Risk factors associated with the classification of unspecified and/or unexplained causes of death in an occupational cohort.

In a matched case-control study of an occupational cohort in East Tennessee, data from the death certificates of 608 cases and controls were abstracted and analyzed in order to investigate possible risk factors associated with the certification on the death certificate of an ill-defined cause of death. There was a very strong association between the ill-defined classification and the certifier, especially if the certifier was a medical examiner (OR = 10.4, 95% CI: 6.0, 18.0).