLL). We extrapolated lifetime survival function by a semi-parametric method after 14 years of follow-up. The mean monthly direct medical costs were calculated, multiplied with the corresponding survival probability, and summed up throughout life for the lifetime healthcare expenditures (LTHE) after adjustment for annual discount rate of 3%. A total of 300 cases of pleural MM, and 106 cases of peritoneal MM were identified in the TCR during 1998-2009. The average EYLL for pleural and peritoneal MM was 18.2 (95% confidence interval [CI]: 17.9-18.4), and 19.1 (95% CI: 18.5-19.8) years, respectively. Estimated LTHE with a 3% annual discount was $ USD 29,400 (95% CI: 24,200-33,000) for pleural MM and 27,200 (95% CI 20,500-32,000) for peritoneal MM. As MM has been under-diagnosed in Taiwan, such estimates provide lower bounds for potential saving of society on total ban of asbestos.