Could the 15% of test participants who were not included in the study have experienced very different health outcomes to the 85% who were included?
The question of potential bias of the study population derived from MoD records is an important one and the researchers were alert to it from the start. The work that was undertaken to investigate such a possibility is discussed in detail in the published reports. In particular, in addition to the lists compiled from official sources, the NRPB/HPA researchers were also able to assemble a list of test participants from sources independent of MoD. It was this list which enabled the researchers to estimate that approximately 15% of individuals may not have been included on the list compiled from MoD records. Looking at the total group of people identified from independent sources (including those that had also been identified from the MoD records), it was apparent that the health experience of the people included on this independent list was worse than that expected from comparisons with the general population and also worse than the participant group identified from the contemporary MoD
