Many occupational cohort studies rely upon the cause of death listed on death certificates for assessing cancer. Yet this information is often not accurate. See, e.g., Wissing, et al. (2019); Tan (2019). This is particularly relevant when assessing mesothelioma incidence.
Boffetta, et al. (2018) illustrates the potential for misclassifying mesothelioma. The authors “searched medical and pathology records and specimens for 127 workers from a textile asbestos factory in Italy who died during 1963-2013 with a diagnosis of pleural or peritoneal neoplasm or mesothelioma on death certificate, to confirm the diagnosis with immunohistochemistry (IHC) markers.” The authors were able to confirm only a small proportion of mesothelioma diagnoses: “The diagnosis of mesothelioma was histologically confirmed for 35 cases (27.6%); 5 cases were classified as non-mesothelioma (3.9%), for 33 cases a mention of mesothelioma was found on record but no sufficient material was available for revision (26.0%); no records were available for 54 cases (death certificate-only 42.5%).”
This “study shows that for a relatively large proportion of members of historical cohorts of asbestos workers, the information on pleural or peritoneal cancer/mesothelioma reported on death certificates cannot be validated through medical or pathology records, and even less so with review of pathology material.”
– Ray Harris