The group of test participants covered by Health Protection Agency's study consists of over 20,000 servicemen and civilians who took part in the tests and a carefully matched control group of a similar size. Controls had served in tropical or sub-tropical areas, but not in test locations. About 85% of those meeting the definition of test participation are included.
The information about causes of death in this study is obtained only from death certificates and cancer registrations. Post-mortems are not part of the study. If participants have post-mortems for other reasons then the findings are duly recorded in the death certificate from which the study gets its information.
Three thorough studies have been carried out since the 1980s and the results have been published in science journals. Through the nuclear test veteran organisations, nuclear test veterans and their families have been kept informed about the studies since their inception in 1983 and the researchers have long been committed to providing the results of studies to the test veterans in advance of publication. The publications are in the public domain and are usually well reported in the news media.