Information about occupational exposure to asbestos given to cases in an etiological study: ethical aspects

The aim of the study is to consider some ethical aspects of the provision of information, to the cases or their families, about the assessment of occupational asbestos exposure obtained in a case-control study of malignant mesothelioma of the pleura. An informative letter with the result of the evaluation of their occupational exposure to asbestos was sent to the participating cases (and/or their family). Those whose exposure was classified as certain/probable were also informed of the legislation regarding occupational diseases. Of the 132 cases, 32.6% of subjects and/or their families made telephone calls expressing interest in the content of the informative letter. Among the 63 cases classified as certain/probable exposure, this proportion was 47.6%. Out of 43 cases in which the age at diagnosis was < or = 65 years and the exposure to asbestos was certain/probable, only two (4.6%) were signed off work owing to occupational disease. Only one of the mesothelioma cases was recognized by the Spanish National Institute for Social Security (INSS) as having an occupational disease. The process of communication of the results of an epidemiological research should include the provision of information on the exposure data to each one of the subjects, and/or their families. There is a great disparity between the number of cases of certain/probable exposure to asbestos identified in our study, and the number registered as an occupational disease by the INSS.